Rebuild or sr..........yuck

[JesusLikesKFC]

got a 91 ka and it despretly needs a rebiuld only i have one problem, since last week i have no house or no garage. Im in the newyork area and alot of shops really dont hav much under their belt and like to charge up the a$$. Anyway heres the thought, should i cough up the cash and go for the full rebuild or go for a sr....... personally i lov my ka beast and keep in mind i have a limit of dough. Any info on shops or online rebuilt ka's would b awsome.

[tonynalli]

a built ka will be far better then a stock sr. you only need to purchase new pistons and rings as far as that it concerned. now when you say that it desperatly needs a rebuild what do you mean. what wrong wit h it?

[JesusLikesKFC]

well it really doesnt need a whole rebuilt, jusr top end so it can handle some boost in the very near future. but as of now valves are sticking, bad compression due to bad compression and guncted up valves. just really perfer having the ka rathr than a lil 2 sr

[Bigvinnie]

got a 91 ka and it despretly needs a rebiuld only i have one problem, since last week i have no house or no garage. Im in the newyork area and alot of shops really dont hav much under their belt and like to charge up the a$$. Anyway heres the thought, should i cough up the cash and go for the full rebuild or go for a sr....... personally i lov my ka beast and keep in mind i have a limit of dough. Any info on shops or online rebuilt ka's would b awsome.

I would go with a rebuilt KA. Make shure that the rods are forged so that you can get an 8000RPM redline out of the 2.4litre. Eagle and wiseco are sold all over the place with the ka rods. Since you have a 91 that means you have the DE. By installing the 1990-92 SOHC pistons you can raise the compression to the KA to about 10.7:1 CR that will defenitely raise you top end power and redline as well. To make shure your valvetrain won't blow get titanium retainers and springs. CA and KA valvetrains are compatible so what ever shop you can get it from for cheaper would be fine.With an ECU upgrade and the removal of the butterfly's you will make alot more HP.

[rod0921]

he said he wants it ready for boost, i think the last think hed want is to raise the CR

[Bigvinnie]

Missed that part, but if thats the case just leave it at it's stock CR.

[HolyShiznit]

Big Vinnie what is the point of suggesting to him to rev to 8,000 RPM? Part of the fun of a KA is area under the curve, stock KA's power levels drop off after 6k anyways. Unless he has the Crower V2, or V3's both of which are not available he won't be holding power out to that level anyways. Stock redline will be more than fine, no point in revving out. This isn't a full crazy drag car.

[Bigvinnie]

Big Vinnie what is the point of suggesting to him to rev to 8,000 RPM? Part of the fun of a KA is area under the curve, stock KA's power levels drop off after 6k anyways. Unless he has the Crower V2, or V3's both of which are not available he won't be holding power out to that level anyways. Stock redline will be more than fine, no point in revving out. This isn't a full crazy drag car.

Well me personally I would like a higher rev using longer lift and duration cams. If he was to stay the route of N/A and signicantly raised compression there would be more power to use in the power band upto atleast 7000RPM. Since he is going the route of F/I the turbo alone if boosted well will achieve power into the higher 7000RPM range.Thats why I stress the importance of forging the internalls, (especially the rods).As for myself my project on the way is that of most of those items stated including the 11.1:1 internals. An aluminum flywheel itself, will allow the KA to rev higher than it's 6000RPM peak potential. I know this I already have the aluminum flywheel, aluminum crank pulley, DC sports header full exhaust, intake along with a few others. The KA becomes anemic in the 6000RPM range just because of all of the rotational mass it carries with it.I would say mostly to get the KA to high rev is mostly a precautionary measure, it doesn't take alot of modifying to get it to peak in the 7000RPM range, especially if F/I or more aggresive cams are applied, lets not forget that alot of people that go NOS would also like the safety limits of having that rev at 8000RPM, rather than the stock rev limit of about 7200RPM.....

[Florida240sx]

I know the basics of engine,But I'm no engine builder. But never heard that by raising your CR you raise your redline. Also isn't the redlien determined by the length of travel the piston must go multiplied by it's size?Don't see how a flywheel will increase your redline.

[Bigvinnie]

I know the basics of engine,But I'm no engine builder. But never heard that by raising your CR you raise your redline. Also isn't the redlien determined by the length of travel the piston must go multiplied by it's size?Don't see how a flywheel will increase your redline.

Increasing the CR increases your power band, compression, cylinder temps, and breathability of the engine (for N/A). The only way to increase the redline without bending a rod or screwing up the valve train is to use forged internals , and titanium retainers and springs.Put it like this, the KA with shot peened internals, (pistons and rods) already exceeds it's limitations at about 5700RPM. The piston at 89mm, with a 96mm stroke hits deck hiegth at 5000ft per minute. That already puts the valve train at risk as well as the shot peened steel. Nissan did a pretty good job designing the stock OEM shot peened rods, that help with the stock redline at about 7200RPM. The KA in stock trim wasn't ment to hold the 7200 redline for too long it will still blow the valve train, or bend a rod. Forging is a good insurance when bumping up your cr, or F/I, or NOS, or even using really agressive cams.For myself I like drifting more than doing 1/4mile times, so I can use that additional rev even if it's not at it's peak performance. 1/4 mile time being different as to where you would want to shift right at the peak of the power band not neccesarily the redline. It will allow me to drift without having to shift in the middle of a corner or turn. Inevitably a higher redline will also get you a higher top speed, enough said.....

