Ca18det haters

[redtop91]

LOL at this discussion. CA=SR

/thread

[Liquid_Neon]

alright, yeah, i like to feed this kinda thing a little bit. I jsut like to argue.

im done now

[bias]

Come on people? Why are we starting to bash Srs? This was suppose to be a thread for us CA owners to laugh at all those who think our engines are a joke. Not a comparison of which is the best. With "Big Pockets" and the brain power to put things together, any motor can be better than any other. It's not about the displacement,rpm,heads, or any of that stuff. Who has the know how and the money to make it happen. I take pride in my engine choice. If I get beat by an SR who cares? "There Are Many Fast Cars But This One is Mine"!

[float_6969]

That nailed for me right there!

[r34 gtr]

word.

[float_6969]

word up.

[themadscientist]

Flow bench is ****. A running engine with opening and closing valves, the airflow starting and stopping and starting again is nothing like the steady state of a flowbench.

The SRs valvetrain is terrible by comparison, no can defense danielsan.Does it work? Yes it does work, Nissan builds good motors. Both motors rev, I never got the whole "revability" thing myself and both motors will suffer rev limitations based on the hydraulic components in their valvetrain but cam on bucket is better. The undercam rocker thing is an L design revistited but made worse by having one arm actuate two valves.

The CA has all the stops pulled out, it was cutting edge for it's time. No it was not a copy of the 4AG, that is a pretty assinanine statement. The whole design of the SR is "good enough". That's why it's so often pointed out to be cheap.

The CA was old and it's time had come. Just like all the great motors before. The SR has earned it's stipes too and will be remembered fondly as well when it goes. I don't even know what is in the pipe next on the four cylinder.

I am not an SR hater, I don't like it to be sure but I would not deny it it's due. I hear on average less silly comments like you have outlined from CA guys than I do from SR guys though. There are more "haters" on the 2-liter side of the fence than over here. SR20 owners seem to have some elitist kick going that fosters a negative backlash from CA, KA, and RB owners.

I do find the different personalities of the individual engine owners fun to notice. Certain types seem to gravitate to one or the other more on personal preference than actual hard quantitative facts about their needs and the engine in questions capability.

I always seem to be on the underdog side. When guys were running FJ I was running L, when others were running RB25s I ran an RB20, Majority these days being pulled around by SRs I roll the CA. It's my personality and my style that make me pick the CA. I wish it had stuck around longer and Nissan had taken it to a third generation but they didn't so we will never know. They have chosen to continue refining the SR but were I to rock one I would probably go with an old wardog redtop with none of that variable timing crap. Again, the raw simpler motor would appeal to me over the more sleek refined humpback SRs.

[r34 gtr]

damn! every CA hater just got stared down upon with disdain from the spooky mountaintop castle.

[AmoebAssassin]

Flow bench is ****. A running engine with opening and closing valves, the airflow starting and stopping and starting again is nothing like the steady state of a flowbench.

The SRs valvetrain is terrible by comparison, no can defense danielsan.Does it work? Yes it does work, Nissan builds good motors. Both motors rev, I never got the whole "revability" thing myself and both motors will suffer rev limitations based on the hydraulic components in their valvetrain but cam on bucket is better. The undercam rocker thing is an L design revistited but made worse by having one arm actuate two valves.

The CA has all the stops pulled out, it was cutting edge for it's time. No it was not a copy of the 4AG, that is a pretty assinanine statement. The whole design of the SR is "good enough". That's why it's so often pointed out to be cheap.

Once again, a CA18 owner stating "facts" with no factual evidence.

Can you explain to me why one cam lobe actuating two valves is a detriment?Can you explain to me why bucket-tappet valvetrains are better than rocker valvetrains?Can you explain to me why the SR's valvetrain is "terrible by comparison"?Do you have a broad enough understanding of 1970-1980 engine design to state that the CA18 was "cutting edge" and not be doing anything more than blowing more hot air?

Probably not.

Oh, by the way -- go to any respectable engine builder and tell him flow bench ratings don't matter. Then watch as you get laughed out of his shop. If you don't believe that head flow rates can indicate performance, then please, don't bother ever upgrading your camshafts, or porting your head, or seating larger valves, etc. etc.

[themadscientist]

Once again, a CA18 owner stating "facts" with no factual evidence.

As said by the SR guy with similar credentials

Can you explain to me why one cam lobe actuating two valves is a detriment? Can you explain to me why bucket-tappet valvetrains are better than rocker valvetrains?

one more part to flex, one more part to break, one more part to go out of adjustment. The fact that I have to explain it to you speaks volumes. If you could perform the same work by picking up a rock directly or use a lever on another rock to do the work, which is better? Wait, don't rush to answer, the other rock that you are using as a fulcrum is at the opposite end of the lever, you must pick it up by the middle of the lever. Think, I know it might challenge you but give it a shot. (take note, the work in the engine is push rather than pull but the work is the same in either direction)

Can you explain to me why the SR's valvetrain is "terrible by comparison"?

I just did, reveiw and absorb.

Do you have a broad enough understanding of 1970-1980 engine design to state that the CA18 was "cutting edge" and not be doing anything more than blowing more hot air?

Well considering I was out there on the street fighting all manner of engines of that era in country I think I have a better understanding of what was on the street than you. For it's time, the design of the CA was what other manufacturers were working with. The SRs design however is not revolutionary, it is actually a step backwards. The CA was in tune with the time it lived in, the SR was old when it was new. This would be like V8 guys touting the return of pushrods. Maybe that metaphor is lost on you since I had to earlier explain the disadvantage of adding extra parts to the valvetrain.Probably not.

Oh, by the way -- go to any respectable engine builder and tell him flow bench ratings don't matter. Then watch as you get laughed out of his shop.

Study some, port velocity in particular. An engine does not flow in a steady state. I know engine builders on both sides of the fence, the facts I have studied in technical manuals and what I have personally seen from both sides of the argument show me that a measurement of a machine based on a condition it will never see used as a tuning guide is a fools exercise. These same experts would have you stick a tiny exhuast housing on a car for response. Then they cannot understand why a housing designed to make power at 2000 rpm falls off at 7000. I don't beleive what people say, I watch what they do. I don't look at a parts list I run the ****er and see what it does. There is a reason I can do the things I do. There is a reason I can take an L20 and knock out an FJ20, there is a reason I can take an RB20 and hold off an RB25, there is a reason I can take a CA18DE and run down an RB20DE****INGT son!I would like to have a nice discussion about the two, their strengths and weaknesses because neither is the perfect weapon but if you want to have a pissing match instead, that's fine too, you will get wet. kisses

[r34 gtr]

why come all the way to the CA forum to pick pointless fights? i dont go barging into the SR forum talking trash. get out of my house!

[themadscientist]

That is something some (not all) SR guys do. That gets back to what I was saying about the personalities of the different engine owners.

CA guys tend to be frugal crafty guys who are self-effacing until attacked then we swarm like bees on the offender like what happened to create this very thread.

