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

[InsanityInc]

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.

I've seen one dyno of JWT cams, and it wasn't very impressive. Even less results than the unimpressive ones from the PDM cams. People focus too much on massive overlap when they're making cams. Intake closing is FAR more important.

[Bigvinnie]

I've seen one dyno of JWT cams, and it wasn't very impressive. Even less results than the unimpressive ones from the PDM cams. People focus too much on massive overlap when they're making cams. Intake closing is FAR more important.

What bugs me the most is that these are all N/A cams. KADET has become popular over the last few years, yet there are still no companies besides colt cams (a division of PDM), and crower cams that have tried to design better F/I cams for the KA. It sucks that companies like HKS usa, and greddy havn't developed anything for the KA F/I platform, which are the 2 major contributing companies to the import performance car platform. Maybe the fact that the KA is a USDM might tarnish there image, (who knows what it could be).Greddy I would assume would try to develope some cams just because they make a KADET kit. Now how do they expect to sell a system without moderate cam upgrades?It just isn't fair to give the SR guy's an advantage in the market place while the KA guy's have to sit and wait for developement, if there ever be any.But then again I have seen alot of people improvise and take a shot in the dark using the CADET cam specs. Lets hope that the market place for KADET isn't bleek, it is defenitely a breed of engine that deserves its fair turn on the F/I platform.

[uncle_louie83]

vinnie...ive been building engines for years....and ive done the math over and over. with a 96mm stroke on the ka engine you cannot see more than 7980 rpms mathmatically. BUT and when i say but i meen BUT...your forgetting one big thing. WE DO NOT HAVE enough oil pressure to sustain 8000 rpms safely. Our oil pumps push out enough oil for 7300 rpms safely for all day use. BUT we can take our engines up higher BUT we will end up spinning rod bearings later down the road. You need proper bearings plus you need the oil pressure for high rpms. PLEASE people before you go revving your ka to 8k rpms please think about your oil pressure loss. I use 10w40 in my ka and i get around 70 to 75psi at 7k rpms. We need more than that to go higher. If you use 5w30 your pressure will be 10psi less. Normal pressure is around 55psi on a decent used engine. I have a fully built engine with the best fluids i can give it and thats why i get the oil pressure i need. but go ahead...blow up your ka and dont listen to me

[Bigvinnie]

vinnie...ive been building engines for years....and ive done the math over and over. with a 96mm stroke on the ka engine you cannot see more than 7980 rpms mathmatically. BUT and when i say but i meen BUT...your forgetting one big thing. WE DO NOT HAVE enough oil pressure to sustain 8000 rpms safely. Our oil pumps push out enough oil for 7300 rpms safely for all day use. BUT we can take our engines up higher BUT we will end up spinning rod bearings later down the road. You need proper bearings plus you need the oil pressure for high rpms. PLEASE people before you go revving your ka to 8k rpms please think about your oil pressure loss.

I've looked into the oil cooling, and oil pressure myself. An rb25det oil cooler will add 2 more quarts of oil, as far as the pump is concerned you can convert directly over to the L28turbo pump, it's a direct fit, devious KA sells this item at http://hybridka.com/sohcoem.htmYou also need to convert to metal gaskets.I would run on synthetic, I wouldn't waste my time with petro oil, especially for high rev.
Modified by Bigvinnie at 9:39 PM 8/29/2005

[InsanityInc]

vinnie...ive been building engines for years....and ive done the math over and over. with a 96mm stroke on the ka engine you cannot see more than 7980 rpms mathmatically. BUT and when i say but i meen BUT...your forgetting one big thing. WE DO NOT HAVE enough oil pressure to sustain 8000 rpms safely. Our oil pumps push out enough oil for 7300 rpms safely for all day use. BUT we can take our engines up higher BUT we will end up spinning rod bearings later down the road. You need proper bearings plus you need the oil pressure for high rpms. PLEASE people before you go revving your ka to 8k rpms please think about your oil pressure loss. I use 10w40 in my ka and i get around 70 to 75psi at 7k rpms. We need more than that to go higher. If you use 5w30 your pressure will be 10psi less. Normal pressure is around 55psi on a decent used engine. I have a fully built engine with the best fluids i can give it and thats why i get the oil pressure i need. but go ahead...blow up your ka and dont listen to me

Uh, well, the nissan race frontier truck revs to at least 8600rpm, since that's where it makes peak power, and it has a KA in it.

Quote »What bugs me the most is that these are all N/A cams. KADET has become popular over the last few years, yet there are still no companies besides colt cams (a division of PDM), and crower cams that have tried to design better F/I cams for the KA. It sucks that companies like HKS usa, and greddy havn't developed anything for the KA F/I platform, which are the 2 major contributing companies to the import performance car platform. Maybe the fact that the KA is a USDM might tarnish there image, (who knows what it could be).Greddy I would assume would try to develope some cams just because they make a KADET kit. Now how do they expect to sell a system without moderate cam upgrades?It just isn't fair to give the SR guy's an advantage in the market place while the KA guy's have to sit and wait for developement, if there ever be any.[/quote]There really isn't a lot of difference between turbo cams and NA cams. Basically, NA cams have more overlap, because they require a bit of it to get maximum cylinder fill. Turbo cams generally have slim to no overlap, because due to the boost pressure, you're probably just going to lose cylinder fill. Also, turbo cams have a later intake closing, due to the turbo trying to shove air into the cylinder, and they generally have an earlier exhaust opening as well, since you want a high pressured exhaust stream to spool the turbo well. Lucky thing is, you can adjust all those things with a DOHC setup. That particular set of effects would be achieved by retarding the intake cam and advancing the exhaust cam.

