Ok, everybody post every method they know of to decrease detonation with high compression engines. Forced induction or naturally aspirated.

Jason

High octane gas! A turbo is a test plant for gas. best off with 110

ok, i'll match that response...

pcv oil drainback system. these systems, available commercially or build-it-yourself, take the vapors out of the pcv, run them through a cool-can type canister, drain the liquid oil droplets into the bottom of the can, and either run the vapors out to a breather or back into the induction system. the advantages are twofold: 1. you don't burn a miniscule amount of your oil, instead, it goes into the can where a petcock can drain it back into the sump. 2. the liquid oil coming out of your pcv has a tendancy to cause detonation.

basically, you take those microscopic oil droplets out of the intake charge and help reduce the risk of detonation.

NEXT!

jason

lower the compression lol sorry rookie engine guy

My nissan has a detonation problem.... (See my piece of shit car post) it isn't exactly a high compression vehicle though..... lol

It's not nearly as exotic as Ugly's drainback system, but grabbing a fistful of distributor and turning it a little always works for me.:) Or better yet...call your local 76 gas station distributor, kick out about 1.2 bajillion dollars for a 55 gallon drum of av-gas, turn the distributor a lot, and invest in a neck brace.:)
Or better better yet...cold-cock the first driver you see with a stereo that's louder than his/her engine, gank his/her system (not that I'm condoning the hitting of women), stuff it in whatever you're driving, and crank it to the point you can no longer hear the knockl!
This last option should also be considered the most desperate. If you've got a high compression engine, the best song you're ever going to hear is most likely the one coming from your exhaust...knock or no knock.:)

Scott

In reply to:

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crank it to the point you can no longer hear the knockl!

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me too, especially with my over-noisy lower control arm on my truck. not only do i not hear it, but i also keep the people outside from hearing it...

well, this is the import section so i wasn't going to mention it, but on D shaped combustion chamber heads with a raised quench area, you can deck the head significantly, put a thicker head gasket in and allow the quench area to swirl the mixture more violently, decreasing the potential for large gas droplets (which will detonate quicker than a good misted mixture).

and for an electronically controlled ignition system, that js safeguard multiple cylinder knock and retard system is the key. if cylinder 6 is knocking, it'll retard #6 but not the other 7. it's expensive though.

i just know these turbo / radical compression import people use other methods, i want to know what they are. too bad 90% of the import racers run 14's and up and never run into that kind of trouble. ever notice how all the import people know that one guy with that psycho build on his acura that runs 10's. but nobody has ever seen him in person...

jason

I'll also go with the high octane also and you can turn back the timing some, if adjustable. I had an experience with one of my VW's running 10.5:1, I switched from single points to dual and my pinging went away. I then switched to a Allison (Now Crane) electronic ignition and it still didn't ping. So I would like to say a better/hotter ignition is also something that should work. Ping can also happen when getting some poor gas from one station and you may have to try a water remover additive to get rid of it. I had this once and no matter how many gas tanks of 91 I put in it wouldnt go away.