Pinging

[Zepman]

Hi all,

Over the years I have noticed a few ocassions of slight "tinkling" under very heavy load in first gear on very hot days - it's rare but annoying, I am sure it's when the secondaries come in - Holley 4150 750 double pumper, manual secondaries. SB big cam, polished/ported, dyno'd at 415hp.

Noticed it again today (82F) after a few hard accelerations, adding a couple of gallons of super-unleaded (still E5) helped a little. I guess it's pinging/pinking - running lean, so I need more octane or richness, perhaps timing, can I fit larger jets in the secondaries to cure it? and any "how to's" out there, I've never taken my carb apart as it runs so sweetly normally.

I will run exclusively on super unleaded (97/98 octane) from now on but would an octane booster help?

Cheers

[502wingman]

in my humble opinion there are three choices depending on your preferences:

- adjust your timing
- try octane booster and calculate if it is cheaper or simply use
- high octane fuel

[Zepman]

Thanks Peter,

I'll try all three. Couldn't make PC this year, for many reasons but will be there along with Martin and the others in '22.

[502wingman]

Same here bro. We only went Saturday night for the ceremony in memory of Wolfgang. It was so sad and I am still devastated.

[Zepman]

Hi Peter,
I've done all three and pinging gone, I think mainly due to retarding the timing a few degrees but not too far to reduce power, still pulls like a train.

See you in PC next year and we'll have a toast to Wolfgang