Timing help please

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GeorgeGerhard

GeorgeGerhard

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Good Morning All
I went to Sears today and purchased a new digital timing light for one hundred bucks.
I dont know exactly what I should set the timing at.
I disconnected the vacuum line from the distributor, set the timing light for 10 degrees and moved the distributor until the crank mark aligned with zero.
What should I set the timing for
Here are the specs
1976 440 engine
.030 over TRW pistons L235530 10.17 comp
78cc heads
Mopar purple camshaft 284 duration and 484 lift
Edelbrock performer intake
Brand new Holley 750 vacuum sec
Orange ecu box
MSD 6al

Also I checked the vacuum in drive and 600 rpm the vacuum gage reads 5.5
I believe I need to put a smaller Power valve in the carb??

thank you for ant advise
George
 
With that cam anywhere from 16-22 initial is the norm.

Limit the mechanical in the distributor to hit your total number.

600 rpm is pretty low for an idle speed in gear. I bet it currently drops a couple, maybe 300 RPM, from in neutral to drive.

Get the initial up, reset the idle speed and mix screws, then judge whether you need a different PV. The increase in initial from 10*, will pick up your vacuum reading.
 
Hi George,
what distributor do you have in it? The vacuum isn't bad for the cam, but I agree you need more initial. 10 is a good place to start. Also, the dial back light makes it easy to plot the whole timing curve. That's what Cracked is talking about. You have vacuum advance, which is not used during idle or wide open throttle; then centrifical advance, which is rpm based, and then you have the initial timing. For you, you can ignore the vacuum advance for right now. So you want to see what you have for timing amounts at idle, 1500, 2000, 2200, 2300, 2400, 2500 rpms, plus what the total timing is at 4K rpm. The dial back light helps. Just have a buddy bring up the revs while you dial the light and write down the readings.
 
That was where Cracked was headed... The stock type distributors need a little set-up to be considered "performance". One of the mods is to limit the amount of centrifical advance so you can run more initial without negatively affecting the total figure (pushing it too far advanced).
 
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