350 pistons in a 3.8 question.

[GrampaMike]

If you use 350 pistons in a 3.8 would the Compression ratio be higher as the CR rating for the 350 pistons is based on 59 cc heads while the 3.8 heads come in at 48 cc's? If my math serves me correctly, that would mean a 350 8.5 piston would produce appx. 10-1 CR with the smaller heads.
What other, if any, mods are necessary to get the 350 pistons to work in the 3.8?
TIA

 

[kary]

It is more complicated than just changing pistions to change CR.

The pin placement in the piston is based on the stroke of the engine. For instance a Chevy 350 (4 inch bore) has a different piston than a Chevy 302 (4 inch bore). Different pin placement for different stroke. This will affect where the piston is placed when at TDC to reflect the different stroke. Both motors use the same length rod.

 

[REDS HOT AIR]

non turbo 3.8 piston is same piston as 350 non turbo piston

in my speed pro book they both carry the same part #

 

[kary]

I am so use to thinking Chevy when I see 350, that I did not consider a Buick 350. Big mistake on a Buick board.

I see that Buick made a 350 with a 3.800 bore, the same bore as the Buick 3.8.

The engines do have different strokes, so for my own reference, do they have different rod lengths, or could the distance from the crank centerline to the deck height differ?

Didn't Buick also make a 350 with a 4.057 bore?

Being able to use the 350 pistons should open more possibilities for modifications to the 3.8.

 

[b4black]

While the 231 V6 is a Buick 350 less two cylinders, 75% of 350 is 262, so not everything is the same.

 

[GrampaMike]

Originally posted by b4black
While the 231 V6 is a Buick 350 less two cylinders, 75% of 350 is 262, so not everything is the same.

True. Still, The pistons from the 3.0 and the 350 are said to work in the 3.8. What I want to learn is what effect will using them have when used in the 3.8 configuration? The 3.0 flathead piston is said to produce a CR of 14-1 when used in a 3.8 block. What i need to find out is what other change and mods must be made when these other pistons are used.
That's why I was shamelessly trolling for Ruggle V6 Book all over the site. (I'm sorry for the cross posting Faux Pas, no harm intended.)
My goal is to build a 240 HP NA motor on the cheap. I figured by using these pistons I could get the results and still use OEM parts. They don't say I "throw nickles around like they're manhole cover", for nothing.