[ronjenkinsdc]

I have a 1967 mustang with an A code 289 4 barrel. I'm running an Edelbrock 600cfm, mild cam, MSD 6AL, stock distributor with points. It runs great, but when I accelerate hard, it makes a lot of 'clattering' noises under the hood. Sounds like detonation on steroids. If I accelerate normally, no problem. If I'm at cruising speed, and punch-it, no problem. It only does this if I attempt a fast take-off. Any help??

 

[Ivy66GT]

Engine knock from either too much timing advance, fuel with too little octane, etc. The same advance at a higher RPM might be OK or its also harder to hear the knock at higher speeds; it might still be there but you can't hear it.

 

[kenash]

"ditto" from my sandbox...

 

[rex1965]

Since you have the stock dist, put your initial ignition timing at 6 btc, and see how the engine reacts, if your pinging is gone, then you can advance it slightly 2 deg at a time and see how it does, if no pinging you can go up to 10 deg btc. Don't advance it any more as your total advance (mechanical + initial) will be too much , if you want more initial advance, get the dist recurved with a performance curve, this reduces the mechanical advance from stock so you can run more initial ignition advance, and changes how the advance comes in, it comes in quicker and then flattens more than the stock curve. This makes a good difference in how the engine performs. My 2 cts. Good Luck.

 

[gibygreen]

This is EXACTLY what seems to be happeneing to my car, And I've done what you've suggested here and more.
Does it sound anything like this? (noise at 0:14).

 

[paul289]

Worst case scenario: Rod or crank bearings are shot. Check your dipstick. If you've struck gold, you've got a problem.