??Distributor shaft depth in oil pump drive??

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MICHAEL J KLOCK

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Ok, I have an unusual question. I'm planning on using a Petronix distributor in my new small block. The oil pump drive shaft bushing is new (MOPAR), the oil pump shaft is brand new (MOPAR). When I install the Petronix distributor it only sits inside the oil pump shaft coupling @.090"
That's not a lot!! So I pulled my MOPAR Performance distributor out of my running 360LA and installed it, and it appears it's depth is the same. I took measurements with the dist shaft sitting crisscrossed on the shaft and measured dist base housing to the engine block. (.090") I also used machinist dye on the bottom of the distributor shafts to get a visual wear pattern. Am I crazy or should this sit deeper inside the oil pump drive shaft. The picture of the dist shaft that looks deeper is the mopar performance unit. It looks deeper because the ends of the shafts are cut differently. The MOPAR and Petronix shaft lengths are the same.

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With the engine running the oil pump gear tries to move up and will close that gap.
 
You don't want it moving because it will change your timing. It's turning the oil pump that is hard to turn when making pressure and it's pulling the shaft down not pushing it up. do you have a gasket on the dizzy or does it have a o-ring
 
It's only turning the dizzy so there is no pressure on the dizzy shaft.
 
brian6pac said:
You don't want it moving because it will change your timing. It's turning the oil pump that is hard to turn when making pressure and it's pulling the shaft down not pushing it up. do you have a gasket on the dizzy or does it have a o-ring
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It’s O ringed
 
Don't know if it's normal but it is probably plenty to turn a distributor
 
The bushing can be shimmed before it is installed and usually will be checked by the builder if gear alignment is off. That will lift the gear. That said after installing many distributors. Not many drop down more than that on a original motor due to bushing surface wear from the cam pushing down

. If its a new build correct the problem while it's apart. Make sure you hone the bushing to size for oil clearance. If it is to tight it may spin in the block when it initially gets hot for the first time.
 
Interesting will start to measure a few cores and see where they sat by the wear pattern.
 
I spoke to one of the members that lives near me this morning, he measured an old cooler and told me it was about .150”
In all my years of working on cars I never once had to measure a distributor shaft depth, not too common of a problem to have
 
The oily distributor bushing is in my running 360, the dry one is in my stroker with the problem. I'm thinking......does it look "crushed"
Maybe he wailed it in the block and deformed it?

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I don’t know, but the face of the bushing doesn’t look right. It actually looks lower that the block itself. Look at the photo and you can see it’s ever so slightly higher than the block.
 
I’m going to remove the bushing. I ordered the OTC puller and the correct installation tool. Unfortunately I’ll have to remove my oil pan and pump to fit the shaft properly. I don’t want and metal falling in the engine.
 
I would get a piece of half inch steel and see if it hangs up at all, might just look that way.
 
MICHAEL J KLOCK said:
I don’t know, but the face of the bushing doesn’t look right. It actually looks lower that the block itself. Look at the photo and you can see it’s ever so slightly higher than the block.
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See it now. Wonder if the FSM has specs on how high? I would think it would be bottomed out in there.
 
halifaxhops said:
See it now. Wonder if the FSM has specs on how high? I would think it would be bottomed out in there.
Click to expand...
I wonder if the installer just smashed the face of the bushing? Installed it with a sledge hammer!?!?!
 
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No idea. I have always had them installed by the machine shop, why buy a tool I will use maybe twice?
 
Have you measured the actual distance from the top of the block where the distributor sits down to the intermediate shaft itself?
I see the contact area on the distributor shaft, but I'm wondering if it sits further into the slot than the contact mark itself is suggesting.
Incidentally, one of the large engine mount bolts from a Magnum equipped fullsize Ram is the perfect size to use as a puller for that bushing. It threads in tight enough and has a flanged head, so you just use two pry bars to evenly pull the bushing right out.
 
I know I am late but I had to check it out.
I do not think .090 is good.
The tip is approx. 1/4 " I have a pair of used distributor shafts and the wear pattern is one half of the tip. More like .170 to .190 Nice deburring of your block and looks to be clean. Also I like that you take blue printing of a motor to heart.
If you want photos I will do that for you. I would try a different oil pump drive first.
 
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