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Discussion Starter #1
ok long story short. I went to lock my timing, and found a almost worn out bronze distributor gear. The problem is, when speedomotive set the distributor the failed to check where the gear is riding on (bottom .250 of the bronze gear). I pulled the oil pump to check the shaft length, and it is a long tall deck shaft. Distributor is bottoming out on the shaft.
Any help? thanks. Oh yeah...tall deck 572 dart block with an msd dist and a high vol oil pump
 

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The biggest variable is usually the intake manifold, and how it fits on the heads and block. The oil pump and oil pump drive shaft will be the same for standard or tall deck. The pump drive engagement into the distributor gear should really be measured and checked with any new build. A quick and dirty method is to drop the distributor with no gasket and see how much space between the distributor and manifold.
 

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Discussion Starter #3
I had a long shaft in it, the standard shaft is .500 shorter. The msd I have has a slip collar, so I don't think the intake mani has anything to do with it. The problem is that the shaft bottoms out on the distributer before the gear centers on the cam
 

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Like Barry said the oil pump shaft is normally standard length. That's why they make long distributors (or slip collars) for tall decks. I'd try a std length shaft and adjust accordingly on the dist with the slip collar. (If it's a tall deck distributor). It's obvious from your description that your shaft is too long holding the distributor up.
 

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Damaged pump?

There is a really good chance the oil pump is toast. If you've been running it with the distributor bottomed on the shaft the drive impeller has eaten the cover and all those metal pieces went through the pump. Hopefully the filter caught the majority of the metal. I would surely check the pump for damage, and the half moon shinny mark aint suppose to be there........MP

PS I have seen many engines messed up because no one checked the distributor without a gasket, and/or failed to space it between the intake......
 

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Excellent point by MP. I didn't realize you'd actually run the engine.... (Rexone needs to read slower) ;)

Definitely check the oil pump, and possibly the whole engine if metal is present.
 

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Discussion Starter #7
I pulled everything apart and no damage. I also put in the standard lenght shaft and it works good, but has play between the pump and distributor, I wood say the distributor is only catching about .200 of the shaft. Shout I just machine the long shaft to make it fit a little better?
 

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Discussion Starter #9
NO, drop the distributor in the hole without a gasket, all the way down, lock the collar, remove and reinstall with a gasket. Where the hell did you get a 1/2 longer shaft?
just so people don't think I don't know what i'm doing, ARP has to part nubers for the shaft a tall deck and a standard. The machine shop put in the longer of the two. I understand how to drop it in and set the collar with no gasket, if you take a look at my post I said with the longer shaft the dist won't go below the bottom of the dist gear (in other words its riding on the bottom .250 of the gear
 

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slow down and measure

The distributor needs to be at the right depth so that the oiling groove connects the lifter galleys and material above and below the groove needs to seal that groove off so you dont have a HUGE internal oil leak. the gear height will be correct if you take care of this. the only longer chevy shafts were for use with oil pump spacers.

pat
 

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Discussion Starter #13
I believe the raised cam blocks also require a longer shaft and that is what ARP sells the longer shaft for http://store.summitracing.com/partdetail.asp?part=ARP-135-7902&autoview=sku he needs to get the right shaft. Somebody order this thinking that tall decks need a longer shaft.:)sphss
ok thank you. so one more time to clear things up...what I did (order the right standard length shaft) was the proper way. What speedomotive out in west covina did (put the wrong LONG shaft in it and failed to check gear location) was the wrong thing to do. So if I wouldnt of pulled that dist out just out of being bored I would of damaged a little more than a gear.
 

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Discussion Starter #14
forgot to mention, the advise of cutting down the longer shaft instead of using the standard one came from speedomotive, they are a machine shop that are supposed to be real good
 

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Interestingly enough, not only do Summit and Jegs show ARP 135-7902 to fit "tall deck Dart and Merlin blocks", but so does the current ARP Catalog online. None say anything about "raised cam". I suppose anyone selling ARP who simply copies their information will have the exact same description.
 

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Discussion Starter #16
ok misunderstanding about speedomotive. my brother talked with george last week and cleared things up about the long shaft. Nothing bad to say about there machine work, the motor they built runs great so far no trouble, besides the distributor deal.
 

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The 1/2" long shaft oil pump drive has been around for a while. There may be other uses, but I'm pretty sure it was originally to use a BBC oil pump in a SBC block. Was a "speed secret" for guys racing a SBC. When we raced cars, I ran a SBC and pretty sure I had that set up in our back up engine years ago...
 
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