Multiple Spark Discharge Boxes

[Steve61BT7]

I am having some trouble with preignition "ping" on my 61-BT7. I shaved the head when I rebuilt the engine and made some other mods. I used some 110 octane racing fuel last month and it eliminated the ping entirely, but I can't stand the inconveniende and $3.50 per gallon. I tried retarding the timing - that helped but the performance was sluggish. Doesn't and MSD box claim to stop this problem? Any feedback would be appreciated.

 

[Devin]

Originally posted by Steve61BT7:
I am having some trouble with preignition "ping" on my 61-BT7. I shaved the head when I rebuilt the engine and made some other mods. I used some 110 octane racing fuel last month and it eliminated the ping entirely, but I can't stand the inconveniende and $3.50 per gallon. I tried retarding the timing - that helped but the performance was sluggish. Doesn't and MSD box claim to stop this problem? Any feedback would be appreciated.

Have you tried any over-the-counter octain booster?

Devin

 

[rjhco]

MSD is not designed to eliminate ping. It may help in some cases but it's primary function is to more completely burn the air/fuel charge by ionizing (firing the spark) multiple times.

I suspect that your distributor may not be properly functioning. Check your vacuum advance and the springs and weights in the distributor. Something may be frozen up causing you to have to advance the entire distributor too much at idle.

Is the car overheating? Maybe the carbs are too lean. That can cause pinging, lack of performance and overheating.

Do you know what compression ratio you finished up with? Are you using a stock head? How much was milled off the head/block? Did you change pistons?

Best regards. Jim Hockert

 

[Jagdreamer]

I doubt if this is your problem if you just had head work, but sometimes excess carbon on the tops of the pistons can cause pinging too. Have you tried runing some top-end cleaner through it?

JD

 

[Devin]

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by rjhco:
MSD is not designed to eliminate ping
Best regards. Jim Hockert<hr></blockquote>

Hate to sound ignorant, but what, exactly, is an "MSD?"

Devin

 

[ajsajs]

MSD stands for "Multi Spark Discharge" The system provides a burst of sparks at the plug versus the single spark given by points or eddy current systems.