flowmaster tech
Active member
has anybody built a staright 8? what kind of hp and tourque can i expect?
straight 8
- Thread starter flowmaster tech
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goose-em
Well-known member
Which straight 8. I am building a straight 6, Pontiac. Stock it had 85 hp, we, my engine builder and I, think we can get around 200 hp.
Changes include, 3/4 ground cam, bored .060 over, milled head .183, larger valves, move spark plug location, relieve combustion chamber, Edmunds intake, custom exhaust, magneto, hardened valve seats.
Stock compression ratio was 6:1, new comp ratio will be around 8:1. Also adding a remote oil filter, stock did not have a filter, not a horsepower boost but will allow the engine to have less wear.
One of the most important things are the pistons. Originals were cast, we are using aluminum. You have to search around a bit and find out what pistons will work.
In the end I really don't care too much about the HP, more important is having an engine that you don't see everyday. With the proper trans and rear end ratio you could run that straight eight all day at freeway speeds.
Changes include, 3/4 ground cam, bored .060 over, milled head .183, larger valves, move spark plug location, relieve combustion chamber, Edmunds intake, custom exhaust, magneto, hardened valve seats.
Stock compression ratio was 6:1, new comp ratio will be around 8:1. Also adding a remote oil filter, stock did not have a filter, not a horsepower boost but will allow the engine to have less wear.
One of the most important things are the pistons. Originals were cast, we are using aluminum. You have to search around a bit and find out what pistons will work.
In the end I really don't care too much about the HP, more important is having an engine that you don't see everyday. With the proper trans and rear end ratio you could run that straight eight all day at freeway speeds.
flowmaster tech
Active member
thats what im after is just the look not a big hp builder.. its the thunderbolt straight8 out of a buick i believe... not sure on the year.. i was just curious on the hp we have a dyno at flowmaster but not sure if ill have time to hook it up.. ill post pics of the motor soon...
R Pope
Well-known member
Buick straight 8 has great torque! Some had dual 2bbls and dual exhausts, look real good. Not a revver, but great in a daily driver.
goose-em
Well-known member
For what it's worth....
Don't stroke the crank, there is little value gained by stroking the crank on this engine, all straight eight Buicks.
Supposed to use solid skirt racing pistons, with them you can get 8.5:1 compression ratio. The stock pistons are crap.
Stock wrist pins are fine, should be a palm push fit.
Port the heads, be careful as the intake ports are thin.
Heads may be milled as much as .175" but you must check clearances to keep the piston from striking the head. For city driving mill the head .100 and use a .015 thick head gasket.
There was a Buick eight that was run on the dry lakes, it had 6 strombergs, milled head, ported and polished, bored over, how much I don't know. It ran around 270 to 280 horsepower.
I have more info on this motor but didn't want to take the space required to put it all in. I am getting this out of a book published in 1952 called, Hot Rod Your Car, published by Wally Parks, Don Francisco and Racer Brown.
This book is hard to find, I searched for quite awhile and found two copies which I bought, they weren't cheap. If you can find it there is a wealth of info in it for Buicks, Fords, Pontiac, Lincoln's etc. Pretty much every engine made prior to 1952.
Don't stroke the crank, there is little value gained by stroking the crank on this engine, all straight eight Buicks.
Supposed to use solid skirt racing pistons, with them you can get 8.5:1 compression ratio. The stock pistons are crap.
Stock wrist pins are fine, should be a palm push fit.
Port the heads, be careful as the intake ports are thin.
Heads may be milled as much as .175" but you must check clearances to keep the piston from striking the head. For city driving mill the head .100 and use a .015 thick head gasket.
There was a Buick eight that was run on the dry lakes, it had 6 strombergs, milled head, ported and polished, bored over, how much I don't know. It ran around 270 to 280 horsepower.
I have more info on this motor but didn't want to take the space required to put it all in. I am getting this out of a book published in 1952 called, Hot Rod Your Car, published by Wally Parks, Don Francisco and Racer Brown.
This book is hard to find, I searched for quite awhile and found two copies which I bought, they weren't cheap. If you can find it there is a wealth of info in it for Buicks, Fords, Pontiac, Lincoln's etc. Pretty much every engine made prior to 1952.
