Pinging at higher rpm

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6dart9

6dart9

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Got my dart back on the road recently
Noticed a ping at higher rpms
Engine is 340 with msd billet dist and 6am ignition. These are new had mp ignition before
When I had the engine dynoed the best run was at 36 degrees total timing.

I can't remember what springs I put in the dist but it was light just not the lightest

Car is a 4 speed

Looking to get a recommendation for which springs I should run and bushing

Any help is appreciated

Thanks
Justin
 
could be a number of things..


may need to run better gas
could be lean
may need less total timing.
 
6dart9 said:
I can't remember what springs I put in the dist but it was light just not the lightest

Looking to get a recommendation for which springs I should run and bushing
Click to expand...

As far as springs go. What rpm do you idle at? You need to run springs stiff enough to not allow any centrifical advance at idle. Some engines can idle at 700, some need to idle at 1000. The engine that idles at 700 can run lighter springs than the engine that idles at 1000. For the engine that idles at 1000 or above, you have to keep adding a stiffer spring until there is no centrifical advance at idle. (the point is you do not want to use up any advance at idle, and then let it advance as soon as it gets off idle).

When I recurved my 68 340S with a 484/284 cam and idle at 900 with stock mopar electronic ignition. I ended up using the stock light spring and one of the lighter springs from the MP recurve kit and blocked off the vacuum advance. Set the timing to 34° total which then backed down to 17° at idle.

I hope this helps you.
 
Ok
I am running 91 for gas
I will play with the mixtures
I think I need to adjust the timing at idle
I assume if I want total timing around 36 I should do that adjustment when the springs I have in have all the timing in it for example if all the advance was in at 2000 I should time it to 36 at 2000 rpm right?
 
6dart9 said:
Ok
I am running 91 for gas
I will play with the mixtures
I think I need to adjust the timing at idle
I assume if I want total timing around 36 I should do that adjustment when the springs I have in have all the timing in it for example if all the advance was in at 2000 I should time it to 36 at 2000 rpm right?
Click to expand...

whatever rpm the mech advance tops out at.

35-36* should be all you need
 
Black bushing, then time it so it doesn't ping for total if you want to keep it simple.

Medium and light spring should work OK.

If the weather is hot, it will have a greater tendency to ping so slight timing adjustments may be needed to keep it happy. More total when it's cool, less when hot out.
 
Chances are its not all in @ 2,000 rpm.

Back off the timing a few degrees, KB recommend 34 degrees MAX for its hyper pistons.

32 degrees might be all it can get with 91 octane
 
crackedback said:
Black bushing, then time it so it doesn't ping for total if you want to keep it simple.

Medium and light spring should work OK.

If the weather is hot, it will have a greater tendency to ping so slight timing adjustments may be needed to keep it happy. More total when it's cool, less when hot out.
Click to expand...

Sounds like a plan. I messed with it some earlier and got it to ping less. but i will throw the black bushing in because i think this will help
thanks Rob!
 
read through this article.. it may help ya out some...


timing1.jpg


timing2.jpg


timing3.jpg


timing4.jpg
 
Thanks everyone for all the assistance. I think I got it worked out
I got the timing dialed in and rich'ed up the carb a bit and it seems to run way better now
 
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