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Rod...from a Chrysler?
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Discussion Starter · #1 ·
I just changed the cam on my 350 TPI. I dropped the dizzy in and there's about 1/32'' gap between the base and the intake.

Anyone have this issue before?
Block and heads have not been machined BTW.

Could the tang on the dizzy be sitting on top of the oil pump drive rod?
 

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Administrator
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Have you tried tapping it down a bit?...I have seen where its a tight fit and needs a little persuasion. Check to see if there might be something down there (gasket material etc)
 

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Did you make sure the gasket is still on the distributor? Once you do get it down, verify that the you still have some slight endplay with the shaft to make sure you are not forcing the oil pump shaft into the oil pump body.
 

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WFO
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5,030 Posts
After you verify the distributor is correctly aligned w/the oil pump drive shaft, check that the distributor isn't bottoming out. If it is, it can be adjusted using nylon shims.

BTW, if the distributor wasn't lining up w/the drive shaft it should be a lot more than 1/32" above the intake flange.
 

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Rod...from a Chrysler?
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Discussion Starter · #5 ·
Thanks guys.

Nice link for the dizzy wiki Cobalt.

Looks like I may need some of those nylon spacers. Since I didn't do anything with the block, heads or intake, I was most likely driving it around with the oil pump drive shaft tight against the distributor tang all this time.


This engine was not originally a TPI motor. I wonder if a different pump/drive shaft was used than what I'm running now. Maybe the L98 heads kept the intake higher?

Do you think I grind a bit off the bottom of the dizzy tang?
 

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WFO
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Thanks guys.

Nice link for the dizzy wiki Cobalt.

Looks like I may need some of those nylon spacers. Since I didn't do anything with the block, heads or intake, I was most likely driving it around with the oil pump drive shaft tight against the distributor tang all this time.


This engine was not originally a TPI motor. I wonder if a different pump/drive shaft was used than what I'm running now. Maybe the L98 heads kept the intake higher?

Do you think I grind a bit off the bottom of the dizzy tang?
That will work as long as the drive shaft isn't what's grounding out up inside the distributor gear, if you follow. It could be the male dist. shaft bottom hitting the bottom of the groove of the female pump drive, OR the sides of the female drive could be hitting up inside the distributor gear. I don't have a pump drive handy (do have a dist. right here;)) or I'd check to see which it would be for sure.

Hopefully driving like that hasn't damaged the oil pump. You can inspect the thrust washers/spacers on the distributor (between the gear and housing) for wear or damage/signs of overheating.
 

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Rod...from a Chrysler?
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Discussion Starter · #9 ·
With a long screwdriver I align the pump tang like this.



Then set the rotor so it turns to number one as the dist. is lowered into the block.
Thanks Malc but this is not the issue.

I was having a problem lining up the screwdriver to the slot so I took the gear off an old distributor to use as a tool to align the pump drive to exactly where I want it. I then pulled that and dropped my good dizzy in. Its going down all the way except about .030". I have at least .060" interference as I would assume about .030" required end play between the pump drive and distributor tang.

Its definately dropping in with a thud, metal to metal contact.

Thanks,
Pugsy
 

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Rod...from a Chrysler?
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Discussion Starter · #11 ·
I just changed the cam on my 350 TPI. I dropped the dizzy in and there's about 1/32'' gap between the base and the intake.QUOTE]

Er.....you do have a gasket in there don´t you ?
Sorry, forgot to mention that I had a gasket there.
Smaller gap with 2 gaskets of coarse.
 

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JS-70
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I always measure mine without the gasket, and make sure the distrbuter sits flush and not in a bind. Then add the gasket, you know you wont be too tight. If necessary you can get the proper shims to shim that up 1/16th or so. then add your gasket. This way you know the oil pump wont be in a bind. Do it the right way first, dont be grinding on stuff to make it fit.
 

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Rod...from a Chrysler?
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Discussion Starter · #13 ·
And the verdict is in.

After fiddling around with it, the stars and planets all lined up and she dropped down all the way without a gasket. :thumbup:

I know its not binding as I can lift the distributor end play by pulling up the rotor. Its not being forced up.
 

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WFO
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And the verdict is in.

After fiddling around with it, the stars and planets all lined up and she dropped down all the way without a gasket. :thumbup:

I know its not binding as I can lift the distributor end play by pulling up the rotor. Its not being forced up.
I'm sure you're probably fine, but were you able to tell that there is more than just 1/32" engagement between the distributor shaft and the oil pump drive shaft? Like at some point did the distributor sit way proud of the intake (like over 1/4" or so) when the alignment between the two shafts was off?

Just checking, 1/32" is not enough engagement as I'm guessing you know.
 

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Rod...from a Chrysler?
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Discussion Starter · #16 ·
I'm sure you're probably fine, but were you able to tell that there is more than just 1/32" engagement between the distributor shaft and the oil pump drive shaft? Like at some point did the distributor sit way proud of the intake (like over 1/4" or so) when the alignment between the two shafts was off?

Just checking, 1/32" is not enough engagement as I'm guessing you know.
No, it was just sitting up a wee bit.

I found my old gasket on the floor and found it was indeed squished nicely from when I took it out.

I'm sure its fine.
 

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WFO
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I don't think I explained myself well enough. What I'm saying is, is when the distributor is put in "wrong" and the pump shaft is not aligned correctly w/the distributor shaft, the distributor- in that position- should sit a lot higher off the intake than just 1/32".

It should be at least 1/4" or more off the intake. If all there is is 1/32" engagement between the distributor shaft and the oil pump drive shaft when they're correctly aligned to each other, that is not enough.:)
 

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Rod...from a Chrysler?
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6,081 Posts
Discussion Starter · #18 ·
Keep in mind that the problem was not that the dizzy tang was on top of the pump drive and had 1/32" gap. It was after engagement of the tang and pump drive that it was riding high.

Of coarse its about 1/4" up if I miss the alignment with the pump shaft.

After some wiggling and stuff it dropped right down onto the intake even w/o the gasket.

Maybe the pump rod was not exactly straight or?? when I was dropping it in?

I do know I am engaging the pump rod as I pulled the dizzy up and turned the pump rod 360* by advancing one tooth of the dizzy gear and dropping it back down each time.

I had forgot about this simple pump rod trick until I was fiddling with it. I didn't need a screwdriver or spare dizzy to line it up. DOH!
 
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