Thread: Use a 671 or 871 on a BBC?

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I am going to install a LS6 454 in a 1930 Model A and I have been toying with the idea of using a supercharger. I have had a few people say running a 671 on a BBC will create heat problems. Those same people claim IF I use a 871 blower I will not have heating issues. I clearly realize I WILL NEVER get this to hook up due to being so light nor will I ever use all the power. I just think polished superchargers look killer on early Fords. If running a 871 on my BBC what size of manifold referenced carbs should I be running? I am aware I need to be running 8 to 1 compression forged pistons. I would like to run a hydraulic roller cam with the blower, but do not have a clue as to what size or brand to go with. My motor is currently set up to run in the 2500 to 6500 power range. I am sure some of you knowledgeable guys could give me a HEADS UP as to which way to go. Thanks!

O.K., reading in between the lines, here's my opinion.
A 6-71 is gonna be cheaper to buy than a 8-71 and will allow more room at the distributor.
You don't need lots of power, so keep boost down around 4-6 pounds and heating the intake air won't be much of an issue. A large bore 6-71 will make 4 lbs on your motor at 1:1 and 6 lbs at 5% overdriven.
Starting with 8.0:1 static c.r., 4 lbs will result in a c.r. of 10.2:1 and 6 lbs will result in a c.r. of 11.2:1. Either of these will support pump gas if you build the motor with a good, tight squish of around 0.035" to 0.040".
I'd choose a cam with an operating range of 2,000-6,000 ground on a 110 LDA and use a converter with a stall range of 1,800-2,200 rpm's.
At 6,000 rpm's with 6 lbs of boost, you'll need 1109 cfm.
The formula is CID times rpm's divided by 3456 times boost divided by 14.7 plus 1.
(454 times 6,000 divided by 3456) X (6 divided by 14.7 plus 1)
(788.19) X (1.408)
1109.77
Here are a couple of links to help you figure it out.....
http://www.blowerdriveservice.com/faq.php
http://www.blowerdriveservice.com/recommend.php
And a paper I compiled on superchargers.....
http://www.streetmachinesoftablerock...topic.php?t=81

Originally Posted by stylingZ

I am going to install a LS6 454 in a 1930 Model A and I have been toying with the idea of using a supercharger. I have had a few people say running a 671 on a BBC will create heat problems. Those same people claim IF I use a 871 blower I will not have heating issues. I clearly realize I WILL NEVER get this to hook up due to being so light nor will I ever use all the power. I just think polished superchargers look killer on early Fords. If running a 871 on my BBC what size of manifold referenced carbs should I be running? I am aware I need to be running 8 to 1 compression forged pistons. I would like to run a hydraulic roller cam with the blower, but do not have a clue as to what size or brand to go with. My motor is currently set up to run in the 2500 to 6500 power range. I am sure some of you knowledgeable guys could give me a HEADS UP as to which way to go. Thanks!

The heat problems people are talking about are more likely to accur when the 6-71 is "overdriven" 20% or more.This means you would have to run the engine on race gas or methanol.On pump gas with a 6-71 I doubt this would ever happen.
I would look for a mild street cam.I would run 220 to 230 at .050 and try to favor the exhaust by at least 6 degree's.I would also look at cams that run 110,112 lobe seperation.