detonation / knock issue on 340

[G70464]

View attachment 1715922119

my intake

That will work for a thermoquad
Just seal up the fuel wells with JB Weld Marine and set the floats to. 1 inch and you can go rock n roll.

 

[Babyblue66]

People have run much more than that and there are other factors involved than just cylinder pressure.

240 psi on pump is possible when you know what you're doing.

Not on an open chamber 50 year old Iron cylinder head.
.

 

[Babyblue66]

It can still detonate in the higher RPM range as cylinder pressures increase.
It's harder to hear and diagnose.

It doesn't ping at all anymore.

 

[ir3333]

You don't always hear it. How the car pulls is a dead giveaway.It will be very obvious going from 89 to 94 if there is an issue.
It will just pull harder and smoother on the more stable high octane!

 

[shimsham1]

after way too much thought i decided to order a quick fuel slayer 600 carb (P/N 793-SL-600-VS ) its arriving tomorrow and ill let you all know how it goes after the install. i really appreciate all the advice, opinions & help from everyone.

 

[shimsham1]

Heres the update. installed the carb - quick fuel slayer 600 vac 2nds - a few minor adjustments were needed out the box ( float levels way too high & mixture screws ) took it out for a test and and instantly had 90% less knocking.
stopped and filled up with 93 - while at the gas station retarded the timing. issue resolved. runs like an animal and no detonation.
I really want to thank everyone for their knowledge, ideas and opinions. seems as it was the carb base crack all along.