chevy pistons?

[jkeyzer]

What is involved in putting chevy pistons in a 2.0?

I don't want to actually do it, but I do want to know what modifications have to be made to the case, heads, etc. How hard would it be to take one of these and rebuild it to a 2056 or 2270 (with German pistons)?

[jamcleod]

the pistons are the easy part! it's just the V8 block and associated radiator plumbing that is the chore!

[M. Hendrix]

lol

heh

[jkeyzer]

Very funny.

Somewhere on this or the other BBS I read something about Chevy pistons being used to make a big bore. Maybe it was with a bunch of type I parts? I forget. It looks like I am getting a 2.0L that had Chevy pistons put in as a core and I want to know what to expect when I open it up! Fingers crossed that the case and heads are still usable...

[DDS]

2056 short block just needs 96mm bore pistons and cylinders, easy. Mine case required a very minor amount of clearancing for the piston skirts.
2270 requires a stroker crank plus a bore increase, which means different rods (longer T4 rods don't seem to be realistically available) which means different pistons with usually T1 or chevy wrist pin diameters and journal sizes and may need some case or rod bolt clearancing. The longer stroke also means longer pushrods and resetting the rocker arm geometry, which can be really time consuming, plus a good look at bigger induction.
I blabbed on about all the variables in a thread awhile back, as I was considering the same options that you appear to be.
Good luck.
Dave

[M. Hendrix]

I don't know the variables, but yes, that is done.

I have no idea what the mods are, keep asking around, you aren't insane.


M

[DDS]

http://forums.pelicanparts.com/showthread.php?threadid=4005

Here's that thread

[Alfred1]

I don't know any of the details of putting Chevy pistons in a 914 but I have heard of it being done. My friend used to work for a Porsche repair shop many years ago and he mentioned that a 914 there had Chevy pistons. Pretty common to use Type-1 rods in a stroker motor, though.

[jkeyzer]

I don't really want the Chevy pistons in there because I have no idea if the work was done properly or what the builder's intentions were. It's just what the engine came with according to the PO.

I really just want a stock 2.0, although I would consider 2056 or 2270. 2270 might be more than I can handle but 2056 is probably not a big deal.

My concerns are that if the engine already has Chevy pistons in it, I may not be able to salvage the crank, rods, case, etc. as a core for my 2 liter or 2056. I am worried that they may have already been modified and might not be usable anymore in a less radical engine. Sounds like the whole valve train might be suspect too.

I asked my original question not because I want to build an engine with chevy pistons, but because I just got one and I want to un-build it into something more "normal". That is unless Chevy pistons are a good thing for a stock engine, which I doubt...

[DDS]

Is there something wrong with the engine other than the suspicious pistons? Does it run? What is the bore? You may actually have lighter or maybe longer than stock rods, which is kind of cool, and they may be useable for a stroker crank which is even cooler.
Are there big spacers under the cylinders or anything weird like that?
Was it a low bucks effort?
If you want to un-build it, you'd need a crank and rods for sure, and to check the pushrod length and verify if the heads were flycut as this changes valve geometry and CR too. Case shouldn't be more doubtful than normal.

Dave

[jkeyzer]

Doesn't the case normally need to be machined to accept the larger bore?

It is not known if the engine runs. No history either besides the part about the chevy pistons.

I won't know the bore or stroke etc. until I take it apart.

I haven't even seen the engine yet so I will know a lot more after the weekend.

[mike mueller]

is this the "free" motor??

Right now, the Chevy pistons mean NOTHING at all until you measure things to find out why they used them??? Could have been done cause that is what they had laying around and figured out a way to make them work.

All it'll take are a few measurements to figure out how "radical" the motor is...the only things I can think of to make a motor too much for street use is wild cam (which can be easily replaced) and wild head porting (sketchy ground here, depends on how much work was done such as porting or huge valves) and too high of a compression (this can be fixed with spacers under the cylinders or copper gaskets between the head and cylinders)

You are sweating this too much, unless everything is garbage inside of the motor from damage, you'll easily be able to trade for bone stock 2.0 parts if the motor is indeed "Trick"

If you get the motor within the next week and take it apart, I can meet you for lunch and I'll bring some of my stock 2.0 parts and we can do a comparison if you wish (crank, rods...)

[jkeyzer]

It is the one you think it is Mike. I couldn't pass up the opportunity.

I may not have it apart by next week. We'll see. I will hopefully be able to take you up on your offer soon though.

I am pretty optimistic about what I will find. Even if the heads are the only usable part I am still way ahead of the game for the money.

[DDS]

Mike - are chevy rod jounals or wrist pins the same dia as T4 stuff? I believe at least the journals are different, if not both.

[Acox914]

ah...your the one who got to the engines before me! i wanted the 2.0

[Dave at Pelican Parts]

The wrist-pins are, I believe, different sizes. So either someone has bushed the Chevy pistons to work with the 914 rods, or someone has bushed the 914 rods to work with the Chevy pistons, or more work was done and someone put in a crank with Chevy journals and used Chevy rods as well... Lots of ways that it can be done...

--DD

[Ron Meier]

The make of the pistons should make no difference other than the following characteristics:

1. Material - whether compounded for air cooled or water cooled meaning expansion rates of the material.

2. Cylinder Bore Size - related to #1 and a hole can be whatever you want as long as there is enough material in the walls to take the stress.

3. Piston Pin to Piston Deck Height - This factor could leave the piston down in the bore or push it out of the bore - a fact taken into account in rod length.

4. Piston skirt length - A factor in the stability of the piston in the bore.

5. Piston Deck Shape - Hey, they're dished, flat and pop ups (crowns). As long as they don't interfere with flow into the cylinder - who gives a rats a$$ - it's compression ratio.

6. Piston Pin size - see #2 - as long as there is enough material to hold the bushing - use any diameter you want.

All in all, It won't make a crap worth of difference if they are Kolbenschmidt, Mahle, Chevy, Dodge, Arias, Keith Black, JE and whoever else punches them out.

There is more, but that's what books are for - READ EM or hit the library and learn!

Oh BTW - 94mm is 3.70" If I were to choose a Chevy piston close to this, it would be the 305 which is a 3.740" bore or a 262 which would be a loose fit at 3.671".

[Jake Raby]

Hey.....I'm using a Chevy Bore size in my neswest combo

The bore size is 4.137 thats a 400 Small Block bored .010 oversize.

The engine is a 2774cc MassIVe powerplant...

The 96mm pistons I use are made for a Ford Pinto engine!!!! If you have correct clearances, you can use any piston you want!

[bpick84]

You need to check-- some CHevy pistons have an offset wrist pin.

[skline]

The wealth of knowledge here just never ceases to amaze me.