Engine Build
Thread Starter
Burning Brakes
Joined: Nov 2002
Posts: 930
Likes: 1
From: Phoenix Az
Engine Build
:confused: My boss wants to build an engine for my 81. He figures around 425hp and about the same for torque. The only thing I don't understand is why would he want to start this project with a 400 block? A tech I know told me 400 blocks were a poor choice because the cylinders are a siamese design? I haven't got a clue about all of this,any insight would be appreciated.My personal choice would be to go with a 4 bolt 350 block stroked to 383,aluminun heads,fairly lumpy cam etc. I'd like 425-450hp and low end torque and power. Not going to 1/4 mile so don't need top end. Any ideas? Thanks a bunch in advance. :cheers: :seeya
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Re: Engine Build (phxraptor)
A lot of people, apparently, in "the know", don't like the siamesed cylinder bores. I am sure there may be some drawbacks, but for a guy looking for torque and a relatively low top rpm range, 17 to 50 cubic inches is tough to give up.
The purpose of that "fairly lumpy cam" is to make higher rpm horsepower. The rpm range you say you don't care about. It makes that higher rpm power at the expense of the lower rpm torque, you say you DO want. The larger bore of the 400 will contribute to the torqe and horsepower, all across the usable rpm range. For a meduim power street engine, and in most other cases, too, "Cubes are King". It sounds to me that you ought to let your boss, "do his thing". If siamesed cylinders are so awful, why does Chevy siamese the cylinder walls on ALL of it's sbc, "Bowtie" blocks? Even the 4.00" 350 bore blocks? Good luck, and...
RACE ON!!!
:confused: My personal choice would be to go with a 4 bolt 350 block stroked to 383,aluminun heads,fairly lumpy cam etc. I'd like 425-450hp and low end torque and power. Not going to 1/4 mile so don't need top end. Any ideas? Thanks a bunch in advance. :cheers: :seeya
RACE ON!!!
Burning Brakes
Joined: Dec 2002
Posts: 947
Likes: 0
From: Middletown N.Y.
Re: Engine Build (CFI-EFI)
Nothing wrong with using 400 blocks . I've built a couple and had no overheating or cylinder bore problems in race and street cars until maybe 700HP+ w/nitrous the #8 and 7 cyl start to distort but thats at extreme applications where a bow-tie block should be used. Build the biggest eng you can afford. I actually have a good machined block for sale. Check C4 parts FS.