SR guys (again, not all but many) like to pick fights and will troll other areas looking for a fight. CA guys are happy to oblige, not sure about KA guys.

RB guys are convinced they have the perfect engine and rarely leave their area and feel no need to even interact with the others.

KA guys, I don't have a lot of experience with but the few i have dealt with seem to have a lot of the same traits as CA, DIY types with a good group cohesivness but less likely to swing at a minor slight.

If the engine forum were a party I see it like this.

RB guys in the corner drinking imported beer and talking only to each other.

KA guys dancing and working the crowd drinking Coronas.

SR guys doing tequila shooters and trying to start something with someone else for looking at their girl.

CA guys playing darts with no dartboard, just a circle drawn on the wall and drinking stuff they snuck in.

[redtop91]

i dont go barging into the SR forum talking trash. get out of my house!

No but I'd rather you do that than snicker in seclusion and bash a motor that is equal to yours. There should be a neutral sticky where all motors are discussed. There is no reason to continue this thread.

[themadscientist]

No but I'd rather you do that than snicker in seclusion and bash a motor that is equal to yours. There should be a neutral sticky where all motors are discussed. There is no reason to continue this thread.

That is a good point redtop, I agree with you. I would love it if nobody bashed anybody, I have yet to encounter a Nissan motor that was not a good one. Peoples emotions get involved when discussing them because they are such personal choices, I don't think we could ever have that. It's like brothers fighting, dumb unnecessary and in the end pointless.

[adam-gtX]

why cant sr owners not except that the ca is a good engine (not saying the sr is bad because its not) Its almost as if it kills them to ponder a engine as good as thirs

[themadscientist]

I think every engine has it's militants, the CA too. The whole "race design" thing still confuses me. To my knowledge (whatever that amounts to) Nissan never campaigned any race car with a CA engine. The SR can say that. If anybody has some supporting info that there were CA-powered Nissan racecars, not shopcars or homebuilt that were involved in competition I would like to see it.

[AmoebAssassin]

As said by the SR guy with similar credentials

The difference is, I dont go around making fallacious or dubiously supported claims, whereas you do. I simply asked you to prove something to me in a logical, scientific manner and you could not.

Quote »one more part to flex, one more part to break, one more part to go out of adjustment. The fact that I have to explain it to you speaks volumes. If you could perform the same work by picking up a rock directly or use a lever on another rock to do the work, which is better? Wait, don't rush to answer, the other rock that you are using as a fulcrum is at the opposite end of the lever, you must pick it up by the middle of the lever. Think, I know it might challenge you but give it a shot. (take note, the work in the engine is push rather than pull but the work is the same in either direction)[/quote]I'm two semesters away from my B.S. in Mech Eng, so you don't have to coddle to me with dumbass examples that I could maybe relate to in 2nd grade, kthx.

Okay, let's use your own argument. Picking a rock up in "steady state" is a lot different than a camshaft revolving at engine speed. Oversimplifying, then, is "an excercise in foolishness," correct? Engines at speed present lots of variables to consider, so let's consider them.

Firstly, you reduce both the mass and rotational moment of inertia of your camshaft in the SR head. Since there are fewer lobes, there is less mass and it is more centralized around the rotational axis of the motor, allowing the camshaft to accelerate more quickly and with less resistance.

Additionally, with the SR's actuation design, there is less friction than in the CA18 head. With only one friction surface between cam and rocker for two valves, you've halved your friction surface, and thereby reduced frictional forces and head/cam oiling requirements.

While SR20s may have more reciprocating valvetrain mass than CA18s, they more than make up for it by the inherent ability of a rocker arm setup to run higher lift profiles, and more aggressive valve opening profiles. With a bucket-tappet setup, you find a limit when your valve ramp up is so steep that you essentially start slapping your cam opening face against your valve bucket. Also, your off-axis (sideways) loadings are much larger in cam on bucket systems than in rocker systems, increasing friction and wear between your valve stem and valve guides.

Quote »Well considering I was out there on the street fighting all manner of engines of that era in country I think I have a better understanding of what was on the street than you. For it's time, the design of the CA was what other manufacturers were working with. The SRs design however is not revolutionary, it is actually a step backwards. The CA was in tune with the time it lived in, the SR was old when it was new. This would be like V8 guys touting the return of pushrods. Maybe that metaphor is lost on you since I had to earlier explain the disadvantage of adding extra parts to the valvetrain.Probably not.[/quote]Oh boy, street racing sure gives you some sweet credentials on engine design, right? By the way, thanks once again for attempting to make an argument with no numbers or design analysis to support your claim.

Oh, and by the way, there's nothing wrong with pushrods. Its not elegant, but it is a simple design, and it works well. The only disadvantage of the system is it does not provide for independent tuning of exhaust and intake cam openings and closings without buying a new cam.

Adding parts to your valvetrain is not bad, as long as you properly engineer them. Go tell a C6 Z06 owner that his LS7 is crap because it has rocker arms and pushrods, even though it makes 500+hp and spins to 7000rpm. If he gives you flak, you could probably street race him and shut him up, right? Because you're what, like, 40 and you still street race? Man you're awesome.

Quote »Study some, port velocity in particular. An engine does not flow in a steady state. I know engine builders on both sides of the fence, the facts I have studied in technical manuals and what I have personally seen from both sides of the argument show me that a measurement of a machine based on a condition it will never see used as a tuning guide is a fools exercise. [/quote]Here, i've studied a little bit about fluid mechanics, i'll clue you in on something called head loss, and why flow benches DO indicate engine performance.

Head loss describes the amount of energy any given flow in a pipe will lose due (most practically with respect to our argument) to frictional effects over rough internal surfaces, and minor losses due to sudden changes in piping diameter (the interface areas between manifolds and ports, etc.). What a flow bench reveals is how much flow energy a head will dissipate because of it's design and construction. At a standard pressure differential, a higher flowing head robs less energy from flow and thus, has less fluid friction forces restricting flow in the head -- you can deduce then, that there is less frictional resistance in the higher flowing head.

Now, why don't we look at an operating engine, not in steady state, and with valve openings and closings. Since you're interrupting and halting flow with valves, you must have to accelerate air through your head once you valves open, correct? Accelerating fluids in the presence of frictional forces requires the engine to expend more power on it's induction cycle, reducing it's efficiency and ultimate power output. Hence, the head that flows more on a flowbench has less frictional resistance, and thus will be more efficient and prone to making power under actual operating conditions.

Use of flowbenches at standard conditions is a great way to compare different heads, and the reduction in losses you develop by upgrading your valvetrain.

