4.3L Vortec Block Limits

MCH86GN

Well-Known Member
This question has been beat to death with regard to 109 3.8L block for Turbo Buicks. but what is the max hp with 4.3L Vortec block found in the sy/ty. Completely stock and built with forged pistons and rods if they make them. A nitrated crank and steel 4 bolt mains caps.

I have seen a Syclone run in the 8s, but I found out that it had a Chevy Bowtie v6 in it. I guess the bowtie is similar to the Buick stage II blocks.

I don't own a sy/ty, but I'm still curious.
 

MCH86GN

Well-Known Member
Anyone? Anyone? If someone has a roller and lots of money, you should buy the LV3, the new pushrod 4.3L v6 and slap it in the a sy/ty. It comes with a forged crank, 6 bolt mains, thick main saddles, I think nodular iron main caps and a billet roller cam.
 

proptop

Active Member
Don,t know what kind of power they will take as I have yet to find out. But I will tell you at over 30 lbs of boost the crank will flex and tighten up the mains and knock out billet main caps out of the block. I am still waiting to put motor back toghter for round two,
Bob
 

MCH86GN

Well-Known Member
Don,t know what kind of power they will take as I have yet to find out. But I will tell you at over 30 lbs of boost the crank will flex and tighten up the mains and knock out billet main caps out of the block. I am still waiting to put motor back toghter for round two,
Bob
Ouch! Did/does it have a stock crank? Is there an aftermarket forged crank for the block? From my understanding, the block can be drilled such that it will support 4 bolt mains.

Interesting, I was talking about putting a girdle on my 3.8L block and one of the vendors on here said you'd be better off with a forged crank. At least for the 3.8L and 4.1L block, the forged cranks have came down in price quite a bit.

What turbo are you running? Do you have the stock intercooler setup or an aftermarket air to air IC?

Have you considered a chevy bowtie or are they too expensive or are your goals something else? As in getting the most out of the stock block?
 

proptop

Active Member
Stock crank, good crank alot of money. All billet main caps. Stock/modded intercooler have an air to air not sure if I want to install it. 64/66 Gen 2 PTE Turbo with a buick flange and downpipe/external gate. Thinking about using turbo on my Buick and detune truck as it is a real PITA to work on.
Later,
Bob
 

CC801

New Member
This question has been beat to death with regard to 109 3.8L block for Turbo Buicks. but what is the max hp with 4.3L Vortec block found in the sy/ty. Completely stock and built with forged pistons and rods if they make them. A nitrated crank and steel 4 bolt mains caps.

I have seen a Syclone run in the 8s, but I found out that it had a Chevy Bowtie v6 in it. I guess the bowtie is similar to the Buick stage II blocks.

I don't own a sy/ty, but I'm still curious.

That 8 second truck has 20k plus in a long block, bowtie parts are all discontinued and people charge a huge price for them. The only cranks available are about 3k alone. But to answer your question stock blocks have lived at 800 hp with 4 bolt mains , quarter block fill, and studs. Rods are available eagle makes decent ones. Pistons are same as a 350.
 

MCH86GN

Well-Known Member
That 8 second truck has 20k plus in a long block, bowtie parts are all discontinued and people charge a huge price for them. The only cranks available are about 3k alone. But to answer your question stock blocks have lived at 800 hp with 4 bolt mains , quarter block fill, and studs. Rods are available eagle makes decent ones. Pistons are same as a 350.
The truck I'm making reference to, I was told it had a bowtie. Is that in fact the case?

I don't know the if it was because of the 109 being out of production or politics, but it would have been nice for GM to have used the 109 block in the Sy/Ty.
 

NJTy180

Typhoon Member
I don't know off the top of my head what the limits of a stock block are, however the stock crank can only handle 600-650 HP before you start having serious issues.

Any other crank thats available will cost at least $2500 and I've seen people mention wait times of 4 to 8 months just to get one.

in 16 years I can't recall anyone posting about a block failing. Its always crank/rod issues or head gaskets when you start making serious power.
 

MCH86GN

Well-Known Member
I don't know off the top of my head what the limits of a stock block are, however the stock crank can only handle 600-650 HP before you start having serious issues.

