Detonation under hard acceleration

just a question, what makes you think you have detonation problems? I ask because Bryant was driving in my car and asked me how long my engine been detonating for. And I'm like, huh? There was some rattling that I heard and always assumed it was something loose in the engine compartment.

 

because when I'm just cruising there is no raddle than when I gun it, it'll rattle from the engine compartment, and I am familiar with the sound of detonation.

O and I went ahead and set the base timing to 8 degrees which resulted in 32 or 34 degrees at 3000 rpms. And I also changed the vacuum advance hose to the other one (left side, ported vacuum). I now need to drive it and see how it does. thanks... now I wounder what octain fuel I'll need. Thanks.

 

I always thought I was having good luck with 87 but I guess I've been pinging my way from one crappy Arco station to another, I may just go up to 89 . . . non-arco!

 

Took it for a little cruise and so far so good, still haven't taken it through the motions of what it usually takes to make it ping, i.e. hard acceleration in 5th gear. Once I'm satisfied with that than I might move onto trying to fine tune the carb again, runs a little on the rich side... ideal to rich on my gauge but most of the time bearly in the rich even at cruise... anyway I'll see what it does on the way to work tomarrow. and I might try 87 the next time I fill up... or should I just go down to 89 and take the cautionary route. thanks again guys.

 

Going to work I still had a little detonation than I remembered that I last filled up with 89 octain gas. On the way home I needed gas and filled it with 91 and there was no detonation. So much for saving money on gas... I wounder what else to look at...

 

does it detinate when floored or when you moderately accelerating?

 

Detonation is caused by compression too high, carbon or sharp edges in the combustion chamber, thin spots in the casting where heat will concentrate or too much advance in conjunction with one or more of the other things.
Try installing a water injection system - it will clean out any carbon while you use cheaper gas. After a tank running through it with water injection see if you still have the problem.

 

I haven't floored it yet, So I'd say moderate accelleration.

So I don't need to look at the plug gap than and their matterial irrelavent. I would need to look into that water injection thing... haven't heard much on it. would water in a spray bottle work? I have run some fuel system cleaner but thats probably not the same. thank you.

 

Hmmm. Not sure what that means. I seldom drive my car without flooring it several times.

I only drive 65, but I get there QUICKLY!!!

I always ran lean on the Edelbrock. I ended up getting rid of it because i ran out of rods and jets to keep it rich enough for my setup.

But I never had detonation issues, as far as I know. ( i AM 35 db hard of hearing, though, so I may have missed it.)

 

Ever sents I got that T-5 installed I've been trying to get my shifting down... so I still keep the throttle on pretty fine control... and I don't like to rev it to high either... so no I really don't floor it...

 

ok now pull the vacuum advance hose off the dist. stick something in the hose to plug it. now try driveing it. if the detination goes away. that means your vacuum advance is advancing to much. they usually are adjustable. if it has a hex shape portion behind the nipple then its adjustable. you stick a small allen wrench in the hole and youll feel it engage the adjuster when you find the right size (mo knows the size because we just did this on his car for the same problem). turn it 1 turn counterclockwise. then test drive. if its gone good job if not then go another turn.

 

I'll give that a shot thanks

 

who's "mo"? thanks

 

never mind its 1/8"... either that or I just twisted something else...

 

mo is mashoi. hes a member on the board who makes lots of posts about his maverick adventures.

so did it work?