timing help
Thread Starter
Staging Lane
Joined: Sep 2005
Posts: 68
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From: columbus ga.
timing help I have a 355 with old 327 heads 10 to 1 compression comp magnum 292 cam mallory comp 9000 distributor. My question is I cant get the timing right. I tried to set it at 32 deg. total and it wont even idle. Mallories website says their distributor has 24 deg. built in so when I put it at 8 degs. at idle it dies. It seems to smooth out at about 25 degs at idle but this would be 49 degs total. This seems unbelievable to me. Am I doing something wrong, I understand I have a pretty mild engine but this thing wont even outrun my dads 07 mustang. Its a dog. By the way it also has a new TH400 a 3200 stall and 3.73 gears. The truck is an old drag truck so it is pretty much gutted. So it is pretty light.
best guesses would be it's mostly carb causing the problem, and possibly a vacuum leak.
what kind of carb?
is the cam installed correctly?
are the timing marks on the balancer and timing pointer correct, are you sure 10 degrees you're seeing with the timing light is actually 10 degrees?
the timing is fairly straightforward and you mentioned it correctly- at idle you rotate the distributor so you have roughly 8-10 degrees BTC. Max timing at high rpm with the 24 degrees of mechanical advance provided by the distributor shouldn't exceed 40 deg btdc, the norm is 32-34 deg btdc.
With idle timing set then look at the carb and throw a vacuum gauge on the intake to measure vacuum and then tune the idle mixture from there. Because you say it smooths out with 25 deg BTDC of timing at idle makes me think it's running real lean at idle which can either be the carb idle mixture is way off or vacuum leak.
Also looked up the mallory 9000 and if that's a dual point distributor then once you get the idle figured out the ideal is to set the points with a dwell meter, then reset ignition timing to various base settings of 10 dbtdc +/- a few degrees to see what timing gives best max power without pinging or detonation.
what kind of carb?
is the cam installed correctly?
are the timing marks on the balancer and timing pointer correct, are you sure 10 degrees you're seeing with the timing light is actually 10 degrees?
the timing is fairly straightforward and you mentioned it correctly- at idle you rotate the distributor so you have roughly 8-10 degrees BTC. Max timing at high rpm with the 24 degrees of mechanical advance provided by the distributor shouldn't exceed 40 deg btdc, the norm is 32-34 deg btdc.
With idle timing set then look at the carb and throw a vacuum gauge on the intake to measure vacuum and then tune the idle mixture from there. Because you say it smooths out with 25 deg BTDC of timing at idle makes me think it's running real lean at idle which can either be the carb idle mixture is way off or vacuum leak.
Also looked up the mallory 9000 and if that's a dual point distributor then once you get the idle figured out the ideal is to set the points with a dwell meter, then reset ignition timing to various base settings of 10 dbtdc +/- a few degrees to see what timing gives best max power without pinging or detonation.
