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This question is for the guys actually racing (most likely in AI) or for HPDErs who push their 302s hard. How much advance timing do you run? If the car is not experiencing detonation, is there another reason why you might dial it back?

Background: I've been auto-x'ing foxbodies since 1992. IME, 12-14* was a safe street range, 16* was aggressive but fine with 93 octane, and 18* (or more?) was for those running AL heads with 93 octane. A buddy of mine is arguing that "16-18* is WAY TOO HIGH for most things, except maybe drag racing. The engine will run too hot." Perhaps the tight traffic of a CMC race makes 16* dangerous (lack of airflow to the radiator without hood venting)? Never heard of advanced timing being a drastic reason for engine temps being too hot before, though.

Thoughts?
 

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I don't recall what mine is...I'll have to check again.I'm certain it's nowhere near 15...i think im right at 10. While theres truth to whats said , remember, CMC is limited to a fairly narrow horsepower and torque band so that would limit us cranking it up.
 

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I have a rather "stockish" 302 in my HPDE SN95... I pulled the engine out of an Explorer at the salvage yard, polished the crank, new bearings, drug a hone throught the cylinders and put a new set of rings on the pistons along with a set of ARP rod bolts. I used a Mustang "HO" cam, a set of PAC valve springs and milled the iron GT40 heads .030... I am using a carb and Duraspark ignition system. Essentially, it is an old "CMC 1" engine...

With the vacuum advance unplugged I set the total timing at 32*. I do have a large Griffin radiator and run 93 "pump gas". I have absolutely no problems with detonation and the car runs surprisingly well... At VIR last fall a Porsche owner came by and ask "what do you have under the hood of that thing?" He walked away shaking his head after I gave him a description of the engine and told him I have "about 800 bucks in the entire driveline"...
 

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If the car runs too hot because you're aggressive with the timing, then it's pinging/knocking or you don't have enough cooling capacity. If it's not pinging, it's making power. Backing off on the power level in some attempt to keep it cool seems pretty weak.

FWIW I'm running about 17 degrees with my current combo and I ran about the same with the old iron-head combo.
 

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If the car runs too hot because you're aggressive with the timing, then it's pinging/knocking or you don't have enough cooling capacity. If it's not pinging, it's making power. Backing off on the power level in some attempt to keep it cool seems pretty weak.

FWIW I'm running about 17 degrees with my current combo and I ran about the same with the old iron-head combo.
If MFE is running 17! its time to crank mine up! i think im at 14/15 which felt good going from 10 the car even idles better. My fox runs super cool and shes sporting a stock engine so iron can take some more heat (time to re-time)
 

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I ran 18* with an 86 block (over 150K miles), freshened E7 heads (no porting or other flow work) and a DA1 computer. Mostly street, autocross as often as possible and two HPDEs before the resto-mod started last year. Had some heating problems but that was due to a rad cap that didn't work despite being new. Once that was figured out, no problems. Car's performance even surprised me (a reformed drag racer). I'll put as much static advance into the thing as I can get with no detonation on pump gas.
 

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32 degrees total for me. 10.5:1 347, Twisted Wedge heads, carbed. A little on the conservative side until I can dyno it and find the sweet spot. We endurance race so I'm fine being a little cautious on 93 pump gas.
 

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I dont road race or anything, but I am extremely aggressive at drift events. Had mine around 17*, dropped it to 14-15* and bumped up the fuel psi on the rail. Temperatures dropped after a hard run by about 10 degrees.
maybe it was pinging and I didnt hear it.
 

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Total advance is best kept at 34* max for a built alum head small block Ford, according to Paul Silva ( PSP Racing, one of the pre eminent SBF builders on the planet). He built my current 333 stock block with ported Victor Jr heads, ported Victor intake and Pro Systems 780cfm carb, 10.6:1 comp ratio. Hydr lifters on mech roller cam. App another 50 hp if it was solid roller, but it's a street car. 87 Vert. 3500 lbs, stock suspension architecture and manual steering here, lol.
Here it is at my fave road course, hunting down a new S550.
https://www.youtube.com/watch?v=3_2yTyzbCCQ

We locked out the timing, it runs on 91 octane Shell V power Gold (no ethanol) and makes 444/380 rwhp/tq on a Dynojet. 12.7 @ 114 mph with grandmotherly 2.2 60ft times.

Have run the car HARD (shifting at 6600 on the roadcourse) in 90* humid weather for 30 min at a time. Small power loss from underhood heat build up (no venting yet), 210 H20 temps, 275 oil temps with cooler. 3.73 gear, 25.5" tall 315 Nitto NT01's.

Motor makes power between 4000 and 7000, so the initial advance curve doesn't work for me.

My other motors I ran TTL timing of up to 38*, but that was with adv curves, and without a margin of safety.
 

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ignition timing is dependent mostly upon the combustion chamber, stating xxx amount of timing is optimal is completely inaccurate

here is an mbt reference chart to get you in the ballpark when base-lining your timing, I recommend starting here and playing with it to see what your specific engine likes

MBT Reference Chart / EFIDynoTuning
 

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My bad - should have stated PSP builds (which are usually ported Victor Jr heads) run a max of 34* ttl timing for N/A road race motors.


What fuel is being used: Octane, ethanol % etc.
as the base for your chart?


ignition timing is dependent mostly upon the combustion chamber, stating xxx amount of timing is optimal is completely inaccurate

here is an mbt reference chart to get you in the ballpark when base-lining your timing, I recommend starting here and playing with it to see what your specific engine likes

MBT Reference Chart / EFIDynoTuning
 

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I don't think anybody mentioned it but running a set of plugs one range cooler is a good idea at least my engine guy suggest that I do so in my DOHC.
 

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no its not, its always best to run the heat range plug that pulls the most heat out the chamber and doesnt get the plug too hot

fuel grade doesnt affect MBT, a lower grade fuel just prevents you from reaching it
 

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fuel grade doesnt affect MBT, a lower grade fuel just prevents you from reaching it


https://en.wikipedia.org/wiki/Maximum_brake_torque


Maximum brake torque is going to be determined by a lot more than the combustion chamber design. The entire setup of the each individual motor is going to determine it.
Compr ratio, piston crown shape, effective cyl pressures, FUEL used, and lots more all play a part in this.
 

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https://en.wikipedia.org/wiki/Maximum_brake_torque


Maximum brake torque is going to be determined by a lot more than the combustion chamber design. The entire setup of the each individual motor is going to determine it.
Compr ratio, piston crown shape, effective cyl pressures, FUEL used, and lots more all play a part in this.
Maxing out timing causes increases in plug temps almost more than anything else so colder plugs are required or at least a good idea.
 

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I dont road race or anything, but I am extremely aggressive at drift events. Had mine around 17*, dropped it to 14-15* and bumped up the fuel psi on the rail. Temperatures dropped after a hard run by about 10 degrees.
maybe it was pinging and I didnt hear it.
Tell me more about these extreme drift events you attend.
 

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https://en.wikipedia.org/wiki/Maximum_brake_torque


Maximum brake torque is going to be determined by a lot more than the combustion chamber design. The entire setup of the each individual motor is going to determine it.
Compr ratio, piston crown shape, effective cyl pressures, FUEL used, and lots more all play a part in this.
you completely failed to read my post
 
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