To those w/ experience: How/What to rebuild KA?

[jtsarnak]

To start off, I would like to rebuild my KA24DE from my '95 SE. The engine has just a tick over 120k on it and I am planning on adding the GReddy turbo kit at a later date. So my goals are pretty simple: Keep the stock compression ratio, possibly do some headwork for flow, clean out and ready the engine for a future turbo (which I will be running at stock boost, no crazy numbers). In short, I want the engine to be as close to new without actually replacing it (unless someone knows how much a replacement 0 mileage engine is). So the question I have is, what do I need/should I get to rebuild it, as my brother (who is well versed in chevy big blocks, but wants to try his hand at this) is going to help me pull and rebuild it, sourcing out any necessary stuff to local shops. I am ignorant as far as this goes, and my brother won't help me unless I come up with the answers. Any suggestions and advice would be helpful, any negative comments about my plans will not be.

[Turb0wned]

search they have other fourms just like this one

[Checkered-Member]

well this is what you can do...buy a newer ka24de...they go for cheap, really cheap 200 at most 500 for one with very low miles and in good condition but again prices very so much. You might have that, open it up, blue print it to make sure its perfect, clean it up replace all gaskets and seals, do some head work, port intake manifold, add some cams.

All this *should cost about 1500-2000 without the engine, depends on what can you do yourself and if you are getting a good deal

And swap it with the old engine…boom you’re done.

[fiznat]

if you're gonna rebuild it, and you want to turbo it, why would you want to keep the stock compression ratio? I'd say get some nice 8.5:1 compression pistons, use the stock rods, and replace all bearings, gaskets, and seals. With the bore and the seals, your engine should be pretty damn close to that "new" feel you wanted-- and you'd also be ready for turbo with those pistons.

Pistons = ~$500Machine Shop (bore, balance, clean, assemble short block) = $500Misc Parts (bearings, gaskets, etc) = $150

Not too bad of a price I'd say

[jtsarnak]

The reason for keeping the stock compression is that I plan on turboing in a basic fashion, not high boost, so the stock compression will do @7 psi or so. I just need to know if these rebuild kits are all I need or if I should look into other options. (and which rebuild kit is the best)

[MarkEmark]

Yeah right...

That's what I told myself--"just 7 psi"....You'll want more, very, very quickly. Boost is incredibly addictive.

If you're gonna rebuild it/pull the block, do the whole thing. Lower the CR, add some forged pistons, new rods, etc--I figure if you're gonna go through all that trouble to pull the block, why not rebuild it to last forever? However, I've heard that the pistons are the weak-link on the KA. So I guess you could get away with just getting some forged lower CR pistons/rings--then do whatever else you wanted to do and you should be alright for a good amount of boost.

Marc

[C-Kwik]

Yeah right...

That's what I told myself--"just 7 psi"....You'll want more, very, very quickly. Boost is incredibly addictive.

If you're gonna rebuild it/pull the block, do the whole thing. Lower the CR, add some forged pistons, new rods, etc--I figure if you're gonna go through all that trouble to pull the block, why not rebuild it to last forever? However, I've heard that the pistons are the weak-link on the KA. So I guess you could get away with just getting some forged lower CR pistons/rings--then do whatever else you wanted to do and you should be alright for a good amount of boost.

Marc

While boost is very addicting, the solution may be simpler. POersonally, I'd check the existing motor out and see if it might be able to handle some mild to moderate boosting. The parts in the motor are fairly durable, so all you need to do is make sure that wear isn't an issue. Particularly compression and leakdown. If these two are fine, and you aren't getting strange noises, then your KA can probably handle some boost. Install the turbo kit, then decide if you want more boost.

The reason I'd try to do it this way is that even if I rebuilt my block, if I decided I didn't need more boost than what the kit is set for, then I would keep the CR the same even if I used forged internals. In fact, if I were to continue my KA project, I'd probably run some 15 psi on 9.5:1 CR pistons. I prefer not to lose any off-boost response or drivability so long as the motor can handle the power level I want. I doubt I'd want any more than 350 HP on my KA since it's used for track events. It'd be so much of a headache already at 350 HP with the cooling system. And 350 RWHP on a 240sx is plenty of power. Of course if I were to be building a drag race KA, I'd be thinking very differently.