Carb jetting?
Thread Starter
Melting Slicks
Joined: May 2003
Posts: 2,387
Likes: 2
From: Meriden CT
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
Pro
Joined: Feb 2001
Posts: 558
Likes: 0
From: Dallas TX
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.
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
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
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Safety Car
Joined: Jun 2002
Posts: 4,135
Likes: 1
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
Race Director
Joined: Mar 1999
Posts: 10,258
Likes: 1
From: Calif.
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...
Safety Car
Joined: Jul 2002
Posts: 3,770
Likes: 3
From: St Louis MO
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
Team Owner
Joined: Sep 2003
Posts: 88,393
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From: eville in
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
Burning Brakes
Joined: Aug 2000
Posts: 1,239
Likes: 0
From: NY
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; Jul 16, 2004 at 12:59 PM.