[Bigvinnie]

There really isn't a lot of difference between turbo cams and NA cams. Basically, NA cams have more overlap, because they require a bit of it to get maximum cylinder fill. Turbo cams generally have slim to no overlap, because due to the boost pressure, you're probably just going to lose cylinder fill. Also, turbo cams have a later intake closing, due to the turbo trying to shove air into the cylinder, and they generally have an earlier exhaust opening as well, since you want a high pressured exhaust stream to spool the turbo well. Lucky thing is, you can adjust all those things with a DOHC setup. That particular set of effects would be achieved by retarding the intake cam and advancing the exhaust cam.

So to sum it all up to prevent over lap durations are made shorter, while the lift is made slightly higher. Preventing the two cams further away from overlaping. Kinda like in N/A where as the 248/248 the exhaust to the 248 has to be retarded in order to make power, where as the intake has to be advanced...Right?I hope I'm making sence cause I'm starting to confuse myself a bit...

[InsanityInc]

So to sum it all up to prevent over lap durations are made shorter, while the lift is made slightly higher. Preventing the two cams further away from overlaping. Kinda like in N/A where as the 248/248 the exhaust to the 248 has to be retarded in order to make power, where as the intake has to be advanced...Right?I hope I'm making sence cause I'm starting to confuse myself a bit...

Well, the LCA is altered to change the overlap, not necessarily the cam specs. Also, S13 cams are 240/248. Advancing the intake cam and retarding the exhaust cam would increase the overlap, by reducing the LCA, but would also create an earlier intake closing point (bad). While some overlap is good, a proper intake closing is MUCH more important for high-end power, and is less detrimental to emissions and low-end power.
Modified by InsanityInc at 6:08 PM 8/30/2005

[scruffy63]

Hey Jesus where do you stay in spring valley. I grew up there I stayed on albacon. off of forest brook.

[S13Coupe]

Anyone actually tried using these oil pumps? Don't know if they're worth it, but if it's good quality, it could be a good investment in your engine.http://www.importperformancepa....html

[Bigvinnie]

A 2 year warranty for upto 800HP sounds like a pretty good deal.

[Deadrodent]

hmmm...isn't the stroke of the KA the downfall in regards to high rpm revving? Even with forged internals isn't it putting unnecessary strain on the internal components since the pistons are moving up and down at an incredible rate?

[Bigvinnie]

hmmm...isn't the stroke of the KA the downfall in regards to high rpm revving? Even with forged internals isn't it putting unnecessary strain on the internal components since the pistons are moving up and down at an incredible rate?

Hey best

Uh, well, the nissan race frontier truck revs to at least 8600rpm, since that's where it makes peak power, and it has a KA in it.

What stress are you talking about exactly? All engines go through all forms of stress. The purpose of using forged rods and pistons is to prevent a bent rod. The stress is always there, but there are othere methods of freeing up stress. The KA has a massive crank also, the crank can be knife edged in order to break the resistance at higher RPM, reducing vibrational distortion. Having a much more free flowing crank will also reduce stress from rods and pistons, and allow the valves to open and close much more fluidly, well as long as you also use titanium retainers and springs.

[InsanityInc]

Hey best

What stress are you talking about exactly? All engines go through all forms of stress. The purpose of using forged rods and pistons is to prevent a bent rod. The stress is always there, but there are othere methods of freeing up stress. The KA has a massive crank also, the crank can be knife edged in order to break the resistance at higher RPM, reducing vibrational distortion. Having a much more free flowing crank will also reduce stress from rods and pistons, and allow the valves to open and close much more fluidly, well as long as you also use titanium retainers and springs.

The stress on everything is higher with a longer stroke because the average piston speed has to be higher at any given RPM, since an RPM level is a measure of revolutions per a time unit, but each revolution in a longer stroke engine is a longer distance.

But the thing is, there are many large-displacement american V8 strokers running with much better high end performance than a KA.
Modified by InsanityInc at 7:08 PM 9/8/2005

[nissanparts.org]

if someone wants to try this out...

dohc head on sohc block + high comp forged 90 size sohc pistons = 13:1 CR?

that then going complete rebuild on the head with stage 3 items and forged rods and balancing everything and knifing the crank and a oil cooler and other na items will give out some very impressive number.

I am GUESSING 225whp?

[InsanityInc]

if someone wants to try this out...

dohc head on sohc block + high comp forged 90 size sohc pistons = 13:1 CR?

that then going complete rebuild on the head with stage 3 items and forged rods and balancing everything and knifing the crank and a oil cooler and other na items will give out some very impressive number.

I am GUESSING 225whp?

You don't need an SOHC block. If you put the 89 pistons in a DE, you get an 11.1:1 CR. The head also doesn't need beefing up unless you want to run really high lift cams. People have already gotten above 200whp with KAs, it's very doable and cheaper than an SR swap.

[Deadrodent]

You don't need an SOHC block. If you put the 89 pistons in a DE, you get an 11.1:1 CR. The head also doesn't need beefing up unless you want to run really high lift cams. People have already gotten above 200whp with KAs, it's very doable and cheaper than an SR swap.

where can i find info on these engines? it would be cool to try building an NA engine and a turbo engine considering i just bought another shell with a kade engine and transmission...

[InsanityInc]

where can i find info on these engines? it would be cool to try building an NA engine and a turbo engine considering i just bought another shell with a kade engine and transmission...

There isn't really a whole lot out there unfortunately. It's growing, though. Your best place would probably be old datsun forums. They use KA24 engines for swaps a LOT.