Difference between turbo and non turbo blocks
- Thread starter bstatti
- Start date
kingots2004
Member
- Joined
- Nov 6, 2007
are the decks not thicker on a turbo car block?
novaderrik
Well-Known Member
- Joined
- May 12, 2004
i believe the turbo cars used the regular production 3.8 block and heads up to 85- but with a different crank, pistons, cam, and induction setup on it.
not sure about the 86-87 cars, tho.
not sure about the 86-87 cars, tho.
The decks are the same on any given year turbo or not.
Really??? if you mean all the 3.8's are 3.8 and they all have 6 cylinders, then yes. But a given year all blocks the same? Hardly. 109's the same, yes. But I doubt that 85 cutlass has a 109 block. Not even the 84 and most 85's 109's.
the 84/85 blocks have thinner (not shorter) decks and the valley webbing in the older blocks is significantly different, rendering it a bit weaker than 109's.
Take a look:
http://www.gnttype.org/techarea/pictureguides/blocks/blockguide.html
If you read my post carefully then you wouldnt have posted. I never said an 85 had a 109. I most likely has a 140. I posted that the blocks are all the same for any given year. Yes, thats correct ill say it again. All the same for the same year if RWD. all 83 are the same. all 84 are the same, all 85 the same(except when they switched to 20 bolt late 85 but the NA and turbos still shared the same castings at the same time of production), all 86 are the same, and all 87 are the same. I never mentioned anything about the deck thickness either. Im not sure about the thickness but id specualte they vary quite a bit block to block. I stated the pre 86 (109) had taller decks which they truly do. The older blocks are not significantly different than the 109 either. The main webbing area is nearly identical. Which is where they fail. Ive never seen one break in the valley area on any year (or any make of engine for that matter) unless it had water freeze in it. They are not proven stronger than earlier blocks either. They all seem to fail the same way from cracks on the main stud threads (usually on the left side) up through the main webbing into the cam bore. Nothing in the valley area. My stage 2 looks like a pre 109 in the lifter area so i guess its weaker than a 109
. Its funny i could probably trade it for 10 good 109 blocks. Its what you cant see that usually counts:wink: .If you read my post carefully then you wouldnt have posted. I never said an 85 had a 109. I most likely has a 140. I posted that the blocks are all the same for any given year. Yes, thats correct ill say it again. All the same for the same year if RWD. all 83 are the same. all 84 are the same, all 85 the same(except when they switched to 20 bolt late 85 but the NA and turbos still shared the same castings at the same time of production), all 86 are the same, and all 87 are the same. I never mentioned anything about the deck thickness either. Im not sure about the thickness but id specualte they vary quite a bit block to block. I stated the pre 86 (109) had taller decks which they truly do. The older blocks are not significantly different than the 109 either. The main webbing area is nearly identical. Which is where they fail. Ive never seen one break in the valley area on any year (or any make of engine for that matter) unless it had water freeze in it. They are not proven stronger than earlier blocks either. They all seem to fail the same way from cracks on the main stud threads (usually on the left side) up through the main webbing into the cam bore. Nothing in the valley area. My stage 2 looks like a pre 109 in the lifter area so i guess its weaker than a 109
Read it, just misinterpreted what you were saying. But thanks for the lengthy dissertation.
550hp with no detonation seems to be the safe limit for stock caps. With girdle or caps they seem to be good to 700-750 hp with no detonation. Beyond that the cost really goes up from other parts needed like a steel crank and rods. Crank and rods are advisable anyway since they are more readily available and cheaper than they used to be. The cheapest thing to do would be to find a turbo short block and just run that. Id run JE or Diamond forged pistons and some K1 rods since you are going to need pistons anyway if you want to convert the NA short block . There is a lot of debate about non rolled radius cranks not being as strong as the rolled radius ones but i wouldnt be too concerned about it running into the tens. As long as the tune is good and there is no detonation.
kingots2004
Member
- Joined
- Nov 6, 2007
you can get an 87 109 block for 200 to 300 hundred dollars thats cheap just incase there is a difference and it will have the oil drainback also.
Or a shortblock out of an 84-85 Turbo car for $400-500. Ive got one if your interested.
Thanks Again !!
Thanks Bison, but i'll probably keep the N/A block if i can help it, i probably won't be going much over 500HP if I can get in mid to low 12's i'd be happy. I was looking at T/A performance's web site, they seem to have alot of buick parts,is there any other vendors that have a good selection of 3.8 goodies?
Thanks Bison, but i'll probably keep the N/A block if i can help it, i probably won't be going much over 500HP if I can get in mid to low 12's i'd be happy. I was looking at T/A performance's web site, they seem to have alot of buick parts,is there any other vendors that have a good selection of 3.8 goodies?
Yes the internals are different and i wouldnt try and pressurize one. The NA pistons are crap. They dont have enough meat in the the top and are very failure prone and are likely to grab the wrist pin from all the heat that will build up in the top under power.
Mid to low 12's will only need about 350-360hp.You will spend a lot more building an NA engine.