Knocking

[Reddy]

Hi,
I need some in site on this. My banger sound really good sitting as I speeding up the engine, but if I take it out for a ride it sound good and run strong. But as I running along and I speed it up and put a load on the engine it gets a knocking sound. If I let off it goes away, of just run it easy, no knock, it's just under a load I hear it. HELPPP
MIke

[1931 flamingo]

Where is the spark lever at??
Paul in CT

[Reddy]

I'm running Mallory single point distributors.
Mike

[BRENT in 10-uh-C]

Sounds like the possibility of a loose center main bearing. Have you checked the main bearing clearances?

.

[Reddy]

I did about a year or so, not a lot of miles since I did
Mike

[BRENT in 10-uh-C]

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What were the clearances?

Diagnosing something that someone hears but others cannot is difficult at best. Many noises have been registered in our brains from past experiences where we searched for a culprit and once corrected, we knew what to listen for during the next time. Those various noises have been exposed to me for many, many years. I wish we could be of more help but without something to physically hear, we are just guessing anyway. I do wish you the best of luck. Sorry!!

[Patrick L.]

It only makes the noise when under a load ? It could be spark knock. A Mallory distributor, so I'm thinking it has its own spring and weight advance system ? If so, it sounds as if the advance system needs to be adjusted/changed and/or the base timing needs to be reset.

[Ian in Mississauga]

Please let us know what you find. I've got the identical problem only with stock ignition. I've been working on a spare just in case.

[Duffy1]

Put a stock dist. back in and see if the knock is still there, although if the timing is advanced to far the sound is more like a rattle than a thud,thud knock .

[Reddy]

It is more clatter than thud knock, and it more when it's under load of on a up climb
Mike

[Chuck Sea/Tac]

Originally Posted by Reddy

It is more clatter than thud knock, and it more when it's under load of on a up climb
Mike

That sounds like timing

[gwhite]

Originally Posted by Duffy1

Put a stock dist. back in and see if the knock is still there, although if the timing is advanced to far the sound is more like a rattle than a thud,thud knock .

Yup, if it clatters I'd bet you're timing is too advanced.

[Tom Wesenberg]

Originally Posted by Ian in Mississauga

Please let us know what you find. I've got the identical problem only with stock ignition. I've been working on a spare just in case.

My engine had a bad engine knock problem, even with not much advance. It was due to an accumulation of rust flakes in the rear of the block cooling chamber, which caused a hot spot. Once I used the vinegar treatment to get rid of the rust, the pinging went away.

[James Rogers]

Really sounds like a high compression head with too much advance. You could try a tank of high octane gas or some octane booster just to see if it helps. Ultimately, the timing is going to need work. You will probably need to recalibrate the mechanical advance in the distributor to get it fixed. How was the distributor used before you got it? Was it used for racing? This could explain much.

[Reddy]

I did just install super winfield head and cam, at the same time I did the distributor.
So maybe the gas is to low in octane. Thank you all, I be working on this today and hope the timing and gas will help.
Mike