Tuning carb with a vacuum gauge
I read that I could tune my Edelbrock 750cfm 4-barrel carb by hooking it up to a vacuum gauge, is this true? If so, do I hook it up to the 2 ports at the front of the carb and adjust both screws to get the best result? Also, it is recommended that my measurement should read between 15 and 20 in., but I have heavy cam and higher compression (not exactly sure what size etc.) so would I be looking at a measurement more around 10? What do I look for as far as adjusting the screws; i.e. rise or fall in vacuum readings?
Not done yet, stick with me.
Should I attach it to the manifold port, also, at the back of the manifold and check there also? Will the measuremnets be the same? It also has a pressure gauge on the dial.
Thanks again.
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Re: Tuning carb with a vacuum gauge
Hook up your vacuum guage to the intake manifold port of the carb (sucks at idle).
Set you rpm about where you want it to be.
Adjust your idle mixture screws to give you the highest manifold vacuum reading (which should be the highest idle rpm reading with the throttle butterflies closed).
Re-set your idle rpm.
Run it a while and read your spark plugs.
If they are sooty, or wet, then lean it out a bit with the jets and metering rods (strip kit)...
Be super careful to read your instructions with your strip kit because:
a) a little change goes a long way.
b) no one on this planet can read the teeny stamping numbers on those things.
I usually let my technician tweak the knobs.
She is that good! ;)
One small change at a time and you can crispen this carb up real nice.
Hope the info helps.
Jeff:toocool:
Quote:
Originally posted by racerxjj67
I read that I could tune my Edelbrock 750cfm 4-barrel carb by hooking it up to a vacuum gauge, is this true? If so, do I hook it up to the 2 ports at the front of the carb and adjust both screws to get the best result? Also, it is recommended that my measurement should read between 15 and 20 in., but I have heavy cam and higher compression (not exactly sure what size etc.) so would I be looking at a measurement more around 10? What do I look for as far as adjusting the screws; i.e. rise or fall in vacuum readings?
Not done yet, stick with me.
Should I attach it to the manifold port, also, at the back of the manifold and check there also? Will the measuremnets be the same? It also has a pressure gauge on the dial.
Thanks again.