Quote »These same experts would have you stick a tiny exhuast housing on a car for response. Then they cannot understand why a housing designed to make power at 2000 rpm falls off at 7000. I don't beleive what people say, I watch what they do. I don't look at a parts list I run the ****er and see what it does. There is a reason I can do the things I do. There is a reason I can take an L20 and knock out an FJ20, there is a reason I can take an RB20 and hold off an RB25, there is a reason I can take a CA18DE and run down an RB20DE****INGT son!I would like to have a nice discussion about the two, their strengths and weaknesses because neither is the perfect weapon but if you want to have a pissing match instead, that's fine too, you will get wet. kisses [/quote]Stupid is as stupid does I suppose -- Kudos to you for ignoring what stupid people have to say. A civilized discussion would be nice, but it's very difficult with you condescending to me at every step of your argument.

[kapower06]

And one more thing.The CA did cost more to produce and took more time. time=money to business's.

And one of the main reasons that Nissan quit producing the CA was that the cost of IRON was outrageous in the late early 90's so they had to produce another engine to take the CA's spot, one that was cheaper and faster to build, this is were the SR comes in.

And for your lil comparo of the c6 z06... I personally think its funny that people believe that 505hp is alot. Yes it is alot, but not from a freaking 7 liter motor. Lets see, stock ca18det is putting out 175hp (not whp) thats damn near 100hp/liter. with a simple exhaust and air filter the power is well over 175hp (not whp) then take into example the rb26 or the s15 sr20, they both make well over 100hp/liter. All im saying is don't go making the ls7 seem like the god send motor, SEVEN liters, WAYYYYYY under 700hp? funny?

All in all im not bashing the SR20 or the ls7 just saying that anything can be made to go fast, we all just have different ways of achieving how we get to our goal.

[themadscientist]

The difference is, I dont go around making fallacious or dubiously supported claims, whereas you do. I simply asked you to prove something to me in a logical, scientific manner and you could not.

Reading is fundamental, try it again. You do exactly what you would denounce me for. Hipocracy is unattractive.

I'm two semesters away from my B.S. in Mech Eng (which I'm assuming is more formal education than you have in the field) so you don't have to coddle to me with dumbass examples that I could maybe relate to in 2nd grade, kthx..

Apparently you couldn't relate to them in second grade, nor now. Congratulations on your schooling, it means you read books. I read books too. I know too many people in too many diverse feilds who hide behind a diploma but can't do **** to back it up. I see "certified technicians" do dumb **** all the time. It doesn't mean a thing to me.

Okay, let's use your own argument. Picking a rock up in "steady state" is a lot different than a camshaft revolving at engine speed. Engines at speed present lots of variables to consider, so let's consider them..

Again you failed to read. Better learn how I assume they still test you on things before they give you sheepskin. The steady state is in reference to the flowbench not the cam. Try again.

Firstly, you reduce both the mass and rotational moment of inertia of your camshaft in the SR head. Since there are fewer lobes, there is less mass and it is more centralized around the rotational axis of the motor, allowing the camshaft to accelerate more quickly and with less resistance..

That's a fun one, I'll play along. All I have is a kitchen scale but I will go home tonight and weigh a CA cam, you weigh an SR one and we will see what we get. We have no way to measure moment of inertia here though but I know of the phenmenon of which you speak. Could we measure it I may have to award you a half point. The CA cams have narrower lobes compared to the SR though, it is tough to say which has more rotational mass, they would likely score very closely to each other on that.

Additionally, with the SR's actuation design, there is less friction than in the CA18 head. With only one friction surface between cam and rocker for two valves, you've halved your friction surface, and thereby reduced frictional forces and head/cam oiling requirements..

Now that is a solid point and worth mention, you definately earned that one.

While SR20s may have more reciprocating valvetrain mass than CA18s, they more than make up for it by the inherent ability of a rocker arm setup to run higher lift profiles, and more aggressive valve opening profiles. With a bucket-tappet setup, you find a limit when your valve ramp up is so steep that you essentially start slapping your cam opening face against your valve bucket. Also, your off-axis (sideways) loadings are much larger in cam on bucket systems than in rocker systems, increasing friction and wear between your valve stem and valve guides.

In general theory possibly but in actual use the SR ehxibits pronounced valve guide wear vs the CA and RB which are cam on bucket. This means more friction which will likely bring you back a step from the gain you made above. It may be the angle that the valve is on the SR, it may not be an all-the-time occurance with the fulcrum type valvetrain but it happens here.

Oh boy, street racing sure gives you some sweet credentials on engine design, right? By the way, thanks once again for attempting to make an argument with no numbers or design analysis to support your claim..

It don't take a degree to see what is out there. The CA was on par with it's competion at the time in all design features, the SR is retro. Sorry if the dumb guy who doesn't kiss your *** because you read a textbook and think you have all the answers won't take the opinion based on what classes you took.

Oh, and by the way, there's nothing wrong with pushrods. Its not elegant, but it is a simple design, and it works well. The only disadvantage of the system is it does not provide for independent tuning of exhaust and intake cam openings and closings without buying a new cam.

I never said the pushrod was bad, just not as good. Man you don't read at all do you? SOHC motors suffer the same problem regarding independent tuning of exhuast and intake timing, not a pushrod only issue.

Adding parts to your valvetrain is not bad, as long as you properly engineer them. Go tell a C6 Z06 owner that his LS7 is crap because it has rocker arms and pushrods, even though it makes 500+hp and spins to 7000rpm. If he gives you flak, you could probably street race him and shut him up, right? Because you're what, like, 40 and you still street race? Man you're awesome.

Adding parts when it is unnecesary of course. Were the pushrods to go away the motor would likely do better.Let's see You have a 5.7 liter motor making 500hp (does math, curses himself for not getting that engineering degree so he could be all self-impressed like somebody) That's 87.71 hp per liter. Now somebody find me some particulars on it, compression ratio etc because here is what I put up against it the weak, pathetic old CA18DE(no turbo).1.8 liters making 150hp, (help me dude the math just hurts my highschool-educated brain and you are so smart) 83.33 hp per liter. This is in 1989 with 9.5:1 compression and grandma camshafts compared to the vette.

Now, I won't race the vette, it's more powerful and I wouldn't have a chance. Pound for pound though it ain't showing me much over my old CA. I am 34 by the way, don't age me and I do occasionally streetrace. Oh wait, that's one of those things where you think you are better than me again. Tell yourself whatever you need to to feel good about yourself. You read, I read, you talk, I do.So what is so great about the vette motor? That's the best they can do in this day and age? I wouldn't brag too much about that, it's embarassing when taken into context. Just for ****s let me give you the SR20DE (S13 model, I am pretty sure the later models had a bit more but this is era-correct and NA because I want to compare apples to apples) 160HP at 2 liters (help me einstein how much is that?) Yeah 80hp per liter, huh? How could that be? the SR is king! it has this nostalgic valvetrain that pwns the CA but pound for pound makes less power, dumb guy confused.

Here, i've studied a little bit about fluid mechanics, i'll clue you in on something called head loss, and why flow benches DO indicate engine performance.

