ok guys here it is proof

Post by **Rownan** » Tue Oct 28, 2003 8:55 pm

You realize with 11.7:1 compression you will not be able to run pump gas.

Just to share a little bit of knowledge with you, if you want 200rwhp on N/A, you would be smart to trash the 270cc injectors. They fall out of efficiency quickly above 190ish.

Post by **raging panda** » Tue Oct 28, 2003 8:55 pm

He said he already got it running and went around the block or something, I don't think he went out and got race gas to go around the block.

Post by **Rownan** » Tue Oct 28, 2003 8:55 pm

raging panda wrote:He said he already got it running and went around the block or something, I don't think he went out and got race gas to go around the block.

"running" means nothing. What kind of fuel management is this beast using?

Post by **deviousKA** » Tue Oct 28, 2003 8:55 pm

what are you talking fuel management? this is just a basic setup with around 11.5:1 cr, premium pump gas, base timing (possibly slightly advanced). This does not require any more than 93 octane. You will not need any type of alternate management unless you plan to run larger injectors, or tune some more out of the current 270's.

Post by **Rownan** » Tue Oct 28, 2003 8:55 pm

deviousKA wrote:what are you talking fuel management? this is just a basic setup with around 11.5:1 cr, premium pump gas, base timing (possibly slightly advanced). This does not require any more than 93 octane. You will not need any type of alternate management unless you plan to run larger injectors, or tune some more out of the current 270's.

The stock fuel curves are not even close to optimized running a stock engine, what makes you think they are good on an engine running 11.7:1 CR?

How long have YOU been running a setup like this?

Post by **deviousKA** » Tue Oct 28, 2003 8:55 pm

What are you trying to say? Any oem efi system can be improved upon (as far as performance is concerned), yes i agree. The stock eccs system on both dohc and sohc ka's is perfectly cabable of running decently with both stock and high compression ratios, detonation issues aside. High compression does not "require" any air/fuel tuning from stock configuration.

Post by **Rownan** » Tue Oct 28, 2003 8:55 pm

[quote=" deviousKA What are you trying to say? Any oem efi system can be improved upon (as far as performance is concerned), yes i agree. The stock eccs system on both dohc and sohc ka's is perfectly cabable of running decently with both stock and high compression ratios, detonation issues aside. High compression does not "require" any air/fuel tuning from stock configuration. [/quote]

Hahaha!

Post by **raging panda** » Tue Oct 28, 2003 8:55 pm

I don't understand what the problem is. Smug510 is running a high compression KA with pump gas and what was a stock injection system with the fuel pressure turned up. He dropped the 370s in because he didn't want that high a fuel pressure in his rail. I know that the engine hasn't been run hard yet, but with tuning I'm sure it will end up that way. But the OEM fuel system is holding up.

Post by **Rownan** » Tue Oct 28, 2003 8:55 pm

raging panda wrote:I don't understand what the problem is. Smug510 is running a high compression KA with pump gas and what was a stock injection system with the fuel pressure turned up. He dropped the 370s in because he didn't want that high a fuel pressure in his rail. I know that the engine hasn't been run hard yet, but with tuning I'm sure it will end up that way. But the OEM fuel system is holding up.

I'm not worried about the fuel system! I'm worried about the engine. I'm telling ya, he's gonna have serious issues unless he backs WAYYYYY off on the timing, even then he might run into problems.

I suggest calling jim wolf to get a second opinion. I can only speak as a tuner running an 11:1 KA. 11.7:1 on pump gas is crazy talk.

Post by **7thGear** » Tue Oct 28, 2003 8:55 pm

Rownan wrote:You realize with 11.7:1 compression you will not be able to run pump gas.

Just to share a little bit of knowledge with you, if you want 200rwhp on N/A, you would be smart to trash the 270cc injectors. They fall out of efficiency quickly above 190ish.

if hondas can run 12:1 on pump gas, i dont see why nissans cant do it either.

( here is just a sample of testamonials) http://www.honda-tech.com/zerothread?id=760148

Post by **Rownan** » Tue Oct 28, 2003 8:55 pm

7thGear wrote:if hondas can run 12:1 on pump gas, i dont see why nissans cant do it either.

( here is just a sample of testamonials) http://www.honda-tech.com/zerothread?id=760148

Right, cause honda engine = nissan engine. :rolleyes

Look, no one has to listen to me. Blow a hole in your piston for all I care.

