New engine knock! Oh Lordy!

[ivoryjohn]

Today I cranked up my new engine for the first time in the car but not after dealing with a vexing lack of spark to the points. After I nervously did the few things I knew to do to check it out I called two friends whining and complaining.

Thank the Good Lord for patient and understanding friends in the hobby. It was because of them I checked the ignition cable to see if it was screwed in too far and shorting out the distributor. I have bitten by this mistake and was sure this wasn't the problem because I had only screwed it in a turn and a half. It was not enough turns to make contact as it happened and I fixed it.

I am a pretty laid back fellow and don't get alarmed over the day to day problems in life. Nor did I get upset in rough seas in my profession as a boat captain. When my child was playing with the chainsaw or climbing high enough the fall would likely kill her, rather than stop her or panic I would only yell out the warning, "Don't get any blood on anything!" But today when I started up my new engine for the first time and there was a fast solid loud knock like someone hitting the engine with a monkey wrench I panicked like the barnyard animals in the "Chicken Little" story..."Oh Lordy The Sky IS Falling!" Time to call a friend Regis!

I tore up the telephone wires dragging one friend away from lunch with the Preacher and the other from what may have been a sure thing customer on the sales floor. "Oh me The Sky is Falling...my four thousand dollar engine with the high compression head is making a terrible racket!", I blubbered.

Okay maybe I am exaggerating a little but I have had two wives leave me with less emotion than what I experienced hearing this engine clatter like it did. I was scared to run it to see if it got any better. It had plenty of time when I ran it before to get up oil pressure, how is running it now going to help?

I called my buddy 60 miles away to arrange a fix and time to trailer it north. I hate Model A's on trailers and won't own one of my own. I have to borrow one. "But before you come check and see if anything is hitting anything on the front pulley." He says.

There was just a trace of evidence that the spokes of the new one piece crank pulley was hitting the front motor mount yoke. This little touch was making all that noise? Cautiously I cranked it up and cried at the sound but I sped it up and slowly it got better. By the time I got to the street down my driveway you could hardly hear it. I called my friend and told him not to expect me I wore it in. The sky wasn't falling after all. It was just a little rain.

[Pilotdave]

Whew! Glad it worked out as it did.

[700rpm]

If it was sitting for a long time, did you pour oil down the distributor hole and into all the cylinders through the spark plug holes before you fired it up for the first time? If it's still making a noise, take the plugs out and turn it by hand and see if you can determine where the noise is. There's something wrong with the pulley installation if it's hitting the motor mount; that has to be addressed.

Is it running OK now?

[ivoryjohn]

Originally Posted by 700rpm

If it was sitting for a long time, did you pour oil down the distributor hole and into all the cylinders through the spark plug holes before you fired it up for the first time? If it's still making a noise, take the plugs out and turn it by hand and see if you can determine where the noise is. There's something wrong with the pulley installation if it's hitting the motor mount; that has to be addressed.

Is it running OK now?

I brought the new engine home just after hearing it run on a test stand last Sunday. The engine was hitting on the pulley spokes and I agree that the engine pulley and motor mount shouldn't hit. I am thinking it is a repro fault of either the motor mount or the pulley. My old engine had a two piece pulley and there was no problem with it but I understand two piece units are undesirable.

After the engine ran for a few minutes and giving me heartburn, the noise went away and there is no damage to the pulley that I can see. The new engine runs great and I'll be nursing it for the next 500 miles during break-in.

I have to laugh at myself for how wrapped up in this pile of old iron I actually am. Really I am a pretty laid back guy but let something not be right or go wrong with my baby and I act like an fussy old woman and fall to pieces.

[700rpm]

Inspect that pulley very carefully for cracks or damage. You don't want one of those to blow up.

[Richard Wilson]

Sponsored Links (Register now to hide all advertisements)

On a newly purchased Model A project the single piece crank pulley had rubbed on the front engine mount because of a stripped mounting bolt hole. There was a 1/32 inch grove worn into the pulley that was barely visable. I fixed the striped bolt hole and thought all was fine until almost a year later the pulley broke right on the groove cut by the yoke.

[ivoryjohn]

Originally Posted by Richard Wilson

On a newly purchased Model A project the single piece crank pulley had rubbed on the front engine mount because of a stripped mounting bolt hole. There was a 1/32 inch grove worn into the pulley that was barely visable. I fixed the striped bolt hole and thought all was fine until almost a year later the pulley broke right on the groove cut by the yoke.

Thanks for the post and warning. My engine will be going back to the builder in the car this weekend for repairs if needed and replacement of the crank pulley. I will direct him to your posting.

The sound was substantial enough that I have to think the metal hitting metal was hard enough to do damage. He initially wanted to somehow get a grinder in there to grind on the engine mount to make room for the crank spokes. I would rather fix the correct cause not the resulting problem. If you fix the cause the problem goes away.

I did take note from another post that there are different size crank pulleys. I wonder if they are all Model A? And how does that affect the clearance between the crank pulley and motor mount. I will measure the diameter of mine this morning.

[1931 flamingo]

The previous postings about crank pulleys, were the diff figures about depth and NOT diameter?? Correct me if I'm wrong, please.
Paul in CT