Head loss describes the amount of energy any given flow in a pipe will lose due (most practically with respect to our argument) to frictional effects over rough internal surfaces, and minor losses due to sudden changes in piping diameter (the interface areas between manifolds and ports, etc.). What a flow bench reveals is how much flow energy a head will dissipate because of it's design and construction. At a standard pressure differential, a higher flowing head robs less energy from flow and thus, has less fluid friction forces restricting flow in the head -- you can deduce then, that there is less frictional resistance in the higher flowing head.

Now, why don't we look at an operating engine, not in steady state, and with valve openings and closings. Since you're interrupting and halting flow with valves, you must have to accelerate air through your head once you valves open, correct? Accelerating fluids in the presence of frictional forces requires the engine to expend more power on it's induction cycle, reducing it's efficiency and ultimate power output. Hence, the head that flows more on a flowbench has less frictional resistance, and thus will be more efficient and prone to making power under actual operating conditions.

Use of flowbenches at standard conditions is a great way to compare different heads, and the reduction in losses you develop by upgrading your valvetrain.

The only way to truly see what the head will do is to put it into operation in the real world. You are measuring a situation the engine will never see I suppose you would bore a block without a torque plate as well. It measures perfect sitting there on the floor smart guy number one, well smart guy number 2 lets put it together then. The head doesn't live on a vacuum table, it lives on a engine with all types of variables you have removed so you can say "well this one flows more air in the completely unrealistic arrangement than the other one so it must be better". This would be like religiously watching an air/fuel meter and using that as the only guideline and not adjusting it to make peak power in the range the motor will be living in. The dyno is where you tune, with the motor operating in the state it will live in.

Stupid is as stupid does I suppose -- Kudos to you for ignoring what stupid people have to say. A civilized discussion would be nice, but it's very difficult with you condescending to me at every step of your argument.

I think my posts in this thread say all I need, yours speak for you as well. I have been respectful when it was called for (everybody else and to your engine by the way) and firm when requested by the others conduct (you). Don't get butthurt. If you read you will see I don't hate on the SR but I am brutally honest about it and I am not afraid to turn that lens inward to the CA. I think you will find I am not an SR hater. I don't really hate any engine, well ok that 1.9 Opel motor was a ***** but that was because the timing mark was on the damned flywheel.

[themadscientist]

And one more thing.The CA did cost more to produce and took more time. time=money to business's.

And one of the main reasons that Nissan quit producing the CA was that the cost of IRON was outrageous in the late early 90's so they had to produce another engine to take the CA's spot, one that was cheaper and faster to build, this is were the SR comes in.

And for your lil comparo of the c6 z06... I personally think its funny that people believe that 505hp is alot. Yes it is alot, but not from a freaking 7 liter motor. Lets see, stock ca18det is putting out 175hp (not whp) thats damn near 100hp/liter. with a simple exhaust and air filter the power is well over 175hp (not whp) then take into example the rb26 or the s15 sr20, they both make well over 100hp/liter. All im saying is don't go making the ls7 seem like the god send motor, SEVEN liters, WAYYYYYY under 700hp? funny?

All in all im not bashing the SR20 or the ls7 just saying that anything can be made to go fast, we all just have different ways of achieving how we get to our goal.

No ****? 7 liters? my god it's worse than I thought! 71.42hp per liter, haha.

[Dirty Dee]

http://online.physics.uiuc.edu....html

here is some formulas if you want to attempt measuring the Moments of inertias of the cams (I am bored)

[themadscientist]

Good stuff. I got a cam out of the engine, anybody have an SR cam we can test? I think it would be fun to try at least, with a few rum and cokes to lubricate the tester at least.

[float_6969]

So why exactly are you here? What is your purpose in posting in this thread? What do you hope to achieve?

Do you honestly think that you're going to come in here touting a degree that you don't have yet and show us all the error of our ways? Enlighten us to the engineering marvel of the SR? Do you expect us to thank and praise your for your much desired knowledge?

Stupid is as stupid does I suppose -- Kudos to you for ignoring what stupid people have to say. A civilized discussion would be nice, but it's very difficult with you condescending to me at every step of your argument.

You speak of having the desire to have a level headed legitimate discussion covering the various differences and pro's and con's of the various motors, but aren't able due to TMS's "condescending" post. Yet from my view you are the one that introduced yourself into this thread with condescension.

Here, i've studied a little bit about fluid mechanics, i'll clue you in on something called head loss, and why flow benches DO indicate engine performance.

Head loss describes the amount of energy any given flow in a pipe will lose due (most practically with respect to our argument) to frictional effects over rough internal surfaces, and minor losses due to sudden changes in piping diameter (the interface areas between manifolds and ports, etc.). What a flow bench reveals is how much flow energy a head will dissipate because of it's design and construction. At a standard pressure differential, a higher flowing head robs less energy from flow and thus, has less fluid friction forces restricting flow in the head -- you can deduce then, that there is less frictional resistance in the higher flowing head.

Now, why don't we look at an operating engine, not in steady state, and with valve openings and closings. Since you're interrupting and halting flow with valves, you must have to accelerate air through your head once you valves open, correct? Accelerating fluids in the presence of frictional forces requires the engine to expend more power on it's induction cycle, reducing it's efficiency and ultimate power output. Hence, the head that flows more on a flowbench has less frictional resistance, and thus will be more efficient and prone to making power under actual operating conditions.

Use of flowbenches at standard conditions is a great way to compare different heads, and the reduction in losses you develop by upgrading your valvetrain.

Although I'm not currently an engineering major, I have a decent grasp of fluid mechanics as I use it on a daily basis. I work in the pool and spa industry and am quite familiar with the principals behind the behavior of water or gas traveling through a fixed container. The problem with a flow bench is that if the results of the flow bench are the only consideration taken into account, then all "well designed motors" would run hogged out ports, with 2 humongous valves, just like most of the Nascar motors do.

Here is something that will make you think a little. I think that we could both agree that sport bikes have some of the highest power to displacement ratios for naturally aspirated motors. Over the course of the last 15-20 years look at the average port diameter on sport bike heads. What you will find is that they have gradually DECREASED the port diameter. I can also tell you that in comparison to straight flow rates on a flow bench, they will actually flow less. But how is it possible to flow less and make more power? Yes, the engine designs in general play a part, but not as much. In fact, what you will often find is that many people who build sport bikes professionally often decrease the stock port size. All of these modifications would make the head look like it should loose power if performed on the basis of the changes noted on the bench. The main problem with a flow bench, and the point that the TMS was making is that you are trying to infer the performance of the head using a device that doesn't in any way, simulate what's actually going on inside the motor. Port velocities, cam timing, valve overlap, reversion, intake and exhaust pulses, and many other variables AREN'T represented on a flow bench. Important variables that could potentially be more important that the information provided by a flow bench. It's not that a flow bench is a poor tool. It's a great tool, it's just not THE tool. It only looks at one aspect of the head.

Firstly, you reduce both the mass and rotational moment of inertia of your camshaft in the SR head. Since there are fewer lobes, there is less mass and it is more centralized around the rotational axis of the motor, allowing the camshaft to accelerate more quickly and with less resistance.

