Printable View
I have a 1971 350 sbc (double hump heads) with a Demon 625 carb setting on an aluminum high rise, headers, nice cam. It runs great but at Idle when I pop the throttle it stumbles. It smells a little rich at the exhaust. What is the easiest way to tune this carb?
Do you have this document?
http://documents.holley.com/lit701rev10.pdf
Check the accelerator pump. If there is another setting available which would give a bigger squirt try that. If you're running a vacuum advance check the dapshot.
Must disagree with Denny. The aluminum high-rise, dual-plane intake manifold has shown through extensive dyno testing to produce the highest horsepower and torque readings of ANY naturally-aspirated intake manifold being produced today. All it will take, in my opinion, is a little carburetor tuning as offered by Glenn in post #2.
.
What is your initial timing set at? Does your distributor have a vacuum advance? I have found that using a vacuum advance, connected to manifold vacuum, really helps throttle response on a mild street engine. Along with proper carburetor tuning of course.
Had to laugh at this one as it reminded me of a friend who years ago put a Torker II manifold and a 750 DP Holley on a stock 283. We lived at over 5,000 feet as well - what a dog. He burned up a lot of clutches before swallowing his pride and admitting he'd made a huge mistake!Quote:
Originally Posted by DennyW
That said - I've used my share of Performer RPM, Holley, and Weiand dual-plane manifolds with great success - typically with 650cfm Edelbrocks or my favorite - 750 Quadrajets. Zoom Zoom!!
Thanks for the input guys.
An aluminum high rise manifold is a little like saying you have a 3/4 race cam. You either have a dual plane or a single plane intake manifold. Not to be hyper-critical, but a person needs to be specific. It makes a lot of difference.