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Author Topic:   HP diff, jumping from 2bbl to 4bbl, Steve?
UFnARacing
Member
posted June 24, 2004 08:41 AM
I have a roller 383, about 13:1 that IS cammed for a 4bbl motor. The build cost forced me to run my 4412 on it, but it's a "stage 2" carb. What HP increase could I expect going to a 750CFM 4bbl?

Steve, I ask you because it seems you've had lots of dyno time.

Thanks!

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dirtbuster
Member
posted June 24, 2004 09:31 AM
I would say you could expect about 100HP


nw15
Member
posted June 24, 2004 03:21 PM
what type of heads does your engine have. That will now be the limiting factor if you have good exhaust.


UFnARacing
Member
posted June 24, 2004 03:37 PM
Oh yeah, I forgot that one. I have Vortec's with "some" work done to them. The engine was built thinking a 4bbl would go on, but like I said, I ran out of money for the extras like that!

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xx RACER 96
Member
posted June 24, 2004 10:06 PM
Thats true about the intake I wasnt thinking about that. I had it in my head you had something more like a stock manifold with 2 barrel, but if you were running a victor or something with 2 barrel and switched to 4 then prob wont see 100HP.


UFnARacing
Member
posted June 25, 2004 08:32 AM
Yes, it's a super victor. I elluded to it, but didn't come right out and say it. Everything about this motor is for a 4bbl, but the carb. It's even a 4bbl manifold.

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dirtbuster
Member
posted June 25, 2004 09:35 AM
I would think you would still see prob 50HP since on that combo the carb is the restriction.


bigcityracer
Member
posted June 25, 2004 10:38 AM
Alot will depend onthe rpm you will be seeing!!! 5,500 and under you may only see 20-40 horsepower increase, But if your around 7,500 to 8,000 then you may considerably more. Could be around 60 to 80 pending total combination. A big jump in horse could slow you down if it only increases tire slippage.


nw15
Member
posted June 25, 2004 11:35 AM
Yep probably in the 50-60hp range, not just hp but also torque with is alot more important than hp


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