Additionally, with the SR's actuation design, there is less friction than in the CA18 head. With only one friction surface between cam and rocker for two valves, you've halved your friction surface, and thereby reduced frictional forces and head/cam oiling requirements.

While SR20s may have more reciprocating valvetrain mass than CA18s, they more than make up for it by the inherent ability of a rocker arm setup to run higher lift profiles, and more aggressive valve opening profiles. With a bucket-tappet setup, you find a limit when your valve ramp up is so steep that you essentially start slapping your cam opening face against your valve bucket. Also, your off-axis (sideways) loadings are much larger in cam on bucket systems than in rocker systems, increasing friction and wear between your valve stem and valve guides.

Although what you're saying sounds good, you're not backing it up with any numerical evidence. Have you weighed and compared the masses of the two cams? A longer duration, slower ramped, higher lift cam will have a HIGHER moment of inertia due to the greater amount of mass that is being moved around the axis. Also, have you measured to total contact area of the two cam designs? What numerical evidence do you have to support your claim that the friction is less in the SR head? Have you seen the width of a CA cam lobed compared to that of an SR cam lobe? I would venture to guess that it has at least the same, if not more surface area per cylinder than the CA. Once again, what numerical evidence do you have to support the statement that the greater contact area of the bucket lifter negates the gains provided by direct cam actuation as opposed to "lower contact area", levered rocker arm design? I don't disagree with your concepts, I disagree with you trying to make factual statements with no supporting (numerical) evidence.

Oh boy, street racing sure gives you some sweet credentials on engine design, right? By the way, thanks once again for attempting to make an argument with no numbers or design analysis to support your claim.

There is no better test to dictate an engines performance, than how it performs. If you want to look down on street racing fine. But if you build a motor and I build a motor and yours looks better on paper and mine goes faster, doesn't that mean I still win?

Stop being a hypocrite, you berate him for not supporting his arguments, yet you do the same. This thread was started as a means to vent being "discriminated against" by the ever popular, bandwagon, SR crowd. Sure it's a great motor and has it's merits. The same can be said for the CA. It's also true that the SR has got it's downfalls, and so does the CA. This topic has been beaten so many times is makes me ill to think about having another argument about it.

Nissan never build a CA20DET. They never built a high intake angle, 4 port head for it. They never gave the CA a decent sized turbo from the factory. With out these things all you have is some crap that you read out of a text book. You can theorize which motor will do better, but at the end of the day there is no way to compare apples to apples, and with out that it's all just speculation.

[themadscientist]

So why exactly are you here? What is your purpose in posting in this thread? What do you hope to achieve?

Do you honestly think that you're going to come in here touting a degree that you don't have yet and show us all the error of our ways? Enlighten us to the engineering marvel of the SR? Do you expect us to thank and praise your for your much desired knowledge?

You speak of having the desire to have a level headed legitimate discussion covering the various differences and pro's and con's of the various motors, but aren't able due to TMS's "condescending" post. Yet from my view you are the one that introduced yourself into this thread with condescension.

Although I'm not currently an engineering major, I have a decent grasp of fluid mechanics as I use it on a daily basis. I work in the pool and spa industry and am quite familiar with the principals behind the behavior or water or gas traveling through a fixed container. The problem with a flow bench is that if the results of the flow bench are the only consideration taken into account, then all "well designed motors" would run hogged out ports, with 2 humongous valves, just like most of the Nascar motors do.

Here is something that will make you think a little. I think that we could both agree that sport bikes have some of the highest power to displacement ratios for naturally aspirated motors. Over the course of the last 15-20 years look at the average port diameter or sport bike heads. What you will find is that they have gradually DECREASED the port diameter. I can also tell you that in comparison to straight flow rates on a flow bench, they will actually flow less. But how is it possible to flow less and make more power? Yes, the engine designs in general play a part, but not as much. In fact, what you will often find is that many people who build sport bikes professionally often decrease the stock port size. All of these modifications would make the head look like it should loose power if performed on the basis of the changes noted on the bench. The main problem with a flow bench, and the point that the TMS was making is that you are trying to infer the performance of the head using a device that doesn't in any way, simulate what's actually going on inside the motor. Port velocities, cam timing, valve overlap, reversion, intake and exhaust pulses, and many other variables AREN'T represented on a flow bench. Important variables that could potentially be more important that the information provided by a flow bench. It's not that a flow bench is a poor tool. It's a great tool, it's just not THE tool. It only looks at one aspect of the head.

Although what you're saying sounds good, you're not backing it up with any numerical evidence. have you weighed and compared the masses of the two cams? A longer duration, slower ramped, higher lift cam will have a HIGHER moment of inertia due to the greater amount of mass that is being moved around the axis. Also, have you measured to total contact area of the two cam designs? What numerical evidence do you have to support your claim that the friction is less in the SR head? Have you seen the width of a CA cam lobed compared to that of an SR cam lobe? I would venture to guess that it has at least the same, if not more surface area per cylinder than the CA. Once again, what numerical evidence do you have to support the statement that the greater contact area of the bucket lifter negates the gains provided by direct cam actuation as opposed to "lower contact area", levered rocker arm design? I don't disagree with your concepts, I disagree with you trying to make factual statements with no supporting (numerical) evidence.

There is no better test to dictate an engines performance, than how it performs. If you want to look down on street racing fine. But if you build a motor and I build a motor and yours looks better on paper and mine goes faster, doesn't that mean I still win?

Stop being a hypocrite, you berate him for not supporting his arguments, yet you do the same. This thread was started as a means to vent being "discriminated against" by the ever popular, bandwagon, SR crowd. Sure it's a great motor and has it's merits. The same can be said for the CA. It's also true that the SR has got it's downfalls, and so does the CA. This topic has been beaten so many times is makes me ill to think about having another argument about it.

Nissan never build a CA20DET. They never built a high, 4 port head for it. They never gave the CA a decent sized turbo from the factory. With out these things all you have is some crap that you read out of a text book. You can theorize which motor will do better, but at the end of the day there is no way to compare apples to apples, and with out that it's all just speculation.

Daym! check please.

[davidricardo86]

Wow! Thank God i became a CA guy! jk Some people take it to another level. Just tune your damn engine and back it up on the track with some driving. In the end, none of this is important but we do it cause its fun and it makes us feel good.

I dont really care if my CA is "crappy" when compared to (insert other engine here)? I dont have a degree in anything yet, im not a rocket scientist, and im only 20 years young and taking automotive classes at my community college, learning as much as i can. It's something i like and will continue for many years to come. I'm tuning this motor and i wouldnt change anything about it. Except more money, prats, and time. Maybe later i can have the opportunity to tune an SR,KA,RB,?! Hopefully. As long as im tuning something and still driving, im happy.

Some of the best arguements ive read from people on forums like these. Good information nonetheless! math...

[AmoebAssassin]

Reading is fundamental, try it again. You do exactly what you would denounce me for. Hipocracy is unattractive.

