SBC 265 & 6-71 Blower

Has anyone ever put a 6-71 blower on a SBC 265? If so what sort of underdrive ratio did you use to get somewhere in the range of 6-8 psi of boost?

 

Well, I dont have a direct answer to your question but I'm sure you can find more info under the topic third gen camaro supercharged 305 tpi motors. 305s and 265s share the same bore. Think of a 305 as a stroker 265 lol!

 

my 6-71 at 1:1 on a 454 makes 7 psi....i think you'd be happier with a 4-71

 

Wouldn't it would depend on the compression ratio? Look on www.blowerdriveservice.com they have the charts to get you close. You'll have to extrapolate a litte. I have a 283 with a 471 and 76CC heads on it. It make 8 -10 psi at wot and it is driven 1:1

 

I agree with Squirrel, 'cept a 4-71 manifold is VERY hard to find. Been looking for 2 of them for a while. And, I know you can put a plate on a 6 manifold but it just looks wrong......

 

Once again...Squirrel is correct...that small inch engine doesn't need a 6-71.. you have to turn it so slow...a 4-71 like TUDOR is running will do you just fine.

 

I should add that this is a small bore 6-71. The problem with all the drive ratio boost charts is that none of them agree between others. I have looked at several different websites and none of them agree.

 

I run a 671 on a 276 ci flathead with 7-1 heads. I run 20% underdriven. At 5grand it is showing 15lbs on the gage. That is not true cyl. pressure, it is plenum pressure not making it in the intake ports. Plenty for a 3 main motor.
Just run your clearances a little loose on the rotor setup.
I have 35K on the setup with no problems.

 

have you looked into welding a plate on top of an old 4bbl intake?

 

That will work IF the carburetor mounting surface is parallel to the crank shaft or the belt will run off.

 

that's why they make mills?

 

If you want a intake like the one mentioned (4 barrel to blower) PM me I know were one is, I can get you a price and a pic if you want. located in PA
Paul