Pistons, boring, etc

[Hybird]

Well time is coming pretty soon here that I will have the funds for a nice set of forged pistons. I was looking mainly at the WiseCo ones from J-body Performance. Would anyone recomend these? I cant find any other forged ones. I plan on going pretty high boost (turbo).

Also I was wondering what your opinions is on boring out my 3.1 to a 3.2? Should I do it.. or will the wall thickness be too thin? As it sits, stock bore is nearly mint condition, could get away with a honing and drop the pistons in. I'm pretty sure that I will go 0.020 over just to get a true bore again. Oh this is a 3.1 fergot to mention

So will it be worth it power gain wise to bore to a 3.2 or should I just keep the security of a thicker cylinder wall?

[sharkey]

RE: Pistons, boring, etc

people have bored 3.1l blocks .120 over to make a 3.4l. this is not ideal. it leaves cylender walls paper thin, but i havnet heard of any massive problems from it.

you are talking going to 3.2l. if i remember right, thats .040" (1mm), and thats well in a safe range. anything up to .060 is industry standard. as your bore may be near mint condition, most aftermarket pistons have way less piston to wall clearance that stock (.002-.005" for aftermarket) and you would have to bore the block and put in oversized pistons anyways to get the piston-wall right. performance gains going to a 3.2l, hardly any. better going with the smallest oversize you can get away with.

now those pistons are NA high compression pistons and not ideal for boost. for a boosted aplication, you may want to go with a custom piston. you are going to want to be around 8:1 compression for high boost. one option may be those pistons with ported cast iron heads.

[oil pan 4]

RE: Pistons, boring, etc

I wish more people knew this.
When ever I'm on thirdgen.org I get flamed for saying you can bore any 60-V6 more then .040'' over. Even when the cylinder bores are a min of 4.5mm thick from the factory.
You don't want to bore it much for a power adder engine.

[Doubt_Incarnate]

for n/a boring is one of your only options to increase cid. consequently your slightly greater displacement ups the cr a little. for boosted motors, your forcing air in to increase the displacement. a little stupid math is Displacement x PR = new displacement, i.e; 3.1 x 1.54 (8psi) = 4.8L. 54% more air/displacement. alot more than anyone can get by boring.

i think Ross pistons can do a base set of pistons to your specs for $500. i think, its been a while scince i last checked into it.

[Hybird]

I never really looked at the site for Ross Pistons, they dont seem to have any made for the 192ci engine. So I guess I would have to get them custom made. These are a forged aluminum corrrect?

How about those coatings you can get on the pistons? I was thinking maybe the theral cermaic for the tops. As for boring, I suppose I will just bore out to smallest size over if I'm not going to get a great deal of gain from going to a 3.2. Might as well stay on the safe side.

now those pistons are NA high compression pistons and not ideal for boost. for a boosted aplication, you may want to go with a custom piston. you are going to want to be around 8:1 compression for high boost. one option may be those pistons with ported cast iron heads.

Well It says on the site that you can call in and ask for different compression, so they are mainly custom pistons as well, which is why I thought that way might be a good idea. But after looking at Ross Pistons, I kinda think I will be heading that direction.

As for the heads I will be using 3400 cylinder heads, and so cast iron is outta the question.

[sharkey]

ok for 3400 heads and boost, you will need a custom piston. i beleive those wiseco pistons will get you around 9.7:1 compression. you would be able to get away with 5lb boost, but not high boost.

[StudlyCamaro]

you can boost a motor that has 9.7:1 compression as long as its intercooled properly

[TurboZ24]

I got my pistons from Ross, yeah. They will custom make pistson for about anything, and since I needed them with the SBC wrist pins, wasn't a big deal. They are forged, actually I think the Ross ones are Billet Forged, at least mine were. I think I paid around 450ish for all 6.

[Hybird]

Hey curtis, when you got your pistons from ross did you make use of any coatings on the skirt/top?

[Hybird]

Anyone know about these coatings? are they just a way to scam more cash outta ya, or do you think they would benefit the motor?

[bszopi]

There are many good coatings out there. I can think of the stuff from Airborne that I have read good stuff about. I'm sure what Ross offers is similar, if not actually from Airborne.