I fail to see how I am doing what I am "denouncing you for." I came to this thread asking anyone to please verify the hearsay that so many CA18 guys use to tout their own engines or scowl at others using their "underdog" engine choice, and so far nobody has done it satisfactorily.

If you're looking for numbers from me, I'm sorry, I don't have the time or resources right now to take apart and quantify my daily driver's motor, sorry. However, the difference is at least I brought known theories to this discussion -- most of you have brought nothing but things you've heard from your friend's friend on the internet.

Quote »Apparently you couldn't relate to them in second grade, nor now. Congratulations on your schooling, it means you read books. I read books too. I know too many people in too many diverse feilds who hide behind a diploma but can't do **** to back it up. I see "certified technicians" do dumb **** all the time. It doesn't mean a thing to me.

Again you failed to read. Better learn how I assume they still test you on things before they give you sheepskin. The steady state is in reference to the flowbench not the cam. Try again.[/quote]Okay, so treat the engine as an unsteady state machine only when it's convenient for your argument. Fair enough, right?

Schooling doesn't mean I've read books. Everyone reads books. People with good educations, however, understand books.

Quote »That's a fun one, I'll play along. All I have is a kitchen scale but I will go home tonight and weigh a CA cam, you weigh an SR one and we will see what we get. We have no way to measure moment of inertia here though but I know of the phenmenon of which you speak. Could we measure it I may have to award you a half point. The CA cams have narrower lobes compared to the SR though, it is tough to say which has more rotational mass, they would likely score very closely to each other on that.[/quote]I would actually really, really love to do this! At this current point in time, though, I cannot dismantle my daily driver. I will ask my friends to see if they have any spares but it is very unlikely. In either case, I will likely be getting newer cams this summer, so if this argument smolders on that long, I'll gladly run some analysis on my SR cams before I sell em off.

Quote »Now that is a solid point and worth mention, you definately earned that one. [/quote]Thanks

Quote »In general theory possibly but in actual use the SR ehxibits pronounced valve guide wear vs the CA and RB which are cam on bucket. This means more friction which will likely bring you back a step from the gain you made above. It may be the angle that the valve is on the SR, it may not be an all-the-time occurance with the fulcrum type valvetrain but it happens here.[/quote]I actually have not heard of this occurrence in SR's -- could you please divulge your source? The rocker arm will absorb the horizontal frictional loadings of the camshaft, whereas on the CA18 the horizontal force is transferred directly to the lifter and in turn the valve.

If you're not BSing me and this wear condition does exist in SRs, it's more likely a valve actuation angle issue than anything else -- this is unlikely, as the actuation angle is very close to 180 degrees, and the amount of side loading a rocker transfers to it's valve is traditionally very low. Perhaps the same you've seen was due to under-oiling or improper engine care. Regardless, I have not heard of this happening and would like to see any valve guide wear pictures if you have any.

Quote »It don't take a degree to see what is out there. The CA was on par with it's competion at the time in all design features, the SR is retro. Sorry if the dumb guy who doesn't kiss your *** because you read a textbook and think you have all the answers won't take the opinion based on what classes you took.[/quote]It doesn't take a degree to see what's out there, but it sure helps to have a firm engineering background from which you can make qualified comments, rather than backyard speculation. I don't have all the answers, nor was I claiming to have them. I merely came here to ask this forum to prove what everyone has been claiming sans evidence on the internet. It's not a problem of me having all the answers, its about the CA camp having little to none.

The only difference of arguable significance between the SR and CA is the valve actuation mechanism -- and cam-on-bucket design had been around for a good while before the CA18. Can you tell me any other "cutting edge" technology that's on CA18s? Cross flow heads and piston oil cooling come to mind, but again, these technologies have been around before the CA18. Same with EFI, etc. Please tell me what was so cutting edge about the CA18?

Quote »I never said the pushrod was bad, just not as good. Man you don't read at all do you? SOHC motors suffer the same problem regarding independent tuning of exhuast and intake timing, not a pushrod only issue. [/quote]Yes, I knew that, thanks. Mentioning SOHC motors is extraneous information and not pertinent to our argument at the moment. "Not as good" is purely subjective. Just as is said, what works on paper doesnt matter if it doesn't work in real life, right? Well rocker arms and pushrods may be ugly on paper, but they're working for a number of different engine designs, and they have been working well for some time now.

Quote »Adding parts when it is unnecesary of course. Were the pushrods to go away the motor would likely do better.[/quote]Without pushrods, the motor would not be able to open it's valves!

Quote »Let's see You have a 5.7 liter motor making 500hp (does math, curses himself for not getting that engineering degree so he could be all self-impressed like somebody) That's 87.71 hp per liter. Now somebody find me some particulars on it, compression ratio etc because here is what I put up against it the weak, pathetic old CA18DE(no turbo).1.8 liters making 150hp, (help me dude the math just hurts my highschool-educated brain and you are so smart) 83.33 hp per liter. This is in 1989 with 9.5:1 compression and grandma camshafts compared to the vette.

Now, I won't race the vette, it's more powerful and I wouldn't have a chance. Pound for pound though it ain't showing me much over my old CA. I am 34 by the way, don't age me and I do occasionally streetrace. Oh wait, that's one of those things where you think you are better than me again. Tell yourself whatever you need to to feel good about yourself. You read, I read, you talk, I do.So what is so great about the vette motor? That's the best they can do in this day and age? I wouldn't brag too much about that, it's embarassing when taken into context. Just for ****s let me give you the SR20DE (S13 model, I am pretty sure the later models had a bit more but this is era-correct and NA because I want to compare apples to apples) 160HP at 2 liters (help me einstein how much is that?) Yeah 80hp per liter, huh? How could that be? the SR is king! it has this nostalgic valvetrain that pwns the CA but pound for pound makes less power, dumb guy confused.[/quote]Bravo, the same people chiding me for bringing theory into an argument, and for focusing too strictly on "my books" have started using random dimensional analysis figures in some attempt to prove a point.

Ah, HP/L arguments -- the consolation prize for the man who can't make actual power. The funny part is, I bet 99% of the people reading this thread right now have made fun of honda tuners for using HP/L arguments in the past.

Why don't you please make HP/mass arguments. That's a more solid indicator of performance. And yes, go ahead and hate on LSx engines, knowing that they're not more than 100lbs more massive than your CA18 but make more than double the power, stock, and equally as reliably.

Quote »The only way to truly see what the head will do is to put it into operation in the real world. You are measuring a situation the engine will never see I suppose you would bore a block without a torque plate as well. It measures perfect sitting there on the floor smart guy number one, well smart guy number 2 lets put it together then. The head doesn't live on a vacuum table, it lives on a engine with all types of variables you have removed so you can say "well this one flows more air in the completely unrealistic arrangement than the other one so it must be better". This would be like religiously watching an air/fuel meter and using that as the only guideline and not adjusting it to make peak power in the range the motor will be living in. The dyno is where you tune, with the motor operating in the state it will live in.[/quote]It also seems as though you didn't read my previous post at all about why flow bench numbers can be used for head comparisons.

