Piston and con. rod options for a KL-DE turbo

[nissanfreak8]

Ok, first off I am not a newb to the whole import scene. I am pretty much a guru when it comes to Nissan (j/k), but I do know my fair share about engines and boosting them. I do all my own engine work and suspension, but enough small talk.

So here is what is up. My buddy decided he wanted to remove his K8 with a blown H.G. and do either a ZE or DE swap, well somewhere in the mix he decided to turbocharge it, and he found a local DE out of a '93 626 that is good. Got that for like $375, sweet. Got it loaded in my truck only to blow a heater hose 15 miles from home. Sucks. Got it home finally. Started tearing in to it. Never had a problem with it. Now we are to the point of starting to put everything back together. I have been on these forums as well as a few others reading faq's and searching for hours when I should be reading my book for the Navy. I digress.

Question #1
As I see it I have 3 options for piston/ con. rod setups.
1. Stock, shot peen the rods, clean the pistons, new rings, hope they hold up to 10 psi.
2. Import performance parts $1800 8.5cr pistons, con. rod, and ring set.
3. Wiseco pistons and Millenia S rods.
I am leaning toward the third choice, and from what I have read it should hold up to what he wants.
What would be your guys recomendations?

Question #2
I have a t25 turbo sitting around my house, but from what I have read the t3/t4 is a better fit for the 2.5L.
What is gonna be more suited for daily driving but also winding the car out once in a while?

Question #3
Will a stock mls H.G. be okay or should I look for an aftermarket one? Links, maybe, please?


I am sure I will be adding questions as I go.
Flamers flame away, people with real knowledge, please chime in, I wanna learn all I can, because I am looking at a MX3 for my next car after I get my KA built and screaming.
I will greatly appreatiate any help from y'all and Thank You in advance.

P.S. What about head bolts, stock or aftermarket?

[se7en]

MLS head gaskets are pretty good as far as holding boost...

cometic HG's are that style, but way better quality....I think stock MLS HG's would be fine for 10 psi though...

[onlytrueromeo]

Stock should hold up to 10psi with a good tune no problem. I would say no to 8.5CR pistons...I don't like the idea of having no power without boost and having a harder to start car. I would get at least 9 or 9.5CR pistons if you're getting ones made, heck a 10:1 would be similar to having a turbo ZE but w/ custom pistons itd be nicely stronger! Millenia S rods should work fine - if you're set on getting your own rods, then definitely get higher CR pistons than 8.5:1. You will have more power down low, and will make more power overall w/ same boost level (not to mention reduced lag time)

[93SOHC]

+1^

10:1 compression w/millenia S rods. That is basically the exact set up I will be shooting for with my turbo DE build next summer

[se7en]

geez guys, I would run 8.5:1 and intercool it with 20psi....way more power on pump gas than 10:1 and 5-7psi...

[onlytrueromeo]

If you have higher compression pistons you don't have to push as much boost which means less lag time and less loss through an intercooler. Yes you COULD just keep turning up the boost and it would be way more power than 5-7psi on a higher compression motor, or you could get 10:1 and 10-15psi and be right in the same range, not to mention having a better powerband. Why wait for 20psi when you can get the same power w/ less boost?

[se7en]

10:1 and 10-15psi would = detonation with pump gas.

5-7psi is the most you could run with 10:1 compression.(and that is with an intercooler)

[onlytrueromeo]

That is not true. There are people w/ ZE's that are running 10psi on pump gas.

[se7en]

okay, with a perfect tune maybe....but most people don;t have a perfect tune....also, a lot of boost can be run as long as you retard the timing enough...but then you are losing power anyway....the proper way is 8.5:1 with lots of timing(proper amount), and 20 psi boost.

garanteed more boost....we could argue this all day, but more boost is always more fun.

[se7en]

one other small thing...just because you pissed me off....

are you turbocharged?

[onlytrueromeo]

Heh...not turbo'd yet, but have been doing LOTS of reading over the last couple years for when I eventually take the plunge. Probetalk and mx6.com have done alot more turbo setups w/ the KL's than I've seen here. Most people are more than happy with the results of a turbo ZE - and thats on stock internals.

Yes 20psi will make more power overall, but I don't like the negative aspects of going to a lower compression motor. I hope to build a motor someday w/ 9.5:1 CR pistons, a nice meth/water injection system and intercooler running 10psi easy.

[tehbrookzorz]

Group hug!

[onlytrueromeo]

[Mnemonic]

does it matter if he is or not? Your information was wrong there are Lots of guys running over 7psi on Probetalk with NO problems on 93, 5-7psi on a ze is the Safe range, that is to say your tune can be a bit more relaxed than running 10psi. I agree in order to pull 10psi you need to do a better have a good tune, but i've seen a Ze running 16psi on 93 and yes it did eventually go but not till after 20k miles and daily driven.

[marcdh]

are you turbocharged?

are you ZEd? Just kidding, come and fix my megasquirt