Oil pump drive ???

[Newbomb Turk]

That's funny, My son and I are going through the same thing on one of his costumers cars. It's a 351 Cleveland, two Holley Sniper distributors, one drops all the way in no problem. The other doesn't even make it to the o-ring seal before it locks up. Every thing measures the same on both of them, one fits the other doesn't. Guess we are going to be checking the run out on that next, just so we know. Thanks for the heads up Newbomb Turk.

Wow! That is interesting. Like I said I’ve never seen this before. I’ve never even heard of it. Thanks for letting us know it’s not just a Chrysler thing.

 

[Max1196]

It's a 351 Cleveland,

Newbomb, I'm momentarily going to but-in here, Can you check the "hex" size on the end of the distributor, Is it a .250 diameter or a .312 diameter? Now back to the bent Dodge stuff..

 

[Newbomb Turk]

Newbomb, I'm momentarily going to but-in here, Can you check the "hex" size on the end of the distributor, Is it a .250 diameter or a .312 diameter? Now back to the bent Dodge stuff..

I measured it yesterday and it was .310 and a couple of tenths across the flats.

I measured across the points but I forgot what that was. I’m going out there in a few minutes to put the pan back on so I’ll measure that again and report back.

 

[Vertex_Jeff]

Maybe when the gear was pinned on, it got bent? Someone using a press with a haphazard support/ tooling jig or whacking the pin with a hammer.......

 

[NC Engine Builder]

I just ran into the same thing on a gen 1 392 I'm building. But on those, they sell you a shaft and gear separately that you have to press the gear on and then pin it. It's a retrofit deal to put a LA pump on the early hemi cap. Anyway, the hole in the block was only a few thousandths bigger than the shaft, so it was rubbing. I had to straighten it as well. What are the odds

 

[Newbomb Turk]

Maybe when the gear was pinned on, it got bent? Someone using a press with a haphazard support/ tooling jig or whacking the pin with a hammer.......

It’s possible they bent the shaft when the gear was pressed on.

Once I got it straight I put the dial indicator on the base of the gear and the runout was the same as the shaft so I assume the gear is on straight.

Of course now that I typed that out I need to pull the drive back out, get it back in the lathe and indicate the face of the gear.

Why my dumb *** didn’t do that first baffles me.

 

[gzig5]

It’s possible they bent the shaft when the gear was pressed on.

Once I got it straight I put the dial indicator on the base of the gear and the runout was the same as the shaft so I assume the gear is on straight.

Of course now that I typed that out I need to pull the drive back out, get it back in the lathe and indicate the face of the gear.

Why my dumb *** didn’t do that first baffles me.

I'll guarantee you that a 1/2" shaft isn't going to stay straight through a heat treat and quench cycle. I would think they have to do a little straightening after heat treat. If it wasn't properly tempered, the steel could have had some stress in it that caused it to move. When you are working in fine tolerances, people would be very surprised at how much steel will move over time or due to temp fluctuation if there is any unrelieved stress in it.

 

[Newbomb Turk]

I'll guarantee you that a 1/2" shaft isn't going to stay straight through a heat treat and quench cycle. I would think they have to do a little straightening after heat treat. If it wasn't properly tempered, the steel could have had some stress in it that caused it to move. When you are working in fine tolerances, people would be very surprised at how much steel will move over time or due to temp fluctuation if there is any unrelieved stress in it.

Yup.

So pulled the drive back out and checked the face of the gear.

It was less than .0005 TIR. So it is on the shaft square.

To save myself all the extra work I will never just drop in a drive like that again. They will all get checked.

If this was a customer’s engine I would have just burned any profit I thought I would make unscrewing that.

If I could have removed the drive through the distributor home it would have been easy.

Somehow it wedged itself so hard into the cam gear it would not come out.

Taking my pan off and on is a real beeotch too.