Post by **McAdam** » Tue Oct 28, 2003 8:55 pm

and if they do, KA pistons are a dime a dozen. If the honda boys are running that high of compression, there is no reason why a nissan engine can't. The Hondas have crap for a rod/stroke ratio. thats not good for detonation resistance. the KA is actually a stock motor with a decent rod/stroke ratio. hell, if theres people running 11.3:1 on pump gas on an L28E with a non crossflow head and a crap combustion chamber, i am sure the KA is capable. on a side note,

devious>>>> I found a Z20S in a nissan pickup. we are picking this block up this weekend, plans are bore it to 90mm, use +1mm KA pistons, shave 2mm off the top, and run a KA24E head with mild porting for now, and see how it runs. then we'll swap over to the DE and see whats up. I do need some Z20E rods tho, no Z20E's in the yard, damn. any ideas?

McAdam

Post by **deviousKA** » Tue Oct 28, 2003 8:55 pm

Modern Honda engines can run a higher compression ratio due mainly to their combustion chamber and head design. Ka24de has a slight advantage of combustion chamber design (not just the extra valve) over the the ka24e. Basically this means detonation occurs at a higher compression ratio vs. the kaE.

it is impossible to run 11.7:1 compression in de without fly cut pistons. Most people think they are running higher than 11:1 compression ratio because the the ka24e pistons they are using "appear" to be flat top (there is acutally a ~2cc dish, roughly .020" lower than compression ht of piston). The high compression ka24e pistons actually have a positive dome volume of around 2cc's. These come in contact with valves in de if they are not flycut. - this is just some info i thought i would add.

Nice find McAdam, i found another myself. I can get the 152mm z20e rods if you need them, but i think you might want to try a different route so that you dont have to mill the piston tops. I also hear the z20e rods in particular are a bit weak, i have never inspected them personally tho. Why not go with a z22e rod? It doesnt give as nice of rod/stroke ratio, but would allow your ka pistons to work out nicely (these rods are a bit rare tho, the 149.5mm). I am using custom 150mm rods with my 88mm stroke. These use a smaller journal diameter as well.

you can always look into going with a slightly shorter rod, this opens up piston options a bit

Post by **McAdam** » Tue Oct 28, 2003 8:55 pm

I was looking at the Z22E rod. problem is that we are going to slap a KA24E head on it at first. and if we use a KA24E flat top, on a Z22E rod, then it gives us a -1mm deck height, that, combined with the HUGE combustion chamber volume of the E head will suck for a compression ratio, lol! but, now with early KA24E pistons in a +1mm overbore, with the slight dome, it shouldnt be too bad. plus I think I will have the head shaved .020" to give it a nice little bump. If you want some Z22E rods, there are 2 200sx's in the yard where I go. $10 for each piston/rod combo. I guess we can live with low compression for a while.

I was just planning on running the E head to make sure everything was looking good before we slap on the DE head. that, and the E head will be a bolt on affair, just using Z20S timing accessories. this will be going into a 1989 240sx hatch back. the person that I am doing this with wants something different. something not SR, lol and something cheap. so, this looks like a winner! plus, if all works out, I'll probably build one to toss in my spare 240sx hatch, lol

McAdam

p.s. are you going to get the block sonic checked? Id like to hear the results.

Post by **deviousKA** » Tue Oct 28, 2003 8:55 pm

well, there is always the good ol' vg rod. These rods with 86mm stroke and medium ht block, requires ~30.9 or so compression ht pistons. I can get forged 90.2mm pistons with this spec, but you will have to hone the rods to 22mm pin (easier if you use the vg full floating rods to start). With this you get a nice 1.8:1 rod/stroke ratio. This combo just happens to be one my future signature crate motors

I have a new order up for the pistons, i will have a couple sets in stock next week or so. They are probe srs forged

the 9.1:1 ka24e pistons dont really have a "dome" more of a step similar to that of the 8.6:1 dish, but in the other direction

You might want to grab the motor mounts off one of those 200sx's, they make it easier to fit z block in 240.

my current bored z20 block is assembled at the moment, next one i do i will have sonic tested.

Post by **McAdam** » Tue Oct 28, 2003 8:55 pm

doesn't the VG have a much thinner big end bearing that the L series motors? I had looked into using the VG rod on a L series 6 I was going to build and its a lot thinner than the L series rod. I'll have to look into to the probe pistons, aren't they hyper-eutectic(sp) or something like that? I had planned on grabbing the 200sx motor mounts and oil pan, as the truck is a 4x4. plus, I have to pull a Z22E motor out of the 200sx to get the rods! thanks again for the info! this will be fuuuuuuun!

McAdam

p.s. I would have loved to see the look on your machiists face when you brought the block in and said, "yeah, I'd like to have this overbored 5mm (.200 in)"

Post by **deviousKA** » Tue Oct 28, 2003 8:55 pm

eh, i must have had a brain fade last night or something, vg rod journals are thinner. I will have to look into that a little further later. The probe srs pistons are high quality forged, equal or better than ross forged.

hehe, yeah i get charged extra for wearing out his tooling.

