PERTRONIX Plug Gap?

[Powerhouse]

Hello all, 

 

I have searched throught the posts on pertronix1 with the 40k coil  here and haven't found anything on plug gap being used.  Anyone have an idea on what that might be? 

 

The reason I ask is that I think I have some ping or knock just at the very start of harder acceleration.  I even have the noise temporarily when hitting the gas a bit harder than normal at idle.

 

I had my plugs set at .060 for the (wrong curve)HEI.  I ran the engine at that HEI gap setting when I first started the pertronix...ran fine at idle.  I didn't want to risk anything so I stopped the engine and gapped down to .035. 

 

Pertronix website says ""In most cases increasing the factory recommended gap by .005 improves the engine performance."

 

Any info is greatly appreciated.  Thanks.

Edited January 22, 2013 by Powerhouse

[Don Coatney]

Have you checked the timing? Too much advance will cause pinging / pre ignition. I dont think plug gap has much to do with that.

[Powerhouse]

It is only set at 6 or 7 advanced.  I will try and retard it a bit more.  Does anyone run at TDC?  With todays gas I thought it was not really possible to get a smooth ride.

 

After I posted this I checked the timing and found that it had walked to about 10 advanced.  Must have been a loose hold down bolt. 

Edited January 24, 2013 by Powerhouse

[greg g]

I am running around 5 degrees of advance.  Set by vacuum gauge, then retarded a bit.  I believe that folks have posted that they have set their gaps at .040 with electronic type igitions.  What plugs are you running???

[Powerhouse]

306  I think...I can check after work..but I'm pretty sure.

 

Thanks.

[wallytoo]

i'd take pertronix advice and gap it to .005 over stock.

with hei, even though you can gap plugs to around .060, you really don't need to. use stock, or slightly wider, and you should have pretty decent plug performance.

[steveplym]

I'm running stock plug gap with my petronix ignitor on my 283 Chevy in the old truck.  Had no problems to date, and it has been running that way for about 10 years.

[DJ194950]

Fatory spec gap for plugs are at least for 1950= .028 non resistor, .035 for resistor

I think you are running a resistor type plug. #306 std gap = .035 and per Pertonix + .005 = 0.040 gap

I'm running my resistor plugs #,?? at .035 with a pertonix ign.. I figured the plug make and style would determine the correct plug gap. Opening the gap up to .060 could raise the insulator temp. too high and cause preignition(knock).

I need to read the pertronix spec. again about the =.005 addition.

Always learning is good for the old brain.

Doug

[Powerhouse]

I set my plugs to .040 and timing to 5° advanced.  Seems better now...I may still retard it a bit more to see if the noise goes away completely.  I can still hear it a bit.  Runs nice though.  I gave it a decarboning wih some of that sea foam stuff too.   Seems to have made it better.  I didn't..and will not put it in the crank case.  That sounds like a bad idea.

Edited January 24, 2013 by Powerhouse

[Rodney Bullock]

We are only suppose to set timing at 2degress before top dead centeron the old 6cly. If you have a modified cam then you will have to play with it. on my hot rods with hei I gap the V8 motor plugs to 60 they run better and they run clean meaning they do not have that gas smell. I have the petronics system on my 60 T-bird and my 61 Studbaker hawk. The plugs are gaped to OEM spec's They run great that way. I know sometimes you have to go test it back and forth to get a good motoring feel out of the car.