3.0l stroker V6, HELP!

[scberetta3800]

I'm in the process of purchasing all of the parts or having them made for a 3.0 stroker V6. I have a 2.8 V6 and a 3.4 V6 that i'm making the engine out of, but I was told that i needed to get special pistons. no one told me if i needed to get longer connecting rods. if the blocks have the same dimensions then all i would need would be to take the 2.8 crank and rods and put the 3.4 pistons on them and put it all in the 3.4 block right? please correct me if i'm wrong. if anyone has done this before it would be great if they could give me any insight on this. and if anyone has run across this on the web let me know!

[SappySE107]

The 2.8 and 3.4 have the same rods so you need custom pistons for that shorter stroke. You aren't making a stroker 2.8, you are destroking a 3.4.

[scberetta3800]

who sells custom pistons and how much am i looking at for pistons? what would i need for a 2.8 stroker, since i'll just have a 2.8 lying around i might as well make the most of it.

[SappySE107]

Well, a 2.8 stroked is called a 3.1 so just get a 3.1 crank, rods, and pistons. Wiseco can make custom pistons, as can JE, Ross, and many other places. You have to provide the specs.

[IsaacHayes]

yeah which are you wanting to do? Make a big bore/short stroke 3.1 with the 3400 block and 2.8 crank?

Or upgrade a 2.8 block to 3.1l (which you get a 3.1 crank/rods/pistons).

The changes went like this from GM:
2.8mpfi
3.1mpfi (stroked out)
3100sfi
3400sfi (bored out)
3500sfi (bored out)

Keep in mind if your beretta is older than 93 I think it is, that you'll need a custom mount like the j-bodies do for the 3400 block to bolt up.. not 100% sure on this, but I'd look into it.

[scberetta3800]

Big bore short stroke 3400 and 2.8 crank, ya know, the one that'll scream!
i'm not sure if i'm going to put this into the '88, cause i'm looking at a 95 beretta that i know will drop right in, if only i could put that getrag in without too much trouble!

[bszopi]

Do a search for destroked and see what comes up... This has been talked about numerous times in the last 3 years.

http://60degreev6.com/showthread.php?t=35429&highlight=destroked

[fivepointhustla]

Ditch the 2.8 block they suck.

[scberetta3800]

I could give a piston company some 2.8 specs with just a 3.4l bore size right? the wrist pin location is the problem no? so 2.8 pistons (if we forget the wrong bore size) will have the correct deck clearance that i need, so just modify the specs?

[scberetta3800]

2.8s may suck, but i'm getting great gas milage out of mine. in my 5 speed 2.8 88 beretta the highest average highway MPG over one tank of gas was 38! it helps alot going 120 miles a day for school! can't hate it too much.

[fivepointhustla]

Sounds like sweet build Good luck.

[Will'sFiero]

GM produced these configurations:

2.8: 89 x 76
3.1: 89 x 84
3.4: 92 x 84
3.5: 94 x 84
3.5: 99 x 76
3.9: 99 x 84

Putting a 2.8 DIS crank into a 3400 block will give you a 3.0. Putting the same crank into a 3500 (94mm) block will give you a 3.1.

If you're getting custom pistons made (~$100 each w/ pins), then buy a set of 6 inch small journal Chevy V8 rods and have the pistons cut for those. The stock rods are 5.700, so you'll gain .300 of rod length as well as going to a short stroke... recipe for a MEAN engine.

The 60 degree deck height is 8.818 IIRC. Going from a 3.307 stroke to a 2.992 stroke will lower the pin by 0.157. Going to 6.000 rods will raise it by .300, so you'll end up with ~0.143 less compression height than a stock 31/34/3500.

[RacerX11]

GM produced these configurations:

2.8: 89 x 76
3.1: 89 x 84
3.4: 92 x 84
3.5: 94 x 84
3.5: 99 x 76
3.9: 99 x 84

You forgot the 2.5L Chinese market engine.

[scberetta3800]

Well, i'd like to stick with the original rods because of availiblilty and price. but was i correct in my post about the new piston's dimensions? I think what i need is a 2.8 piston with a 3.609" diameter right? that way the piston comes to the top of the block and will give the correct deck clearance but with a shorter stroke using the original Rods.

[Will'sFiero]

You forgot the 2.5L Chinese market engine.

No I didn't.
Can you get that crankshaft here?

Ok, for the record, Buick of China build a 2.5 litre Gen III engine that was 89 x 66.7. This is more or less the niftiest crank GM made for these engines, but it might as well be unobtainium because it's only used in Chinese market cars.