Any other crank thats available will cost at least $2500 and I've seen people mention wait times of 4 to 8 months just to get one.

in 16 years I can't recall anyone posting about a block failing. Its always crank/rod issues or head gaskets when you start making serious power.
Interesting. Dusty Bradford ran the stock 3.8 block into the 5.9x in the 1/8th and when he hit the 5.8x range the block cracked in half. Sounds like no one has ever really pushed the limits of the 4.3 block with a stronger crank and splayed 4-bolt main caps. Interesting that the 3800 series 2/3 block has made about 800rwhp with the stock crank and main caps. That's pretty damn impressive. Like the 4.3l the forged/billet crank for the 3800 series 2/3, it is an expensive piece. If people can reliably make 800rwph with the stock crank and main caps, no sense in going to a forged/billet piece. However, it would be interesting to see how far these blocks would go. That means someone has to build and push it to it fails. Not many willing to that.
 
Last edited:

bison

Moderator
Staff member
The truck I'm making reference to, I was told it had a bowtie. Is that in fact the case?

I don't know the if it was because of the 109 being out of production or politics, but it would have been nice for GM to have used the 109 block in the Sy/Ty.
Why? They were onto the first generation 3800 which is better than any of the prior production blocks.


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bison

Moderator
Staff member
I don't know off the top of my head what the limits of a stock block are, however the stock crank can only handle 600-650 HP before you start having serious issues.

Any other crank thats available will cost at least $2500 and I've seen people mention wait times of 4 to 8 months just to get one.

in 16 years I can't recall anyone posting about a block failing. Its always crank/rod issues or head gaskets when you start making serious power.
The same thing with this community until better tuning tools and knowledge of the engines limitations were better known.


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MCH86GN

Well-Known Member
Why? They were onto the first generation 3800 which is better than any of the prior production blocks.


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Because the LC2 was ready to be dropped in, you're well aware that the prototype Sy used an LC2.
You would think that the 3800 blocks wouldn't have been as strong or stronger the 3.8l, considering the initial 3800 blocks were all for NA applications. Had I not started investing what will turn out to be $20k in the 109 and 200 4R combo, I would've definitely went series 2/3 build. Spent the money just to try and build a reliable 10s GN and I'm told it's still a gamble because I spent $10k on a 109 junk block. That hurts. I do have a fully machined 3800 series 2 block with mains. Maybe I will built another car around that.


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bison

Moderator
Staff member
Because the LC2 was ready to be dropped in, you're well aware that the prototype Sy used an LC2.
You would think that the 3800 blocks wouldn't have been as strong or stronger the 3.8l, considering the initial 3800 blocks were all for NA applications. Had I not started investing what will turn out to be $20k in the 109 and 200 4R combo, I would've definitely went series 2/3 build. Spent the money just to try and build a reliable 10s GN and I'm told it's still a gamble because I spent $10k on a 109 junk block. That hurts. I do have a fully machined 3800 series 2 block with mains. Maybe I will built another car around that.


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With the correct tuning tools 10's are not a struggle these days


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MCH86GN

Well-Known Member
With the correct tuning tools 10's are not a struggle these days


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I'm looking for low 10s in car that weighs around 3800 with me in it.

Bison have you ever worked on sy/ty in any capacity.
 

bison

Moderator
Staff member
I'm looking for low 10s in car that weighs around 3800 with me in it.

Bison have you ever worked on sy/ty in any capacity.
Not in comparison to Buicks and Fords. Low 10's/3800 lbs for longevity is a lot to ask of a production block.


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bison

Moderator
Staff member
I'm looking for low 10s in car that weighs around 3800 with me in it.

Bison have you ever worked on sy/ty in any capacity.
Not in comparison to Buicks and Fords. Low 10's/3800 lbs for longevity is a lot to ask of a production block.


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MCH86GN

Well-Known Member
Not in comparison to Buicks and Fords. Low 10's/3800 lbs for longevity is a lot to ask of a production block.


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Well that's at the track, just cruising I will never be at that power level, and maybe if I do achieve I won't try again. Who knows at the track I may get thrown off if I run into the 10s, lack of safety eq.


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proptop

Active Member
Block will split about 750 if it is not filled/hard blocked as I just found out. Time to put the Bowtie setup in.
Bob
 
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