6-71 or 8-71 on a 440??

[arizona satellite]

I need your wisdom,:headbang: I have decided to take the plunge and install a supercharger on my satellite and I am not sure what size to go with:eusa_think:, I have a fairly stock 440 w/ steel crank and 6 pack rods. this will see mostly street use, so it does not need to be a full tilt blower. input please

 

[lewtot184]

i'd think a 6-71 is more than enough. if it ain't just change the pulleys and make it what you want. your real issue is a stock bottom end. the two bolt caps won't hold up with a lot of psi and steel rods beat the snot out of whats left. stock type cast pistons are death. i would think a good reliable blower motor should be built for its specific purpose.

 

[tazxprs]

Not only do you need to have a good bottom end but you need to research cam choices.

 

[Pro Street Belvedere]

You will need a blower cam, lobe degree is different from a normally asperated motor and piston compression should be 8.5:1, also blower carbs.
Typically a big block uses 8-71 small block 6-71

8x71 up to 568 cu in
6x71 up tp 426 cu in

This is just a guide line, street purpose 6-71 is fine. I have a 8-71 Hampton on my 440, steel crank, six pac rods, under driven, two 750 holleys, 510 cam.
So far no problems. You can't beat the blower WOW factor at the cruise nights.............I guess if it was on a Hemi :headbang:

Good Luck!!

 

[arizona satellite]

I spoke to Bill dyers and he recomended the 8-71 for use with my combo and for a eng running 93 pump gas he said the mopar 509 purple shaft. boost should be no more then 5-7 psi with a stock bottom end. I think I will stud the mains and heads though just for the added strength.

 

[tazxprs]

Wow! A 509 cam has 76 degrees overlap! I'm surprised he suggested that much. I just happen to have one that was in my 451 for a couple hours.
Too much for the combo I'm trying. Dyers has been around for a while so maybe he is right.

 

[hemi duster]

blower build

I am in the middle of a like build also,,,, I have an 871 mooneyham blower and a 1976 rv block with a cast crank... this is my first blower motor and Im trying to make it very streetable... Infact I live in california and I want to drive it to las vegas for mopars at the stip next year...

Everyone that I have spoke to said IT CANT BE DONE,,,, I beleive that someone has build a street blown 440 that can drive from california to nevada..

but so far I am only adding a victor set of heads, steel crank to 512 cubic inch motor, and not sure of the cam,,, I will follow one of the members suggestions and run 2 x 750 holleys and see where that gets me,,,, my builder is trying to get me to buy race tec pistons,,, whoever they are,,, lol.. I was told to underdrive 10 under and use 7-1 compression,,

 

[Hemi Rebel]

8-71. Or bigger. The smaller the blower the harder it has to work to achieve the desired air flow. The harder it works, the more heat it will produce. If you dont already have them, a switch to aluminum heads would be a real good idea. And the biggest rediator you can find.
There is a guy with a blown camaro that shows up to the local hanhouts around here. His radiator has to be 5 or 6 inches deep. I need to ask him where he got it from.