I have a 383 Stroker (442 CID) - 10.5 compression using Stage 6 (2.14 intake, 1.81 exhaust) auminum heads, solid lifter cam, thorley hedders 6 pac - 411 gears w/pistol grip. 6500 RPM max - msd ignition/distributorI have heard all different initial and final settings. Is there a std initial setup? I have looked around the web and have seen settings from 6-12 degrees initial and 32-38 full advance.Suggestions? I appreciate your help - Thanks....
thmpr93I can see why you are getting so many different opinions. Your 10:5:1 is right on the verge of detonation with 93 octane gas. You can put as much timing in your ride as the gas we have permits. Set your base timing at 12* Your total at 32* have it all in at 2000RPM. If it will take more then go for it 2* at a time. If your using a vacuum advance distributor, set your timing with the line disconnected and plug the vacuum side.Bob
What cam? It will be major factor in the initial ignition timing.
It is a comp cam - gross valve lift .495 - 106 centerlineIntake 35 BTDC 67 ABDCExhaust 75 BBDC 27 ATDC236 duration intake/exhaustLobe separation 110
Thanks for the info - I'm getting ready to head down to the shop this morning. Once we get the initial off-idle bog out of the center carb we will put this on the dyno to get the timing sorted out.
Run 14 maybe 16 degrees initial with that cam timing and it may even help with the off-idle bog.
I would agree with IQ52, depending on how the camshaft was installed, but usually they like more initial timing than stock & even with the Six-Pack/6bbl's, you may have to slow down the advance curve some, with spring &/or weights in the distributor, even if you choose to use the vacuum advance, it will help a ton with tunning, 14*-20* initial isn't un-common at all, it will help with initial lauch too, but hurt you on high RPM's, a max of no more than 38* "ever" more like probably 34*-36* usually, it really all depends on what type & style of ignition/distributor & what type of timing curve, what camshaft, what rocker ratios, where the camshaft was installed @ 0* or is it "retarded or advanced", how much advance is ground into the camshaft already, your actual final compression ratio, how good of a seal you have in the cylinders, what thickness the head gaskets, what cylinder head work done/porting/valve size, weight of the car, gear ratios, trans type, carburetor size style jetts & tune, size of the engine, fuel used etc.... there's allot of different variables to get a good/proper tune-up... good luck
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