Author Topic: Noisy distributor  (Read 2113 times)

hotrod68

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Noisy distributor
« on: July 04, 2013, 05:47:26 AM »
   Has anyone ever heard of an oil pump driveshaft being too short? The tabs are only engaging the distributor shaft by about 3/16". The distributor is a new Pertronix that has run perfectly in another engine and matches the length of a stock distributor exactly. I've shimmed the gear and taken out any excess slack so it couldn't climb up under resistance from the oil pump. The oil pump shaft is a new ARP that matches a stock shaft in length. The engine is a 383 stroker with a Comp Cams small base-circle roller. The manifold is a Team G that--as with the distributor--worked perfectly on another engine. The heads are AFR 210s from the same engine. Nothing is different except for the short block. The valves are lashed correctly.
    When running the engine has a loud clacking sound that sounds like a loose rocker arm, and I believe it's coming from the oil pump driveshaft jumping around because it isn't fully seated in the distributor shaft. Oil pressure is fine. I've never encountered this before and would appreciate any advice or feedback. Thanks.
HotRod'68  1968 SS350 coupe undergoing frame-off resto/rod. 386/350/4.11s
Butternut Yellow    black standard interior

WorkinProgress

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Re: Noisy distributor
« Reply #1 on: July 04, 2013, 11:24:43 AM »
Not sure if this is the problem, but do you have the nylon connector installed that goes between the oil pump shaft and distributor?

                                                                                                              - Warren

JohnZ

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Re: Noisy distributor
« Reply #2 on: July 04, 2013, 02:44:41 PM »
Chevy II oil pump? They used a different pump shaft.
'69 Z/28
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hotrod68

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Re: Noisy distributor
« Reply #3 on: July 04, 2013, 10:36:17 PM »
The ARP shaft has a steel collar instead of plastic where it meets the oil pump, so that can't be it. The oil pump is a new Melling hi-perf unit designed for a regular rear-sump pan, so that can be discounted as well. This thing really has me stumped because it makes absolutely no sense. Thanks, guys.

janobyte

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Re: Noisy distributor
« Reply #4 on: July 04, 2013, 11:58:03 PM »
With that roller cam , did you upgrade the gear on the distributor, brass?   one drift pin to make the change---easy

janobyte

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Re: Noisy distributor
« Reply #5 on: July 05, 2013, 12:04:41 AM »
BTY I've been running melling pumps with ARP shafts for over 20 years with no issues. Did you tack the pickup to the pump ? another thought .

hotrod68

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Re: Noisy distributor
« Reply #6 on: July 05, 2013, 05:45:00 AM »
  The cam has an iron distributor gear and I'm using a regular iron gear on the distributor--no bronze gear required. And the oil pump has the bolt-on pickup instead of being pressed in. This is what doesn't make sense--everything in the engine is hi-quality and high-dollar. It's really weird. Thanks.

ss jim

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Re: Noisy distributor
« Reply #7 on: July 07, 2013, 01:09:05 AM »
Did you use a cam button or any other method to limit the can from "walking" in the block?
Jim

hotrod68

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Re: Noisy distributor
« Reply #8 on: July 07, 2013, 04:09:49 AM »
Yep. I used a Comp timing set with the Torrington bearing behind the cam gear, and a Comp thrust bearing on the front set at .005" endplay.
I'm positive that the cam isn't walking.

janobyte

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Re: Noisy distributor
« Reply #9 on: July 10, 2013, 07:34:19 PM »
Figure out the source of your noise ?

hotrod68

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Re: Noisy distributor
« Reply #10 on: July 14, 2013, 07:06:00 AM »
jano............I did.  And it's embarrassing. When I was lashing the valves before I buttoned up the engine, my brother showed up and I got distracted. I put the RS valve cover on and never lashed #8 cylinder. When in doubt, go back to the basics. I started checking the valves and on #8 the pushrods must have had 1/4" clearance. I hadn't even run the polylocks down. It explained the skip, the rattle, and that I'm getting old......lol. Now the 386 purrs like a kitten. I hope this can be a lesson to any who read this post. The best of us can make mistakes. When in doubt........go back to the basics.

janobyte

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Re: Noisy distributor
« Reply #11 on: July 14, 2013, 11:52:21 AM »
Great feeling when you find nothing more than a minor oversight , no $$$ !

69Z28

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Re: Noisy distributor
« Reply #12 on: July 14, 2013, 05:37:45 PM »
I go thru my check twice just so I know I didn't forget one adjustment. Check once and rotate engine a few revolutions with out the spark plugs in, check once more to back up your first adjustment. Always works for me. I don't even have a radio on when I do them, no noise, no distractions, and if I get distracted, I start over.
GaryC

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janobyte

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Re: Noisy distributor
« Reply #13 on: July 14, 2013, 11:29:21 PM »
MAC tools makes a set of "quick sticks" : TDC ,adjustments per cylinder are laid out ( lays in the head , a notch is provided for each push rod ) turn over 180 deg., finish. I/E plus cylinder are marked . Mine are very old, 20 + years. Stole from Dad, he knows where they are . Like I said ,oversights happen ( #$%@) If you walk away without a hit to your wallet, no big deal.