[4 Jaw Chuck]

Another explanation is called spark scatter, high cylinder pressure causes a higher load on the ignition system which can cause the coil to delay or jump across the plug gap only after the mixture self detonates.

High compression ratios combined with weak stock style ignition systems are a deadly combination, my bet is this phenomena you are seeing only occurs under load above a certain rpm...if so you are getting a clue of your ignition system weakness.

A good test is to physically lock the timing at a high initial like 18 degrees and repeat the test on the dyno, if your still seeing it assume your ignition system isn't up to the task and needs upgrading.

[robertalive]

no its just if the cam was dialed you have advanced the engine.so the ignition is just tuning the spark timing.i was allways taught the distributor is the moved bout an inch to a inch and a half prior to the spark of the .so if the #1 spark connection on the distributor is moved to spark bout an inch or so of travel before it lines with its own cable headed out to the #1 spark plug.so the spark is fired then by the time it shoots out to the spark plug ,it has occured ,if it went off at the same time of the distributor #1 being lined up to spark plug #1 it would be to late and the engine wouldnt run.i didnt understand the timing in that engine changing as the rpm raised.i allways buy the best i can afford in equipment and follow the instructions and research on you tube and internet and never once ran into that problem.i helped build a 65 mustang we built and now did a chevy 350 vortec 4 bolt main ,1 piece rear seal.just a 350 sbc but never bore to 60 for heat problems,i try to stay at .030 maybe .040 but even that i dont know cause you alter one part to much and then it starts throwing you Off in other areas.so i just port and polish the heads maybe 1mm off the exhaust chambers to wake it up,dont want my headers overlapping a 1.5 or 1 5/8 primariey.i really get technical bout the bowls ill just buy a pair of junk valves and port like any of us would go ahead and do.want he bowls like mirrors,mirrors i tell ya.lol .hope that cleared it up a little.sorry for confusing the masses.lol.if it makes sense and you wanns motor chat with ,hit me back anytime.bye dude

[cool rockin daddy]

Can somebody please translate the above gibberish?

[2x4 Barrels]

Hi guy`s

Is it possible that voltage rise time is the real issue.What I mean is hei pick up voltage will rise with r.p.m. and alter timing.


2x4`s

[T-bucket23]

If you want to prove if it is mechanical or electronic it is simple and has been stated in this thread several time.
Disconnect the vacuum advance
Lock the timing at something reasonable and see if it still jumps.
If you lock it and it still moves then it is not the advance weights or related parts. I would then look at the module or pickup. Either could cause the issue. A bad pickup may not be up to the rpm task and could be collapsing the field a little to soon at higher rpm or not building the field long enough. I would also check the air gap on the pickup it becomes more critical at higher rpm. The module could also be an issue but the pickup would be my first guess if it is electronic.
I think if the timing chain was stretching you would be loosing timing not adding and it would be inconsistant.

[Custom10]

Originally Posted by cool rockin daddy

Can somebody please translate the above gibberish?

I see the word bowls used allot, I am thinking the bowls are ablaze

[2x4 Barrels]

Hey 10

Check out these bowls out.of course you have look at them upside down



2x4`s

[Old Fool]

back in the day a distributor was put on a distributor machine and had its advance curve set. no guessing, no oh ****s, you knew what you had. That was before they became dizzy's.

[Greg T]

Today, I use the MSD E-Curve. Worth every penny.







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