Let me remind you that nobody is using flowbench numbers in energy equations to calculate engine power. Flowbenching is a comparitive study, not an absolute one.

Oh, and by the way -- Isolating variables for analysis is called the scientific method. If you want to **** on that, you're going to have to go up against the foundations of science itself. Controlling the environment in which something operates to analyze its performance, or facilitate the study of its operation is an entirely acceptable practice, and has been so since the renaissance.

I'd also thank you not to presume as to what I would or would not do, thank you.

Quote »I think my posts in this thread say all I need, yours speak for you as well. I have been respectful when it was called for (everybody else and to your engine by the way) and firm when requested by the others conduct (you). Don't get butthurt. If you read you will see I don't hate on the SR but I am brutally honest about it and I am not afraid to turn that lens inward to the CA. I think you will find I am not an SR hater. I don't really hate any engine, well ok that 1.9 Opel motor was a ***** but that was because the timing mark was on the damned flywheel. [/quote]

Me, butthurt? Funny how I'm the one butthurt, when I made one post and this whole CA18 forum has got their panties in a bunch.

You will also find that I'm not a CA18 hater, by the way, and actually considered one for my chassis for a long, long time.

[AmoebAssassin]

So why exactly are you here? What is your purpose in posting in this thread? What do you hope to achieve?

See above post. I want someone to provide factual evidence for the claims you've all been making for some time now.

Quote »Do you honestly think that you're going to come in here touting a degree that you don't have yet and show us all the error of our ways? Enlighten us to the engineering marvel of the SR? Do you expect us to thank and praise your for your much desired knowledge? [/quote]No, and you're hanging on the slightest tidbits and blowing them out of proportion. I mentioned my degree once, to let TMS know that I'm not some stupid kid on the internet. YOU'RE the one who's making it seem like I'm trying to be your savior.

The SR is not an engineering marvel, and neither is the CA18. Stop treating it as such.

Quote »You speak of having the desire to have a level headed legitimate discussion covering the various differences and pro's and con's of the various motors, but aren't able due to TMS's "condescending" post. Yet from my view you are the one that introduced yourself into this thread with condescension. [/quote]Well you know the saying, opinions are like ***holes? I don't find it particularly worthwhile to argue about how you feel about me.

Quote »Although I'm not currently an engineering major, I have a decent grasp of fluid mechanics as I use it on a daily basis. I work in the pool and spa industry and am quite familiar with the principals behind the behavior of water or gas traveling through a fixed container. The problem with a flow bench is that if the results of the flow bench are the only consideration taken into account, then all "well designed motors" would run hogged out ports, with 2 humongous valves, just like most of the Nascar motors do. [/quote]No, motors designed to operate within a narrow RPM range with no consideration of powerband design (fuel atomization, intake velocities, runner lenth tuning using resonance, etc.) would use the head design you've mentioned. Oh wait, just like nascar - where the engines only operate at a very narrow RPM range and are not expected to perform outside said envelope.

Quote »Here is something that will make you think a little. I think that we could both agree that sport bikes have some of the highest power to displacement ratios for naturally aspirated motors. Over the course of the last 15-20 years look at the average port diameter on sport bike heads. What you will find is that they have gradually DECREASED the port diameter. I can also tell you that in comparison to straight flow rates on a flow bench, they will actually flow less. But how is it possible to flow less and make more power? Yes, the engine designs in general play a part, but not as much. In fact, what you will often find is that many people who build sport bikes professionally often decrease the stock port size. All of these modifications would make the head look like it should loose power if performed on the basis of the changes noted on the bench. The main problem with a flow bench, and the point that the TMS was making is that you are trying to infer the performance of the head using a device that doesn't in any way, simulate what's actually going on inside the motor. Port velocities, cam timing, valve overlap, reversion, intake and exhaust pulses, and many other variables AREN'T represented on a flow bench. Important variables that could potentially be more important that the information provided by a flow bench. It's not that a flow bench is a poor tool. It's a great tool, it's just not THE tool. It only looks at one aspect of the head.[/quote]The flowbench is used not to measure, but compare. Flow benches are used to qualify the frictional losses in a head. This is a major design consideration, and believe it or not, it is one of the most important aspects of head design.

What you have to understand about sport bikes is that even though they are very high revving, their volumetric flow rate is still very low compared to automobile engines. Therefore, port sizes can be reduced to increase intake tract velocities, and promote better atomization - this leads to more even combustion, and more power. This is a very specialized case, however, and should not be applied to automobile engine analysis.

Quote »Although what you're saying sounds good, you're not backing it up with any numerical evidence. Have you weighed and compared the masses of the two cams? A longer duration, slower ramped, higher lift cam will have a HIGHER moment of inertia due to the greater amount of mass that is being moved around the axis. Also, have you measured to total contact area of the two cam designs? What numerical evidence do you have to support your claim that the friction is less in the SR head? Have you seen the width of a CA cam lobed compared to that of an SR cam lobe? I would venture to guess that it has at least the same, if not more surface area per cylinder than the CA. Once again, what numerical evidence do you have to support the statement that the greater contact area of the bucket lifter negates the gains provided by direct cam actuation as opposed to "lower contact area", levered rocker arm design? I don't disagree with your concepts, I disagree with you trying to make factual statements with no supporting (numerical) evidence. [/quote]I do agree with you wholeheartedly about my lack of numerical evidence, but the burden of proof is NOT on me in this thread. I've not once stated intent to prove the SR is better than the CA18, and you can re-read my posts if you don't believe me.

I've watched as CA18 owners have grown smug and become more comfortable denouncing SR engines as cheap or poorly designed. I'm here to ask you to prove it, and none of you have given ME any numbers. Nobody has given me production cost analysis, or any other numbers. The only one who has even attempted has been TMS.

Quote »There is no better test to dictate an engines performance, than how it performs. If you want to look down on street racing fine. But if you build a motor and I build a motor and yours looks better on paper and mine goes faster, doesn't that mean I still win? [/quote]Yes, it does, but thats not what I'm here to argue. By the way, if you feel that strongly about paper vs. performance, why are you letting your friends tout HP/L numbers?

[themadscientist]

I would actually really, really love to do this! At this current point in time, though, I cannot dismantle my daily driver. I will ask my friends to see if they have any spares but it is very unlikely. In either case, I will likely be getting newer cams this summer, so if this argument smolders on that long, I'll gladly run some analysis on my SR cams before I sell em off.

I think any SR and CA cam would be good enough for comparison. If I can find one on my end I can at minimum get basic weights of the two.

Thanks

You earned that, I don't give anybody anything, it was a good point and if I can find an SR cam I can measure the lobe width. The theory is sound but the important part is getting the measurement to plug in.