Post by **nissanguy_24** » Tue Oct 28, 2003 8:55 pm

keep us all posted on this

Post by **ayjay** » Tue Oct 28, 2003 8:55 pm

holly **** guys, this thread is awesome... i'm really interested in doing this in the near future

got a couple questions though... got a 90 ka24e...

if i were to swap on a ka24de head, do the the pistons need to be "fly cut"? deviousKA you mentioned something about that, whereas smug510 didn't say it needed to be done... little confused...

also to what extent can the head be moddified? like i'm assuming titanium valve springs & retainers would be no problem, but what about more aggressive cams and 3 angle valve grinds and stuff?

thanks, i'm a little clueless when it comes to this stuff, but i wanna learn

Post by **cory2081** » Tue Oct 28, 2003 8:55 pm

This is a great thread. I've read most of it. You could also have bought a de and swapped your e pistons in it for higher compression. I'm sure everyone knows that though. So, what do you think your HP gains are??

Post by **Tastyratz** » Tue Oct 28, 2003 8:55 pm

ayjay, a 3 angle grind could do nothing but help, since valve clearance seems to be a concern. even if anything it shouldnt matter. valves and springs wont really make anything worse like you were assuming, unless you get oversized valves and that brings back up to the clearance problem. cams could actually be a problem depending on how much room to play with there is in there. what we really need is some math guru on the board who knows how to calculate all that stuff and put it out in black and white.

Post by **ayjay** » Tue Oct 28, 2003 8:55 pm

ya for sure... and i wanna know how much power smug510 is putting out... DUDE let us know how it pulls compared to your turboed ka!! i'd be happy with 180HP N/A...

Post by **deviousKA** » Tue Oct 28, 2003 8:55 pm

Considering the current availability of ka oversize valves (slim), not much thought has gone into clearance with these and the ka24e piston swap.

Only the very early ka24e pistons (or nissan motorsports 9.1:1 pistons, same thing) would need a flycut relief for adequate valve clearance. Chances are most people will not be using these, and if so they would be a used set anyways. The price of these new from nissan motorsports is outrageous, and i have searched high and low for an affordable aftermarket version to no avail.

Post by **ayjay** » Tue Oct 28, 2003 8:55 pm

so deviousKA... you think with a set of street cams in the de head matched up with a 90' ka24e bottom end would work? like would valves be touchin the pistons? how would you be able to figure this out?

Post by **cory2081** » Tue Oct 28, 2003 8:55 pm

well, in tech school, we used a layer of play-dough on the piston (about 1/4") and assembled the head to it. Rotate the engine giving the intake and exhaust valves a chance to open fully. disassemble the head from the engine and you will see an impression of the valve in the play dough. by this, you can decide if the pistons need fly cut or not.

Post by **smug510** » Tue Oct 28, 2003 8:55 pm

wow i had no idea this thread would get so big , i am pretty happy with the swap , really in the begining i just wanted to do it b/c nobody has , i would say it pulls more consistantlly than the turbo , i have lots of tourqe low end and then it wants to still go but the cams limit it , but all in all if you like to fabricate and you want to do something different than this is a cool swap but if your not the most mechaniclly inclined than the piston swap would probably be best , i can definitly say that i am the first to do this , but i am giving up on it , the high comp datsun 510 is up for sale , i am going to pick up a 97 240 se and do a swap , i am definitly going with a rb26dett , the datsuns fast but not nearly fast enough , so have fun with the head idea

troy a.k.a. smug

Post by **cory2081** » Tue Oct 28, 2003 8:55 pm

Thats cool man. I know what you mean about not being fast enough. I went from a 450+rwhp Buick GN to a 96 240SX SE. I just had to have something sportier.....plus, after 11 years, I needed a new project. Right now, I plan to do a budget N/A setup until I get the money to go forced induction.

Post by **deviousKA** » Tue Oct 28, 2003 8:55 pm

ouch smug, oh well at least your going to an engine with excellent internal design. good luck!

hey ayjay, use modeling clay like cory2081 said. be sure to have head fully assembled, head gasket, head torqued when you do it. and make sure you have a good timing chain, this can change clearance majorly.

Post by **ayjay** » Tue Oct 28, 2003 8:55 pm

shiiit lotta work just to see if the playdough is still intact... damn outside of this thread, that would have sounded like the most messed up thing... :pface

well i guess that's the only option though to check and make sure it has enough clearance... but what about if i went with a 91 de head? don't the 91's have slightly more aggressive cams than any of the other years?

Post by **cory2081** » Tue Oct 28, 2003 8:55 pm

Well, engine building done the right way takes time. When I build one, everything is measured and written down.....from the bore diameter to the oil clearances on the mains, that's what you call blue printing.

Yes, the 91s (or the S13s with DEs, I've read that all those had the 248/240 cams) had slightly more agressive cams (more duration) If in doubt.....use play-dough!!!

ok guys here it is proof

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