Hippy396

Hey guys, been messing arround with my 94 LT1 motor, info to hand is hard to come by for these in the uk. What is the correct degree of ignition timing for my motor? Its back to carb and electronic dizzy now. I got it as close as i can by ear, but would like to know an official or prefared adjustment.....

Cheers.

moehorsepower

iTrader: (3)

Timing at what? WOT, idle,part throttle, any mods to the motor..It doesnt matter if you run a dizzy, the timing is basically the same..

Hippy396

correct ignition timing at idle, how many deg before tdc etc.

moehorsepower

iTrader: (3)

Stock motor? and I guess you are using a timing light? you taped the balancer with timing marks correct..I will send you both for a modded & stock motor...

96capricemgr

iTrader: (1)

The stock damper hub is not keyed so I would strongly recommend a keyed hub before you go trying to get this sorted out. I really wouldn't expect the stock hub to move but if it does it will create never ending headaches.

Few folks actually check their computer controlled LT1s with a light and I expect there is some variation between what we tell the pcm and what the motor actually gets. I know the pcm adds some timing beyond what you program based on rpm.

moehorsepower

iTrader: (3)

^^ Yup, Don't know what they use up there, software or the ole timing light method..

96capricemgr

iTrader: (1)

I have never put a timing light on my car but I do know that with a programmed max of 29 at high rpm/WOT the datalogging software reports more like 32 or so. I never really fixated on it just played around up and down looking for best performance. So I guess I am assuming the pcm adds some timing and the dataloggger reports it but I suppose it is possible the datalogger is wrong.

OP I do not necessarily mean for you to look for the same max timing I am using, I have a pretty potent heads/cam fair bit more compression than stock and 93 octane, making a whole lot more than stock power so what number you need to use might be completely different.

Hippy396

the previous owner seems to have left some tipex timing marks on the damper but ...im goin to double check to make sure they are correct. There is no pcm on this car at all, its all back to bare basics. the motor is supposed to be taken out to 400ci, no idea if its true or if a cams been used. when i got the car, the motor ran crap, bogged down and backfired when ya booted it. Found the edlebrock was worn out and the headers possibly came off a pick up sbc as they were so long they had hit the floor and restrictivly flattened the bottom tubes out, i put a holley 750dp and hooker super comps on and transformed the car. Just curiouse about the ignition timing as ive messed round with the dizzy and got it close as i can by ear, but would like some ideas what it should be at idle with my timing light. Cheers.

LT1Altered

iTrader: (3)

Disconnect and plug vacuum line (if you're using one), hold engine at 4000 rpm, set timing to 34 degrees.
Shut engine off, reconnect vacuum line, set idle to where you want it.
That should be a good starting point.
You can play with setting it anywhere between 28 and 40 for maximum horsepower but depending on your compression ratio and what kind of gasoline you have, it might be best to limit the timing to a maximum of 34.

FAD2BLK93

I have set all my cars to. 16 degs at idle with 36 being WOT. Good bottom end off the line.