stroker distributor questions

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340sFastback said:
I run my distributor at 34 degrees locked, as in no mechanical timing, and it starts right up hot or cold no problem. I had to run it locked due to 108 LSA cam and 2500 stall converter. It surged in gear when I had it at 21 initial and 34 total. 10.3:1 compression eddie heads stroker small block. Drives nice, smooth, and quiet at low rpms too. Oh, and its a Mallory Unilite very easy to lock or set the curve any way you want. No external box either.
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Do you use a REV limiter?? If so what kind?
The reason I ask this is with my 410 it comes on the pipe very fast, 4spd and I am sure yours does also. If something lets loose or I miss a shift it saves my azzzzzz. Happened the other day bounced of the revv chip at 6800rpm. If I didn't have it chances of it revving to 8k+ before I recovered could have been catastrophic. I dropped a valve and took out a cylinder on my 340 when the same thing happened without a limiter. I run the MSD Digital 6 now.

By the way I recovered got it in 2nd and kicked a 64 GTO's azzzzzzz!! The guy pulled up at the next light and said DAMN that car haul's assssssss. :-D
 
340sFastback said:
I run my distributor at 34 degrees locked, as in no mechanical timing, and it starts right up hot or cold no problem. I had to run it locked due to 108 LSA cam and 2500 stall converter. It surged in gear when I had it at 21 initial and 34 total. 10.3:1 compression eddie heads stroker small block. Drives nice, smooth, and quiet at low rpms too. Oh, and its a Mallory Unilite very easy to lock or set the curve any way you want. No external box either.
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ok...so you say you have it locked at 34* and it starts ,drives just fine.

Then you say..you had it a 21* intital/34* total and it surged?

...IF it was LEAN it would surge/jerk worse getting up to speed being locked at 34*

If the POWER VALVE was blown it would surge/blubber, which a lot of people can confuse for a lean surge if bad enough like when the power valve has a hole in it.

34* locked out might help counter the blown power valve but only if you are running on the leeeeeaaan

I wonder if you are not remembering right ,or forgot, or didn't remember that you actually had too much total?
 
I don't have a rev limiter, mine is an automatic. But you guys got me thinking about one because if something lets loose (drive shaft, trans, rear) this engine will rev to the moon in a split second.
 
daredevil said:
dang i need the same bushing
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I'll make a few and send'em out.

I'm also working on the idea of slot inserts/bushings for the mp units so guys don't have to weld or do something like this that they are either ill equipped for or don't wanna mess with it.

a few other ideas I have a well.
 
1wild&crazyguy said:
ok...so you say you have it locked at 34* and it starts ,drives just fine.

Then you say..you had it a 21* intital/34* total and it surged?

...IF it was LEAN it would surge/jerk worse getting up to speed being locked at 34*

If the POWER VALVE was blown it would surge/blubber, which a lot of people can confuse for a lean surge if bad enough like when the power valve has a hole in it.

34* locked out might help counter the blown power valve but only if you are running on the leeeeeaaan

I wonder if you are not remembering right ,or forgot, or didn't remember that you actually had too much total?
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LOL, I remember, it was just last year. Carb is new Holley 750 DP and I changed the power valve to a lower one in an attempt to help idle. Power valve is not blown, does not run rich. When I had it at 21 initial 34 total it only surged in park, at a stop, in gear. Once rolling, even at a very low speed, the car ran perfect. Brian at IMM, who custom ground the roller cam, helped me set up the carb and distributor. I did what he said and the car runs good now. I also discussed it with Ryan at Shady Dell Speed who said the converter is too tight for the cam but agreed with Brian's recommendations. Again no starting issues with distributor locked even in the middle of the summer when engine is hot. Fires right up. Having distributor locked is kind of nice too, just set the timing at idle and your done.
 
koryliss said:
340sFastback,

I have often wondered about the surging - I have the problem (especially when cold)... can you tell me a bit more about what causes this? Did you have the surging when it was warmed up?

Thanks,
Kory
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See above post for a better explanation about what my car was doing. Sounds like you need to richen up your carb a bit. When engines are warm they don't need as much fuel as they do when they are cold. Sounds like you need bigger primary jets.
 
340sFastback said:
LOL, I remember, it was just last year. Carb is new Holley 750 DP and I changed the power valve to a lower one in an attempt to help idle. Power valve is not blown, does not run rich. When I had it at 21 initial 34 total it only surged in park, at a stop, in gear. Once rolling, even at a very low speed, the car ran perfect. Brian at IMM, who custom ground the roller cam, helped me set up the carb and distributor. I did what he said and the car runs good now. I also discussed it with Ryan at Shady Dell Speed who said the converter is too tight for the cam but agreed with Brian's recommendations. Again no starting issues with distributor locked even in the middle of the summer when engine is hot. Fires right up. Having distributor locked is kind of nice too, just set the timing at idle and your done.
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I'm translating this as ..'.it ran rough and wanted to die in gear at a stop'

so you have too much cam for the convertor, or the wrong convertor.

in other words.. it didn't surge due to too much timing and didn't surge driving down the road, it only surged loaded at idle.

Why not just raise the initial more to 25*? or maybe you did that....
 
The surging could have been a result of not enough preload on the springs with the advance. If the advance started moving right around your idling rpm then very small changes in rpm would cause changes in the timing which would cuase the surging.
 
I tried all kinds of different initial timing settings, spoke with Brian who recommended I lock it, so that is what I did and it fixed it without changing anything else. It works with no bad side effects so I'll leave it. If I ever get a looser converter in there I'll mess with it again.
 
340sFastback said:
I tried all kinds of different initial timing settings, spoke with Brian who recommended I lock it, so that is what I did and it fixed it without changing anything else. It works with no bad side effects so I'll leave it. If I ever get a looser converter in there I'll mess with it again.
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hey, if it starts at 34* hot, then leave it.
thats the right setting for YOUR combo.

you need more compression though.jmo
 
Pete at Best Machine recommends i lock the distributor at full advance. The best thing is the MSD has that option. I figured i will lock it for the initial cam break in and shake down of the car, then see if i have any starter, cranking issues. What, if any, effect does running at full advance have on engine temps, carb jet size, starting issues,(kickback or back fire). I do have a Mancini mini starter and trunk mounted battery for this combo, also planning on an ATI 4500 converter.
 
Finally...something I know a little about. You WILL have starting issues with 34 degrees initial. I promise. Especially hot starts.
Once broken in, find the minimal initial timing that will let the engine idle clean. Then make sure you get a good hot start with this setting. All ya do now is curve it for 34 total and your in like Flint. Mallory makes a pretty good distrib that is waaay adjustable and no vacuum advance.

Now. If the motor still won't hot start at say...25 or 26 degrees you're gonna have to get a spark retard set up.

Remember ANY distrib can be "locked out", but not all are infinitely adjustable. No need to pay a guy to curve your distributor. It's about the only easy thing we can do. Especially if you have to "experiment" a bit.
 
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