??Distributor shaft depth in oil pump drive??

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I asked this question years ago to an old retired Chrysler mechanic and he said the design was intentional in case the oil pump locked up it would twist the end ot the distributor shaft and cause the engine to stop running and essentially protect itself from further damage running with no oil pressure. Looking at it in that light, I would want "just enough" distributor tang in the slot to drive the distributor. .090"-.150" seems sufficient. "It doesn't take much" to turn it at all.
 
This is the “burnishing tip”

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MICHAEL J KLOCK said:
Photo attached....

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The Pioneer bushings do not need burnishing. They are machined so that when they are installed, they are the correct diameter. The intermediate shaft will slip right into them. I have installed a LOT of them. The only bushings I have ever seen that required the burnishing tool were the Mopar bushings. If you burnished the Pioneer bushing, it is probably too big.
 
RustyRatRod said:
I asked this question years ago to an old retired Chrysler mechanic and he said the design was intentional in case the oil pump locked up it would twist the end ot the distributor shaft and cause the engine to stop running and essentially protect itself from further damage running with no oil pressure. Looking at it in that light, I would want "just enough" distributor tang in the slot to drive the distributor. .090"-.150" seems sufficient. "It doesn't take much" to turn it at all.
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maybe i'm not understanding this right , but I don't understand how the dist shaft would twist off if the pump seized .
 
jimjimjimmy said:
maybe i'm not understanding this right , but I don't understand how the dist shaft would twist off if the pump seized .
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The was it was explained to me was, if the pump seized all at once, the rest of the engine would want to keep turning through inertia. Hay I have no major in physics, but it sounds good. lol
 
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Rusty, I agree with you that the Pioneer bushing does not require burnishing. But, the burnishing tool gets pulled through the bushing one time, and the end is a fixed size
.485”.
When it’s pulled through the MOPAR bushing the hole ID will be .485”
When it’s pulled through the Pioneer bushing it will be .485”. It can’t be bigger than that.
So I disagree that the hole is too big.
I will however remove the burnished one and replace it without burnishing since they came in a pack of 10.
 
MICHAEL J KLOCK said:
Rusty, I agree with you that the Pioneer bushing does not require burnishing. But, the burnishing tool gets pulled through the bushing one time, and the end is a fixed size
.485”.
When it’s pulled through the MOPAR bushing the hole ID will be .485”
When it’s pulled through the Pioneer bushing it will be .485”. It can’t be bigger than that.
So I disagree that the hole is too big.
I will however remove the burnished one and replace it without burnishing since they came in a pack of 10.
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I realized that after I posted it but I am just too damned lazy to change it. lol
 
RustyRatRod said:
I asked this question years ago to an old retired Chrysler mechanic and he said the design was intentional in case the oil pump locked up it would twist the end ot the distributor shaft and cause the engine to stop running and essentially protect itself from further damage running with no oil pressure. Looking at it in that light, I would want "just enough" distributor tang in the slot to drive the distributor. .090"-.150" seems sufficient. "It doesn't take much" to turn it at all.
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If the oil pump seized then the oil pump shaft would not turn. If the oil pump shaft did not turn, then the distributor shaft would not turn. The cam gear drives the oil pump shaft and gear, which is coupled to the distributor. I don’t see how the tip of the distributor would break off. Lol.. just my 2 cents..
 
MICHAEL J KLOCK said:
If the oil pump seized then the oil pump shaft would not turn. If the oil pump shaft did not turn, then the distributor shaft would not turn. The cam gear drives the oil pump shaft and gear, which is coupled to the distributor. I don’t see how the tip of the distributor would break off. Lol.. just my 2 cents..
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Oh I know how it's designed, but whose to say what might happen with the engine running at highway speed for instance?
 
I can tell you this. The small and big block Chevy engines WERE designed to break away in case of oil pump failure. They all came from the factory (except the very HP models) with a plastic bushing that held the oil pump drive to the oil pump. It was meant to fail first.
 
MICHAEL J KLOCK said:
Agreed
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I'll tell you another engine that should have had that design. Every single Ford V8 with a front drive distributor. I've seen more than a few of those ring the oil pump drive shaft right off and keep on truckin until they came apart. On those, the driven gear is on the distributor, similar to the Chevy, so they'll just keep right on until they don't. LMAO The Fords were ESPECIALLY bad about the valve stem seals cracking up, falling into the pan and getting sucked into the oil pump, then kablewooy. Seen that a lot over the years, too. A lot more than any other make.

But getting back to this Chrysler thing, there was on guy on here recently who had this happen. "Somehow" the distributor/intermediate shaft/something pushed the distributor out of the hole on the block and twisted the tip of the blade. After that, he couldn't get it back running again. There's a lot more, but I'll just stop "right there". If you find the thread you'll see what I mean. Lots of stuff that make you do this......:BangHead:
 
I lost a rebuilt 302 at start up due to twisting off the oil pump driveshaft, had been stored for a while and somehow a dirt dobber got a nest inside and the grit locked up the oil pump, 2 new pistons and oil pump shaft later and it ran good. Roller cam.
 
I'm wondering…..
How many people put carb gaskets on dry, or spray with WD-40, or use Gasgacinch?
 
Another question,
Does anyone know why MOPAR stopped producing the Six Pack manifold? Seems their unavailable new.
 
I'm a few days late to the party here but had a very similar issue with the distributor. Converted from the Mopar Performance to Mallory that comes with the Pro Flo 4 system. The MP distributor engaged about .100 but the intermediate gear has a slight chamfer. The MP shaft did not have a chamfer but the Mallory did. End up the two chamfered sections were all that was contacting and allowed about 15 degrees of free rotation. All measurements pointed to the distributor and edelbrock swapped it out for me. A new intermediate gera and bushing combined with the new distributor (.040) longer fixed the problem. I picked up the Proform tool from summit and worked well for about $100. Top distributor is the Mallory, bottom is MP.
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