I actually have not heard of this occurrence in SR's -- could you please divulge your source? The rocker arm will absorb the horizontal frictional loadings of the camshaft, whereas on the CA18 the horizontal force is transferred directly to the lifter and in turn the valve.

If you're not BSing me and this wear condition does exist in SRs, it's more likely a valve actuation angle issue than anything else -- this is unlikely, as the actuation angle is very close to 180 degrees, and the amount of side loading a rocker transfers to it's valve is traditionally very low. Perhaps the same you've seen was due to under-oiling or improper engine care. Regardless, I have not heard of this happening and would like to see any valve guide wear pictures if you have any.

It has been evident in SRs that I have seen torn down. It appears to me as if the rocker is shifting around as it works. That's why I wonder if it just an SR thing and not necessarily a design thing in general. Could be an oil change thing, Japanese dudes don't do that as much as they should and most of the popped SRs I see have evidence of shoddy maintenance. Couple this with the lack of good machine shops around here (I was told by every shop I approached they were unable to even change valveguides) and I wonder how many tore up guides are running around in "rebuilt" engines. You should have seen the look on the guys face when I said things like "dynamic balance" and "torque plate". I miss the states sometimes

It doesn't take a degree to see what's out there, but it sure helps to have a firm engineering background from which you can make qualified comments, rather than backyard speculation. I don't have all the answers, nor was I claiming to have them. I merely came here to ask this forum to prove what everyone has been claiming sans evidence on the internet. It's not a problem of me having all the answers, its about the CA camp having little to none.

I think both camps have silly battle crys that embarrass the more moderate enthusiasts. If I have to hear one more "it's 2/3s of an RB" I might have to smack someone.

The only difference of arguable significance between the SR and CA is the valve actuation mechanism -- and cam-on-bucket design had been around for a good while before the CA18. Can you tell me any other "cutting edge" technology that's on CA18s? Cross flow heads and piston oil cooling come to mind, but again, these technologies have been around before the CA18. Same with EFI, etc. Please tell me what was so cutting edge about the CA18?

I should have said up-to-date, I get verbose. Nobody's street engine has "cutting edge" anything. By the time new advances trickle down to the consumer it is already accepted standard. I maintain though that the SR is a throwback to older technology where the head is concerned. The whole chain vs belt debate is not one I involve myself in. I like belt but I have no bad things to say about chain either. Chain works in my L and my FJ (well, not so good in my FJ, ****ing upper tensioner) but I prefer the belt. I change mine regularly though so breakage is not somethin I worry about.

Yes, I knew that, thanks. Mentioning SOHC motors is extraneous information and not pertinent to our argument at the moment. "Not as good" is purely subjective. Just as is said, what works on paper doesnt matter if it doesn't work in real life, right? Well rocker arms and pushrods may be ugly on paper, but they're working for a number of different engine designs, and they have been working well for some time now.

Pushrods get it done, no doubt, please don't think I harbor some disdain for them, I don't. Same goes with the SR type rocker arm, the L uses a similar arrangement. I just hold to the KISS principle and the more parts involved the more it worries me.

Without pushrods, the motor would not be able to open it's valves!

I knew you would do that, boo hiss, I fed you that one

Ah, HP/L arguments -- the consolation prize for the man who can't make actual power. The funny part is, I bet 99% of the people reading this thread right now have made fun of honda tuners for using HP/L arguments in the past.

When dealing with dissimilar motors the only way to quantitatively compare them for the efficiancy and functionality of their designs you must find a common denominator.I clown on those Honda guys too. I am not talking about the total HP but rather the power per liter. The argument for total HP is easy and short, who got more? I think the vette is safe from most four bangers.I can imagine your amusement, when a Honda guy would get uppity about their whatever horsepower per liter I would remind them that while good, they only had 1.6-1.8 of them. We are discussing design so it is relevant, were we discussing maximum power output the motors size and displacement would indeed be irrelevant.

Why don't you please make HP/mass arguments. That's a more solid indicator of performance. And yes, go ahead and hate on LSx engines, knowing that they're not more than 100lbs more massive than your CA18 but make more than double the power, stock, and equally as reliably.

Because we are not talking about total hp but rather the functionality of the various designs and their contribution. I'm not hating on the V8, I am from musclecar roots, I love a lopey V8. Imagine though if they built a big iron american motor that put out the same power per liter or cube if you will as both yours and mine do. I think you would agree 600hp is better than 500, I'd take it!

It also seems as though you didn't read my previous post at all about why flow bench numbers can be used for head comparisons.

Let me remind you that nobody is using flowbench numbers in energy equations to calculate engine power. Flowbenching is a comparitive study, not an absolute one.

Oh, and by the way -- Isolating variables for analysis is called the scientific method. If you want to **** on that, you're going to have to go up against the foundations of science itself. Controlling the environment in which something operates to analyze its performance, or facilitate the study of its operation is an entirely acceptable practice, and has been so since the renaissance.

The scientific method would work on anything. You would be able to tell the difference on the flowbench between a ported and unported head. The sticking point I keep comeing back to though is the engine does not breath like a flowbench when it operates so while you have collected consistent comparative data it is useless because it simulates a situation the part in question will never experience.Now an engine on a dyno will gather comparative data that is applicable to the task because it is operating as it is supposed to with all variables present. No flowbench can simulate this and no stack of formulas will completely mimic real world running so it is useless.

Me, butthurt? Funny how I'm the one butthurt, when I made one post and this whole CA18 forum has got their panties in a bunch.

You will also find that I'm not a CA18 hater, by the way, and actually considered one for my chassis for a long, long time.

Well we have two self acknowledged non-haters, sounds win-win to me. I think most CA guys are shoot first ask questions later, true enough. In their defense they have years of disrespect from the the "other side" fueling it. Not nesessarily right but it is true.

[Ca_laurier]

I smell a calgary ca18 owners meet.....

hehehehe

Pm me calgary ca owners. Would love to meet up

woot Calgary, now if only my Ca wasnt parked....damn

Thats why the internet is your friend when you own a CA.

Edit: I see your form Calgary also......GO FLAMES!!!

holy crap, i thought i was the only ca guy from calgary on here

i have been supporting the ca since 2003 (when i bought my first one) and damn have i taken a beating from people. but still when people were in my old ca (forged pistons, connecting rods, s15 t28, longer gears in the transmission) they were all impressed with how it moved

[dash]

Who pi55ed on the hornets' nest ? SR guns a'blaze.... hehemy comments were focused on the ca18 pros/cons.... it can get by on its own merits.

madscientistCA18 intake butterflys, way the motor 'leans', identical positioning of of belt driven accessories, etc... dam near a rwd 4AGE twin.Since you're in denial about the striking similarities, go ahead and explain this 'major groundbreaking' design difference that elevates our ca18 cylinder head beyond a 4age.What 'real world' advantage does CA head have over a 4age head ? Don't tell me liftersNow specify exactly how ca18 'became cutting edge' vs a 1984 4ag head... or the CA motor is, vs say a 1986 7mgte.