73 Distributor whine / squeal
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 22
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73 Distributor whine / squeal
I recently swapped out intakes from a Torker II to a Performer RPM. Afterwards everything came back together the way it should have and I can get the car to idle, BUT I'm getting this horrible whine from the distributor.
So far I've tried loosening the hold down and jiggling the distributor in place, shimming the distributor, applying die electric grease to the rotor and nothing seems to get rid if it. It has been converted from points to an MSD box.
It's RPM dependent and sometimes when it gets bad (changes tone) the car wants to die.
I pulled the shaft and did not see any unusual wear.
The only thing that has changed is the intake. The only hypothesis I have is that the intake is warped, but before I pull it and try running the car with the other intake, I was hoping one of you might be able to identify this.
Here is a video of the issue
So far I've tried loosening the hold down and jiggling the distributor in place, shimming the distributor, applying die electric grease to the rotor and nothing seems to get rid if it. It has been converted from points to an MSD box.
It's RPM dependent and sometimes when it gets bad (changes tone) the car wants to die.
I pulled the shaft and did not see any unusual wear.
The only thing that has changed is the intake. The only hypothesis I have is that the intake is warped, but before I pull it and try running the car with the other intake, I was hoping one of you might be able to identify this.
Here is a video of the issue
Last edited by geodiego; May 25, 2015 at 07:10 PM.
6th Gear
Joined: May 2015
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Hard to tell from the video but I'd be more inclined to think it's a vacuum leak as it seems to act up more as the throttle is released back to idle and vacuum is at it's max. You might try using an unlit propane torch to direct gas around the carb base and manifold gaskets to see if idle picks up indicating a vacuum leak. Be very careful and have a fire extinguisher nearby just in case.
Thread Starter
Heel & Toe
Joined: Apr 2009
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I'll try the flame close to the carb, but pretty sure that's not it, it has a new gasket and I took a straight edge to the mating surface for just that reason.
Thread Starter
Heel & Toe
Joined: Apr 2009
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Yeah - I agree, horrible sound, but most definitely coming from the distributor housing. Pretty sure it's a mechanical in nature, but don't know what in the distributor could be causing it.
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
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Dry or worn out bushings.
You might want to take the distributor apart and have a look at the bushings.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
Take a 4 foot piece of large hose (like 5/8" garden hose) and hold one end to your ear (while plugging the other ear) while probing around with the other end. You'll quickly find its something like a bent alternator fan or front bearing seizing or the power steering pump is completely dry. There is nothing in a distributor that can cause a LOUD squealing at that high of speed. I'm betting on the noise coming from your alternator....................
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Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 22
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Thanks for the suggestions. I checked the cap and rotor and didn't see and wear or material under the cap. I also put a dab of die electric grease on the rotor to see if the sound went away for a sec and no change. Under the rotor I did an inspection of the springs/weight but without RPMs it's hard to see what might be wrong besides anything weird happening while I push/pull them. I think I'm leaning towards bushing issues right now. It is the original (converted) distributor after all :-) I ordered an HEI/tach drive distributor from dragonfire. I'd planned this upgrade anyhow, hopefully this takes care of my issue.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,170
From: Hermosa
I had a similar issue with an HEI unit. Mine made that same noise although less intense and it was due to cam walk. The cam was forcing the shaft of the rotor drive into the housing bushing.
I disassembled the unit and it was pretty obvious what was happening. I think if you took yours a part you would see the wear to the busing(s).
Could be that the new intake has the hole in a slightly different position or angle and it's causing a slight binding of the rotor shaft causing it to be pushed into the housing bushing? How is the end play on the distributer? Is the gasket in place? Could be it's being forced down into the gear on the cam if the spacing is wrong causing binding.
I disassembled the unit and it was pretty obvious what was happening. I think if you took yours a part you would see the wear to the busing(s).
Could be that the new intake has the hole in a slightly different position or angle and it's causing a slight binding of the rotor shaft causing it to be pushed into the housing bushing? How is the end play on the distributer? Is the gasket in place? Could be it's being forced down into the gear on the cam if the spacing is wrong causing binding.
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 22
Likes: 0
I had a similar issue with an HEI unit. Mine made that same noise although less intense and it was due to cam walk. The cam was forcing the shaft of the rotor drive into the housing bushing.
I disassembled the unit and it was pretty obvious what was happening. I think if you took yours a part you would see the wear to the busing(s).
Could be that the new intake has the hole in a slightly different position or angle and it's causing a slight binding of the rotor shaft causing it to be pushed into the housing bushing? How is the end play on the distributer? Is the gasket in place? Could be it's being forced down into the gear on the cam if the spacing is wrong causing binding.
I disassembled the unit and it was pretty obvious what was happening. I think if you took yours a part you would see the wear to the busing(s).
Could be that the new intake has the hole in a slightly different position or angle and it's causing a slight binding of the rotor shaft causing it to be pushed into the housing bushing? How is the end play on the distributer? Is the gasket in place? Could be it's being forced down into the gear on the cam if the spacing is wrong causing binding.
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 22
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Would I be better off getting a new intake? I don't want to just throw parts at the problem, but I've been messing with this issue for a couple of weeks now not beyond spending a couple hundred bucks to get the car back on the road.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,170
From: Hermosa
This is what I'm worried about. I've tried running the distributor with and without the gasket in place and even tried stacking a few gaskets to create a shim to see if it was a depth issue. Play up and down seems OK and if I loosen the distributor there is a little play around the neck, but I'm concerned there is an angle situation as you mentioned. Do you think loosening the intake bolts, bumping the motor a few times and retorquing might help? How did you remedy your situation?
In your case I would take the dist apart and remove the drive gear and shaft and determine in which direction it is being forced, if that is the problem.
Loosening the intake manifold and then bumping it in the proper direction with say..a rubber mallet may work, or it may just induce a leak. Hard to say.
First take the dist apart and determine what is causing the noise. It should be apparent by new shiny wear on two adjacent surfaces. Maybe some scoring as well. Then decide what is needed to fix it.
Melting Slicks
Joined: Apr 2009
Posts: 2,632
Likes: 112
From: Great Plains Iowa
Its your alternator's front bearing that is about ready to seize OR the alternator fan is rubbing against the front of the housing. Remember a distributor spins at half the crank speed but an alternator spins about twice as fast.
Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 22
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Thread Starter
Heel & Toe
Joined: Apr 2009
Posts: 22
Likes: 0
SO I took apart the distributor and it looks like i have wear on the bottom bushing towards the front of the car and wear on the top bushing towards the rear corner... so I'm guessing the intake is either not level, or needs to move forward a bit.
Question is can I loosen up the intake and bump it forward with a rubber mallet, or should I just redo the whole thing? This is the part of hot rodding that is not fun :-/
Question is can I loosen up the intake and bump it forward with a rubber mallet, or should I just redo the whole thing? This is the part of hot rodding that is not fun :-/