[JesusLikesKFC]

just a thought, if i were to go the N/A route and sav some cash how would sohc pistons be in my 91? would it be streetable? because of higher CR wat is the min octane i can use...96 or lower? boosting my ka now is just noy realistic cause i gotta pay off college and im kinda tight on cash but im still gonna treat my ka right. ive owned my 91 since january 05 and since then hav been adding all the bolt ons like intake( filter cone, no sence in paying 200 for bent piping for intak) exhaust, no cat, ignition, crankpulley, edmissions plugging, dropped ac, all the ussaul stuff. anyways need to find a good shop for a quality rebiuld in NY or round there, along with a build maybee sohc pistons cause im still not sure bout daily use and cost of ga$, cams new valves and all those goodies after a bunch of research. Feel free to thro out any ideas/experience about building a n/a monster.....on a budget. Links to sites would be cool too. thanx

[Bigvinnie]

just a thought, if i were to go the N/A route and sav some cash how would sohc pistons be in my 91? would it be streetable? because of higher CR wat is the min octane i can use...96 or lower? boosting my ka now is just noy realistic cause i gotta pay off college and im kinda tight on cash but im still gonna treat my ka right. ive owned my 91 since january 05 and since then hav been adding all the bolt ons like intake( filter cone, no sence in paying 200 for bent piping for intak) exhaust, no cat, ignition, crankpulley, edmissions plugging, dropped ac, all the ussaul stuff. anyways need to find a good shop for a quality rebiuld in NY or round there, along with a build maybee sohc pistons cause im still not sure bout daily use and cost of ga$, cams new valves and all those goodies after a bunch of research. Feel free to thro out any ideas/experience about building a n/a monster.....on a budget. Links to sites would be cool too. thanx

SOHC pistons are streetable@89mm I think it has a 11.1:[email protected] I think it's 10.7:1@90mm I think it's 10.3:1each is from stock to the adjusted bore sizes for rebuild. If you use the SOHC pistons you will need to get a forged rod kit from the 89-90 SOHC engines, it's just the way the pin assembly comes together. With a proper ecu tune you can get it to run on 91 octane.

[HolyShiznit]

Still don't understand where the added HP from FI is going to come from in the top end. I have had my car turbocharged for 3 years under numerous boost levels and I can tell you that without cams, regardless of what turbo and all that stuff you ain't gonna make **** for power past 6500. Just not possible.

Also the stock bottom end can hold a lot. Mine did forever and a day. However I don't understand why you would want an 8grand redline on a car that is already stressing the rods (any rods) at those speeds.

[Bigvinnie]

It's not any rods. I'm not turbo charged and I know even for a stock N/A what it takes, been working with them for a while. Jeff240sx claims 8000RPM is where he is making power so take it up with him, we had this in the dampener debate, so don't make me quote from fresh alloy. As for me the 8000rpm is what I need so I don't shift as often. It's plain and simple common logic when you use forged internals. This isn't a debate, just common logic... I even mentioned using aggresive cam lobe and duration.....Stronger steel gets the job done..........For F/I, let me put it bluntly...... You must be shifting early or you really havent hit the dyno, you defenitely have power in the 7000RPM range that your not using. Instead of bickering show me a dyno, or shut the FU$K up.......Please when you do show a dyno please mention what type of cams your using as well as the internals and there strength, since you want to get so personal with this debate.....
Modified by Bigvinnie at 2:30 AM 8/28/2005

[InsanityInc]

SOHC pistons are streetable@89mm I think it has a 11.1:[email protected] I think it's 10.7:1@90mm I think it's 10.3:1each is from stock to the adjusted bore sizes for rebuild. If you use the SOHC pistons you will need to get a forged rod kit from the 89-90 SOHC engines, it's just the way the pin assembly comes together. With a proper ecu tune you can get it to run on 91 octane.

Increasing the bore increases your compression ratio because you're increasing the collapsable area of the cylinder, but leaving the space in the head the same.

[Bigvinnie]

Increasing the bore increases your compression ratio because you're increasing the collapsable area of the cylinder, but leaving the space in the head the same.

90-92 SOHC pistons have a .020 dropped dish piston volume, it actually decreases collapsable space. It would be true if you used the 89 raised dish volume .020, or even flat top pistons. I'm not shuure if I was 100% right with the drop dish volumes. It's not recomended to use the 89 pistons due to valve clearance issues.
Modified by Bigvinnie at 8:38 AM 8/28/2005

[InsanityInc]

Stock DOHC KA pistons have a larger dish, and no, boring it out does not decrease compression ratio with the same height piston, ever.

