91hatchgt

I run 13* with 89 oct.. Remember when you change the timing to take out the spout connector at the base of the distributor, set the timine, then plug it back in. You will notice an idle change, but this is how it works.. Don't adjust timing with the connector in!

Tims 88GT

y is that, i never have

stanglx2002

i run mine at 12* and 87 octane

Demon_Mustang

Um, that means you need to redo it, because you want to be adjusting the MECHANICAL timing of the distributor itself. With the spout connector installed, the computer is frequently adjusting the timing ahead a little depending on the situation, so the timing you set is not really correct, you might have it at 12 degrees or 14 degrees or whatever AFTER the computer's adjustments, but you want it to be at those degrees BEFORE the computer's adjustments.

BTW, it isn't set in stone what degrees are safe and with what types of fuel. You'll have to play with it, but I think if you want to keep using low octane fuel, keep it somewhere below 12 degrees, some may get away with 13 or 14, but some would not. You would know if it is too high if you're getting detonation, which sounds like there are marbles bouncing around your valve covers. If you hear detonation, bump it a degree back, and keep doing so until you find a setting that results in no pinging.

88GT40

when you play with ignition timing do you need to mess with cam timing at all?

grabbem88

mine's at 18..........like demon_mustang said there isn't nothing set in stone what it should be or not..
depends on heads,cam,and spark....get it tuned and see what is good,and what's not..

birdman076

Mine is set at 20 but I honestly think the balancer is off. As far as detonation 2 things to remember:

1. Audible detonation is the worst, there is inaudible detonation and just because you don't hear anything does not mean you have no detonation problems. My suggestion is this, when you set the timing and hear detonation back off until you don't hear it anymore then take it an extra degree or two for safety sake.

2. To truely test for detonation, lug the engine. By this I mean put a real load on it, DON'T GET IN THE CAR AND HAMMER IT THROUGH ALL THE GEARS. That is the worst thing to do and could result in a hole in the piston top, bent rod, or worse. To really lug the motor, put the car in 4th gear at about 20mph and accelerate briskly. This will put a maximum load on the motor and you will hear detonation if it is a problem.