Carb jetting?
#1
Melting Slicks
Thread Starter
Carb jetting?
Hi all,
I currently have a 383 being built for me at a local shop. I have a Speed Demon 650 that is next to new off my old 350 that I would like to use on the new motor. I am not familiar with carb modifications at all. What should I do? Will this carb flow enough for thid motor?
Thanks
I currently have a 383 being built for me at a local shop. I have a Speed Demon 650 that is next to new off my old 350 that I would like to use on the new motor. I am not familiar with carb modifications at all. What should I do? Will this carb flow enough for thid motor?
Thanks
#5
I use a 650 on my 383, and it works fine. There's a calculator on the web somewhere, and for my displacement engine, it said to use something near 630CFM... 800 is waaayyy too big for a 383, and with a 750, you're going to have tuning issues trying to make it work.
#6
Safety Car
Too big?
Originally Posted by Jasonty
I use a 650 on my 383, and it works fine. There's a calculator on the web somewhere, and for my displacement engine, it said to use something near 630CFM... 800 is waaayyy too big for a 383, and with a 750, you're going to have tuning issues trying to make it work.
Brett
#8
Originally Posted by Brettmc
Brett
#9
Racer
Member Since: Feb 2004
Location: Murrells Inlet SC
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Originally Posted by Jasonty
What? Seriously, 800 is too big for a 383. Unless there's some serious horsepower output from that engine... But I'm curious, tell me what's on your mind...
#10
i was running a 750 on my 383 and it was too big , i switched to a 670 street advenger and i feel its still to rich- the walls in my garage are black with soot from starting the car in there with the 383-with the 750 and i still notice a lot of black carbon from the 670 too
#11
Race Director
Originally Posted by carl a
i was running a 750 on my 383 and it was too big , i switched to a 670 street advenger and i feel its still to rich- the walls in my garage are black with soot from starting the car in there with the 383-with the 750 and i still notice a lot of black carbon from the 670 too
Paging Dr. Grimsrud. Dr. Lars Grimsrud to the C3 Forum...
#12
Safety Car
Originally Posted by The Dude
The short answer is that's a TUNING issue, not a sizing issue. But don't take my word for it.
Paging Dr. Grimsrud. Dr. Lars Grimsrud to the C3 Forum...
Paging Dr. Grimsrud. Dr. Lars Grimsrud to the C3 Forum...
I'm now in the process of tuning my 850 with an O2 sensor. Details to follow.
Brett
#13
Team Owner
Originally Posted by carl a
i was running a 750 on my 383 and it was too big , i switched to a 670 street advenger and i feel its still to rich- the walls in my garage are black with soot from starting the car in there with the 383-with the 750 and i still notice a lot of black carbon from the 670 too
#14
Burning Brakes
Member Since: Aug 2000
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650 is way, way too Small
Volumetric efficiency dictates a 650 for an average engine.
If it's just a 383 with meduim performance heads, mild cam your ok...
other than that you need larger or I'll spank you with my 350 with a 750 Holley
Volumetric efficiency dictates a 650 for an average engine.
If it's just a 383 with meduim performance heads, mild cam your ok...
other than that you need larger or I'll spank you with my 350 with a 750 Holley
Last edited by 81ZZ4; 07-16-2004 at 12:59 PM.