Z32 Pistons in CA18DET

[Phyrx]

I got a motor from JHOT recently, and it was sort of a dud. No biggie. So I have bought another CA18 as a replacement until I can fully build this one.

When I received the motor, it had a blown head gasket and a slight knock. So I have torn the motor down, and found a metal headgasket, and polished rods. The bearings were ruined. The motor has already been bored 1mm over. That would make it an 84mm bore, correct? Well the cylinder walls are kind of rough, because the piston rings were rusted to the cylinder walls when I first got the motor. It was hydrolocked? So how should I bore it? Will I be able to find a headgasket and pistons to fit?

I was wondering if a CA18DET can be bored out to 87mm so that I can use some VG30DETT pistons. Would the wrist pins and everything be alike? I heard the CA and VG had similar designs in the bottom end.

What would that make my displacement and what advantages/disadvantages would I experience?

Thanks guys!

One more question! Is it common to polish the stock rods in japan? Because my motor had them polished when I opened it up. This motor has obviously been ragged on in JP lol It ALSO has a weird turbo.. my nissan guru friend said it was a EUROPEAN CA18 turbocharger? It seems to be the same specs as an SR20 turbo but it doesnt have the flanged inlet.. weird. It says A/R .80 on the front. lol

[r34 gtr]

you should talk to jhot, they will be glad to help you out from what ive seen. im not sure that its safe to bore the ca18 block that much, itll make for very thin cylinder walls. that turbo is a t25g from a sr20.

[Phyrx]

Yeah I know JHOT would have helped and they did offer me to buy another metal headgasket. But I'm not so worried about it, really. I was going to build one up just didn't plan on having to do it so soon

The turbo isnt the same as an SR20, looks wise. It has a different compressor housing. It doesnt have the flange on the inlet like the SR20 has. Trust me, my buddy has an SR20 and they are different. But the same specs. It looks like a stock CA turbo but with SR20 specs. Weird huh? Maybe I should get pics. Did the EURO CA's have different turbos?

What is the most anyone has ever bored a CA?

Anymore input?? Thanks!!

[r34 gtr]

ive seen some nismo pistons that were 89mm in size, so its gotta be possible. i just wouldnt do it for reliability issues. what if you wreck something and need to bore it again? also, what pistons were in your motor? 1mm over is huge, and i dont think they make overbore rings near that big. good to see your a scant hour and a half from me too.

[float_6969]

I suppose you could go out to 84.5mm but that's really pushing it and you won't find anything off the shelf in that diameter. They'll have to make them custom for you. Expect to pay around $600 for the pistons, rings, wrist pins, etc.

[r34 gtr]

and have see-thru cylinder walls.

[Phyrx]

Well my buddy measured the bore and it was 3.30 inches.

3.30 inches = 83.82mmThe pistons that were in my motor had the NISSAN logo stamped on them. My buddy really knows his stuff, so I wouldn't expect him to be wrong.

So your saying it would be VERY unreliable to bore my walls to 87mm and throw some stock VG30DETT pistons in there? I can have some for rather cheap and my friend is currently doing over 500whp on his VG30DETT with stock internals and no problems.

How would I find out the displacement of a CA with 87mm bore? And if anything ever happens like you say, than CA blocks arent that hard to come by! And I do have an extra CA18DET that I am going to keep around, and stock. So I can just throw it back in if needed, anytime. Plus, I have a daily driver.

[r34 gtr]

arent the stock pistons 83.5mm? that would make your engine bored .30 over. you could bore it another 20 thou and run some 84mm slugs, putting your car at 1.853l. i really wouldnt reccomend you run vg30 pistons, its just too much to bore. you can get some CP slugs for under five hundred i believe, so i would say thats the best option. if you are building the engine you might as well. also, 500hp isnt that fantastic, seeing as its got 2 more cylinders. that gives you about 335 on four, so i doubt they are any stronger than stock.

[Phyrx]

I thought stock was 83mm?

[r34 gtr]

so it is. sorry, got bore/stroke mixed up. its late, rawr. damn, thats a huge overbore! thats like a 1.9l! have you measured the pistons? are you sure they are stock ca18 slugs?

[Phyrx]

I haven't measured the pistons, but they don't like anything spectacular. Still have the nissan emblem imprinted underneath.. but like I said, the rods were polished when I opened up the block.

Let me get a pic for you guys

[Phyrx]

I know these pictures suck but it's the best I can do as of this moment.. and no measuring tape near me..

[Phyrx]

On top of the piston it reads from top to bottom:

100

JH4

56E2

I2

On both sides it reads near the wrist pin:

56 0S

[Phyrx]

Anybody have a pic of a stock CA piston by any chance??

[float_6969]

Nissan makes pistons for rebuilds in 83.5mm and 84mm diameters. It sounds like somebody got the 84mm pistons from Nissan and bored out the block.

I would call up http://www.raceeng.com and ask them what diameter you need the cylinder wall to be to run their 84mm pistons. Thier 84mm pisons are a stocking item and run less than $500 and there's no wait. Also, since they use CP pistons, they tend to run a little more cold clearance and you might be able to just clean up your bores and drop these in.

[Phyrx]

Would it be smart to re-use the stock rods that have been polished?? Or would that throw off any kind of important balance??

What can factory CA rods handle?? I dont want to be going into this motor again, and I am doing it right the first time. But why spend a grand on rods when you don't need 'em, right?

[float_6969]

The stock rods should be fine. I think they're good to 500 HP.

[Phyrx]

Sounds like a plan

[NUT-CSE]

There's no way you can bore the block to 87mm let alone 89mm. You will have paper thin cylinder walls.

Your rods have been race preped by thr sound of it which means they are good for 350hp.

Try finding pistons from other engines which use a 84.5mm bore. Like Honda B16, B20, Toyota 7MGTE etc Maybe even 85mm from a Mitsubishi 4G63, if you wanna bore it that far.

[float_6969]

Be careful when purchasing pistons for other motors as you need to check the pin height to insure that the piston will work properly.

[Phyrx]

So would I be better off buying a new block? lol... seems to tough to find the right piston... I kind of wanted to raise the displacement to 2.0 but I guess its impossible by just boring it out, huh?

[r34 gtr]

not true! its totally possible. tomei sells (sold) a 2.0l stroker kit. i think 84.5mm pistons would also put you at 1.95ish.

[NUT-CSE]

Yea the cheapest option is to buy another block and just bore it out to suit the oversized pistons you already have.

I dont think you can bore out a CA block to 2.0, you will need a 87mm bore and i dont think there is enough cylinder wall available to take it out that far. Just my opinion but id like to be proved wrong.........

[r34 gtr]

you could always use a ca20 block...

[Phyrx]

Ive read that using a CA20 block gets pretty complex

[mr2erdave]

Hi will you be reusing the pistons I was in the market for ca18det pistons for my toyota engine but if they are 83.5mm or less thanks David