total timing

[fryedaddy]

how much total timing do i need to run in my 428.i have been told everything between 35-41 from different people.im running cast cj heads,10.7speed pro pistons.,292 comp cam hyd,headers,msd,etc. and what about different fuels,93 vs 110 timing differences.and what about timing for the street vs timing at the dragstrip.im just trying to get the most out of what i have.

[jayb]

38 total is usually a good number with factory cast iron heads.  With race fuel you might be able to go higher; you'd have to check it at the track or on the dyno to know for sure.  If you are running something like 110 octane leaded race gas, you won't hurt the motor if you overshoot the timing a little, so don't be afraid to experiment on the good stuff...

[fryedaddy]

thank you Jay. it does run better with it turned up a little.i have been told not to go above 35-36,so i have been afraid to go higher and try it at wot. but after your reply,i believe i will fill her up with 110 and try 38 or more without being afraid!

[cjshaker]

I can't imagine why anyone would tell you not to go over 35 unless you had aluminum heads with modern chambers. 38* is usually pretty safe with any decent build and decent gas. Any less and you'll be giving up power. In my experience, the older iron heads usually work best around 40*, but that can get a bit touchy if quench distance and fuel quality isn't good. If you run race gas, you'd probably pick up power up to 40*. I mark my intake in 2* increments at the distributor at 38*, 40* and 42*. That way I can change it without having to use a light every time. My iron headed MR made best power at 42*, but I back it off to 40* for street driving. But that's using 93 octane with some 110LL mixed in.

[fryedaddy]

i cant wait to turn that timing up .when i first got this new motor going, i timed it by ear. i must have gotten lucky because it would scoot,quick rpms too.i later set the timing on 35-36,and i noticed it didnt seem to get up and go as good as it was. i didnt want to take any chances with this new engine so i left the timing alone. i have been riding around low on power because of too little timing. im so glad i joined this forum!