bbc truck pull engine ignition timing

[sspuller]

Trying to figure out were to set timing. Motor is a bbc 492cid. 4.560 bore short stroke 43cc dome pistons RHS 360 aluminum heads cut for 13.6 compression. .800 lift cam 277 283 duration. 1450 carb. Runs 7500 to 8300 rpm at track. I have it locked in at 37 deg. now but it revs quicker and sounds cleaner up high at 47 deg. I haven't run it at track like this but it sounds like it likes it. Can anyone tell me a good place to set it from other similar engines. I cant get to a dyno right now or I would.

[Walter R. Malik]

Trying to figure out were to set timing. Motor is a bbc 492cid. 4.560 bore short stroke 43cc dome pistons RHS 360 aluminum heads cut for 13.6 compression. .800 lift cam 277 283 duration. 1450 carb. Runs 7500 to 8300 rpm at track. I have it locked in at 37 deg. now but it revs quicker and sounds cleaner up high at 47 deg. I haven't run it at track like this but it sounds like it likes it. Can anyone tell me a good place to set it from other similar engines. I cant get to a dyno right now or I would.

What the engine wants when it is heavily loaded is completely different than at a lighter or no load.

Be certain that the TDC reference is exactly at TDC.

[sspuller]

TDC reference is dead on, set it with the heads off. Loads change from one track to another from one end to the other. Makes it real hard to set timing at any point for max power.

[Tuner]

Get one of these from Summit for $165.95 and change the timing on the fly while you're making a pull. Take care, more load = usually needs less timing. Free-rev will always sound better with too much timing for a real load.

https://www.holley.com/products/ignitio ... parts/8680

[MadBill]

Get one of these from Summit for $165.95..

Oops! It's up to $180.95 now, discounted from $201.95..

[sspuller]

Does anyone make a knock sensor that works on a race engine. Something that would have a warning light to use with the msd timing box.

[Tuner]

Get one of these from Summit for $165.95..

Oops! It's up to $180.95 now, discounted from $201.95..

https://www.summitracing.com/parts/msd-8680 $165.95

[NormS]

Your engine is more responsive with 47°, because it probably has more manifold vacuum than with 37° total. I'm afraid you'd kill the engine with 47°, unless your fuel has a boatload more octane than the engine needs. Like Walter said, what the engine likes under load is completely different, than with little or no load. Being that the truck is not competing when there is no load on the engine, I would concentrate more on what it likes when it's loaded hard. 37°sounds much more realistic and reasonable.

[MadBill]

Get one of these from Summit for $165.95..

Oops! It's up to $180.95 now, discounted from $201.95..

https://www.summitracing.com/parts/msd-8680 $165.95

You faked me out with the Summit reference but a Holley link..

[TAM]

Most engines I've ever run on the dyno, including several pulling engines, make best power at 40 degrees.
Your engine may like slightly less or slightly more, but this would be a good starting point IMO.

[MadBill]

Does anyone make a knock sensor that works on a race engine. Something that would have a warning light to use with the msd timing box.

Here you go: http://www.jandssafeguard.com/

[BBCFAN]

Hey OP, did you ever find out what worked best?

I am getting ready to buy a box to run my 499 BB SS NA puller engine.

I am researching pulling timing at high rpm.

[1980RS]

Get one of these from Summit for $165.95 and change the timing on the fly while you're making a pull. Take care, more load = usually needs less timing. Free-rev will always sound better with too much timing for a real load.

https://www.holley.com/products/ignitio ... parts/8680

Wow, $180 bucks? snagged one a new one at the swap meet for $25, guess I will put it on the car next year.