Timing for a 302

[Fletch189]

I am having trouble timing my motor. I have a 302 crate motor with GT40 aluminum heads 345hp. I am new to doing this stuff but I thought I’d start at 24 degrees without the vacuum advanced. Have a MSP probillet distributor and have not changed anything. Do I need to change any of the springs?

Thanks
Brian

[Excaliber]

Sounds a little low for total advance, but your close. I'd run about 12 deg BASE timing, 14 if you don't any "ping" or hard start conditions. Weights and springs generally change the "curve" of how the centrifigal advance comes on, not the total advance available. Unless you get a "kit" with more clearance on the wieghts and then it DOES change the total advance available. Your smart to leave the vacuum advance out of this, Hook it up when your done!

So total advance to shoot for would be maybe 30-32?

12 plus 18-20 mechanical advance.

Ernie

[turnpike boy]

Ford Motorsport will tell ya 16 degrees initial, 36 degrees total, all in around 2500 - 2700 rpm.

With good fuel you might be able to bump it up to 38 degrees total.

Your MSD has vacuum advance? Check your manual that came with the dist. or call MSD and see what they suggest in the way of stop bushings to place in the dist.

[George Snyder]

Fletch,

I have the same engine in my cobra. I agree with Ernie on the initial timing starting at 12. If you can increase to 14 - 16 without pinging I would try it. If you are like me and are encountering nasty exhaust fumes at idle, the increased timing will help.

If you have not changed the stops in your distributor it should have the factory blue one installed. It is approximately 21 degrees.

Springs are trial and error. I would start by changing from the heavy factory shipped ones to two blue ones. You can mix or match any spring combination you feel has the engine performing the best, but I would also suggest that you start with your total timing all in at 3,000 and then adjust up or down from there.

I am running 14 initial + 21 in at 2700 on 89 octane gas. It seems to be OK. I have a new Demon Carb that I am still in the process of jetting. When that is completed I should be able to fine tune the timing.

Bud

[vettestr]

Timing and more specificlly initial timing is one of my favorite tuning tweeks. As Always the guys who already answered have given great advice. I do most things NXS, try it and see what you think. Engines LOVE timing and more is better until you reach the max of your combination.. I am running 26 degrees initial but other mods also help allow that much timing.
I strive for 15 to 20 degrees initial on most engine combinations but you must also limit total to about 39 /40 max. without vac advance. Adjustable Vac units are available if you want to run it but will take extra tweeking with a high threshold. Knocking or preignition with difficult starting will limit your combo. The hard starting can be eased by stroking pedal 1 or maybe 1.5 times before hitting the key if you are carb'd. Key must be on if injected for enrichment before starting.
Check for pinging by loading when up to normal temp, (at lower rpm put in say 3rd gear at low speed and try to accelerate) listen for pinging. Advance to max until pinging and then retard 2 or 3 degrees from that point as rule of thumb. Be sure to check and limit max timing to 39 degrees and before ping test.
A dial timing light makes this easy but masking tape and a little extra time also works just as well. If your dampner is not indexed you can put tape on dampner and use timing tab to mark an extra few marks on tape and read with new marks.

[bvega]

That crate motor has aluminum heads so you should be able to run 14 degress intial timing easily. Most guys run about 16 degrees initial timing with aluminum heads on 5.0 motors with 91 octane gas. If you live in states with higher octane then up goes the timing advance possible. Try it if you hear some pinging then go back and retard it one or two degrees till it stops. Since you have the Ford Racing motor with the hyperteuctic pistons you DO NOT want to ping often. Those pistons which were used in mustangs starting back in 1993 including the cobra were the crapiest pistons ever made and are very sensitive to pinging. You could easily blow your motor if it pings for an extended period of time. Much more so than pre 1993.