4.3 vs 3.8

[all4gss]

Howdy gang,

My ultimate goal is to put together a sy-clone and matching TR. I would like them to have the same drivetrain. So i'm debating on which is better. The 4.3 or the 3.8. I've read a few places exclaiming that the 4.3 is essentially the stock vortec motor with dished pistons yielding a lower CR for the turbo. So basically... Which has the most potential? What are the pros/cons of each... and what would you do?

so lay it on me... 4.3 vs 3.8, which makes the best turbo engine?

TIA

Keith Grant

 

[tjthorson]

There is no contest here. Even the 4.3 sy/ty guys know this answer.

The Buick 3.8 is a much more stout and sturdy block, and will handle much higher boost levels then the 4.3.

 

[INEEDAGN]

The 4.3 bottom end doesn't seem to be as well engineered for a turbo application (especially the rods) but some of the internal engine components are cheaper because they interchange with the sbc. I am pretty sure the 4.3 bottom end is stock except pistons. I don't know about the cam and heads. My buddy is rebuilding a wrecked sy and it's gonna be VERY nice but he's easily going to have twice what I have in my nice GN. If I remember right it's gonna be over 20k. I've kinda looked into this before I decided which one to buy and it seems you're gonna spend more money making the sy go fast because of the extra weight and extra parts cost due to lower production numbers.
This is purely just my opinion but I think the 3.8 is a better engineered motor since they had a few more years to make everything right. Either way they can both be made to go fast but the sy parts are more expensive and less people make parts for them.

bob

 

[all4gss]

Well i kinda figured that. I read that the maximum boost recommended for the syty was around 19psi or so. I've heard of plenty of people going north of 25psi in the GN/TR crowd.

So, my next question. Aside from weight and worse gears. Anything wrong with putting a 700-R4 behind a 3.8?


Thanks a bunch,

Keith

 

[myclone]

Originally posted by all4gss
Well i kinda figured that. I read that the maximum boost recommended for the syty was around 19psi or so. I've heard of plenty of people going north of 25psi in the GN/TR crowd.

So, my next question. Aside from weight and worse gears. Anything wrong with putting a 700-R4 behind a 3.8?


Thanks a bunch,

Keith

See my reply to this same post in the syty topic about the engines. FWIW as stock bottom end will tollerate 26psi for a while IF you dont detonate it. Let it detonate and you'll drive over the crank in no time.

Dont bother with the 700 if you are doing a LC2 swap into an s10 unless youre going all wheel drive. It takes lotsa $$$ and the know how to build a 700 that will live with AWD and anywhere below 11.50s or so. Stick with the 200 if you can.

 

[typhoon]

I have both.

3.8L blows headgaskets
4.3L blows cranks/rods

Take your pick.

Both have good things. I would say stock for stock the buick is the better choice.

4.3 to go fast requires work inside as mentioned. Stock rods are the stregth of toothpicks.

Cranks are becoming hard to find.

If you building a clone, go buick for sure.