4.1

[1RIPPEN6]

I bought an 84 buick for some odds and ends and did not notice it had a 4.1 until I got it home. Casting #25514291 is this number good or bad?

Thanks

 

[getchasum]

Good block.....Keep her as a spare.

Also if it has the correct crank in her, you scored you a turbo rolled fillet crank as well.

 

[1RIPPEN6]

cool thanks

 

[TrAb]

So the 4.1 did it only come in hotair cars? Why did they make the 4.1 and 3.8???

 

[charlief1]

The 4.1 is an NA engine with a 4 barrel. It was an economy measure for the V8 engines.

 

[TrAb]

The 4.1 is an NA engine with a 4 barrel. It was an economy measure for the V8 engines.

So im guessing this is where the crank comes from for the stroker kits for the 3.8???

 

[dr_frankenstein]

So im guessing this is where the crank comes from for the stroker kits for the 3.8???

nope. same stroke. bigger bore.

A.j.

 

[TrAb]

nope. same stroke. bigger bore.

A.j.

How much bigger of a bore? Do these cars have overheating problems after being bored so much over? Thanks

 

[dr_frankenstein]

How much bigger of a bore? Do these cars have overheating problems after being bored so much over? Thanks

Stock, the 4.1 is at 3.965 vs the 3.80 of the 3.8

there generally not considered street friendly when they have been bored to .060 or more.

But most wont bore farther than .040. there a good block, but have some deck thickness and sealing issues.

A.j.

 

[getchasum]

Do these cars have overheating problems after being bored so much over? Thanks

The 4.1 is Not a bored out 3.8

 

[TrAb]

The 4.1 is Not a bored out 3.8

oooo that makes sense... Think i got it now. So do the heads and other parts fit on the 4.1 from a later model 3.8? Would seem like a good little swap for some...

 

[Ttype6]

oooo that makes sense... Think i got it now. So do the heads and other parts fit on the 4.1 from a later model 3.8? Would seem like a good little swap for some...

The 4.1 is a Siamese block,meaning no water flows between the cylinders. This is why it is able to have a larger bore. All 3.8 parts bolt to it. The 3.8 bores shroud the intake valves of the heads. The larger bores of the 4.1 block relieve this problem and allows the heads to breath better.

 

[charlief1]

The 4.1 is a Siamese block,meaning no water flows between the cylinders. This is why it is able to have a larger bore. All 3.8 parts bolt to it. The 3.8 bores shroud the intake valves of the heads. The larger bores of the 4.1 block relieve this problem and allows the heads to breath better.

Minor correction on this. The RWD 79 to 87 parts will bolt on no problem. The later and earlier parts won't, and the FWD parts are capable of bolting on if it's a very early design. The later ones will physically bolt on but there's no intake that will work from what I've seen unless you want to use an off center stage II carb intake.