Compression ratio = (Cylinder Volume + Combustion Chamber Volume)/Combustion Chamber Volume

When you bore out an engine, Cylinder Volume goes up, but combustion chamber volume stays the same(within about .5cc, even if it's dished), meaning you get a higher compression ratio, end of story. Doesn't matter if your piston is shaped like a triangle or a bowl.

[HolyShiznit]

For F/I, let me put it bluntly...... You must be shifting early or you really havent hit the dyno, you defenitely have power in the 7000RPM range that your not using. Instead of bickering show me a dyno, or shut the FU$K up.......Please when you do show a dyno please mention what type of cams your using as well as the internals and there strength, since you want to get so personal with this debate.....

Ok you get mad and pissy when someone with more experience calls you on something, but I am getting personal...right. Please don't come on here with a pompous attitude, I rarely walk into the murkiness of the KA board preferring to stay in the KA-T section and KA-T.org.



There's your goddamn dyno of my car. I have a fully ported and polished head/intake manifold, they are ported all the way out to the gasket and then some, I have a equal length manifold, I have forged SuperTech 9:1 pistons, I have stock 93' cams. Notice that by redline I have fallen to near 300whp. That's bad. 6500 is where it really starts to nose dive.
Modified by HolyShiznit at 10:58 AM 8/28/2005

[Bigvinnie]

I have stock 93' cams. Modified by HolyShiznit at 10:58 AM 8/28/2005

There is your problem right there. Honestly it's a nice dyno, but you didn't pay attention to a word I said..... With much longer duration, and higher lift cams (aggressive cams) that power can easily be pulled into the 7000RPM range, the cams are the lungs of your engine (let your engine breath). When you go FI atleast use a stage 1 so you can properlly use your setup.Honestly nice setup, thanks for showing the dyno.

[HolyShiznit]

Stage 1 what? I have the Crower V3's on order for 6 months now, I will be the first person in the US to own them commercially. When they actually get blanks...

Other than the Crowers no cams have had dyno proven results. At least not turbo specific cams.

[Bigvinnie]

Other than the Crowers no cams have had dyno proven results. At least not turbo specific cams.

Well you can infact use the cam specs from the CA18det, before turbo charging became big for KA alot of boostheads took the specs and formatted it for KA. CA and KA share the same valvetrain. Alot of people would regrind the KA cams it's cheaper than buying new ones.HKS and Greddy have paper work full of dyno proven results. Phat KAT has also been getting into cam grinds.

[HolyShiznit]

HKS and Greddy do not make cams for the KA. PHATKA-T is not doing there own cam grinds, they received them from Crower.....which is where I ordered them. So I am stuck.

[Bigvinnie]

HKS and Greddy do not make cams for the KA. PHATKA-T is not doing there own cam grinds, they received them from Crower.....which is where I ordered them. So I am stuck.

You missed what I said Greddy and HKS make cams for the CA. The grind specs to the CA and KA are compatible to use they both use the same hydraulic bucket assembly valvetrain. CA cam specs are just regrinds for the KA cams...

[tonynalli]

doesnt jwt make cams?

[HolyShiznit]

Yes they do but there was been no dyno results that show they make that much power. Klattr has them on his KA-T and we both talked and we weren't too sure if they actualy made power either.

[S13Coupe]

Have you thought about PDM? They have cams for KA-T's.

http://www.pdm-racing.com/products/cam_corner.html

[HolyShiznit]

Once again, no dyno's to prove they actually make power. Crower sent Ivan 7 or 8 different sets of cams, only 2 made power. I worry that without actual testing or dyno numbers I could be buying something that doesn't do anything.

That's why KA guys should stick with PDM cams for NA applications (as they have actual numbers for their NA cams) or Crower's for the FI side of things.

[Bigvinnie]

These JWT cams are proven to make power. JWT Cams .390" lift 275 deg dur.http://www.240sxmotoring.com/19ni24ka43.html

[InsanityInc]

These JWT cams are proven to make power. JWT Cams .390" lift 275 deg dur.http://www.240sxmotoring.com/19ni24ka43.html

Well, that link doesn't have a dyno, meaning you have no way of knowing what the cams did. For all you know, he could just be running a far larger turbo.

Also, in lieu of buying new cams, you should be able to adjust your cams to get better performance for a turbocharged application. Basically, you want very little (possibly no) overlap, and a very late intake closing point, since the turbo is getting your intake velocities to be very high, it'll keep pressurizing the cylinder long into the compression stroke. So, basically you'll want to retard your intake cam probably about 10 degrees, if not more. Just nmake sure nothing is hitting the piston by rotating the crank a few full revolutions by hand before you try cranking it.

[HolyShiznit]

Thanks Insanity you are correct on all accounts. As I said before, people USE JWT cams but they don't have PROOF they make power, or even smooth out the power band. Most of the shifting of power bands I have seen have been more directly related to extremely hard to do(and time consuming) cam timing.