Help me ID this distributor

B

Bad Ass Black Trucks

New member
I was refurbing my stock distributor following Syclone#1721's how-to post and didn't think I needed to replace anything but the pickup. After looking a little closer at the how-to thread, I realized that my magnet was also cracked. Bummer since the magnet cannot be purchsed without the shaft and it's about $70.

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But I also have an aftermarket distributor that I picked up on e-bay. I thought it was an MSD, but I am not sure. It did not have a cap or rotor when I got it.

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Anybody know what it is? It does not have a bronze distributor gear and a stock replacement cap and rotor fit. The drive shaft is larger diameter than stock.

As far as I can tell, the only thing wrong with it is that the drive shaft is not perfectly straight. I think I can get a machinist to true it up but I am worried that the housing might be trashed.
 
M

MoJo

New member
Re: Help me ID this distributor

I would trash that distributor. You can get a new Top Street Performance #6651-R distributor for $60.
 
M

MoJo

New member
Re: Help me ID this distributor

I have A TSP 6651-R billet ready to run distributor in my Chevrolet 1991 4.3l V6 with a HV oil pump and Comp Cams hydraulic roller camshaft and it has performed flawlessly for 8,000 miles so far, after rebuilding the engine. Before installing the TSP distributor, I recommend that you replace the ICM that comes in the TSP distributor or use your old one because the ICM in the TSP distributor is an unknown brand. I did not know whether I had to or not but I replaced the ICM with an AC Delco D1943A module in my TSP distributor before I installed it. The TSP distributors have a .500" diameter shaft with a case hardened gear. Skip White sells the TSP 6651-R Ready to Run billet distributors for $46 plus shipping on e-bay. . .

www.topstreetperformance.com

.
 
B

Bad Ass Black Trucks

New member
Re: Help me ID this distributor

Can you tell if I have a TSP or MSD housing ?

I might go ahead and pick one up at $46 + shipping cause it's ready to go.

Is there any way to test the ICM? Not sure if I should swap the stock one that was on the truck or leave the one on the TSP. It had other issues that kept it from running right so I have no idea if the module is good or not.
 
M

MoJo

New member
Re: Help me ID this distributor

I have never compared a MSD Ready to Run distributor and a TSP Ready To Run distributor side by side. But for $46 compared to $300 , you can at least justify buying a new AC Delco D1943A module. Don't run some brand of mega volt coil or you will be asking for premature module failure. The AC Delco D503A coil is more than adequate and is compatible with the AC Delco ICM. I also replaced the funky looking TSP red distributor cap with an AC Delco D580A black cap that has brass electrodes, just for the appearance. . The TSP distributor cap also has brass electrodes and I am sure it is a excellent distributor cap, but I don't like red.

I recommend using Arctic Silver 5 Thermal Compound instead of the supplied silicone dielectric grease on the ICM heat sink plate. "Di-electric" means it is a insulator . The ICM needs a heat conductive compound that will conduct heat away from the ignition module. Also use Arctic Silver 5 on the module mounting screws for a good ground and resistance to corrosion . Arctic Silver 5 cost $4 at Amazon.

I had concerns about the module that came in the TSP Ready To Run distributor and that is why I replaced it. The TSP 6651-R "Ready to Run" distributor may work perfect out of the box, without replacing those parts.
 
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bezerk

bezerk

New member
Re: Help me ID this distributor

hood put some pics in a threas here comparing msd and knock offs from ebay, the results were that they are alomst identical and both look like quality work.
 
SY-1193

SY-1193

Active member
Re: Help me ID this distributor

MSD Distributors have allen heads holding the magnet on. Aftermarkets have phillips heads holding the magnet. (both use phillips on the module) One of the key things I look for.
 
Throws

Throws

Active member
Re: Help me ID this distributor

bezerk said:
hood put some pics in a threas here comparing msd and knock offs from ebay, the results were that they are alomst identical and both look like quality work.
Click to expand...

Probably made in the same factory.

Got links to the thread Hood put up?

-P
 
bezerk

bezerk

New member
Re: Help me ID this distributor

well, he took pics in a thread about the same time, go search for it yourselve :D
 
sytyguy

sytyguy

Moderated User
Re: Help me ID this distributor

The major quality difference is the "slop" in the shaft of the TSP unit. It has "slop" similar to the stock unit, whereas the MSD is much tighter (not tight to spin, but vertical "slop"). I would count this as a Pro for the MSD unit, but not enough of one to justify paying $50 more, let alone $250 more. There are other differences, but none that really make that big of a....well.....difference.
 
M

MoJo

New member
Re: Help me ID this distributor

The "slop" (thrust) of the distributor shaft should be .015" - .020" for oil clearance and thermal expansion. of the distributor housing. Distributors come with as much as .060" thrust and the timing will vary one degree for every .015" thrust. You can buy hardened thrust washers in various thicknesses to blueprint the thrust clearance if necessary. The roll pin holes in the shaft and gear can only be aligned and installed in one location and that will determine the thickness of the thrust washers required to correct the thrust.

Mr. Gasket #2820 hardened distributor gear shim kit contains... 2-.010" washers. a. 020" washer and a .050" washer for a .500" diameter shaft. .The end play on my TSP 6651-R Ready to Run Pro-billet distributor was .020" out of the box with two .010" shim washers. That is where is should be so I did not correct it. .
 
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sytyguy

sytyguy

Moderated User
Re: Help me ID this distributor

MoJo said:
The "slop" (thrust) of the distributor shaft should be .015" - .020" for oil clearance and thermal expansion. of the distributor housing. Distributors come with as much as .060" thrust and the timing will vary one degree for every .015" thrust. You can buy hardened thrust washers in various thicknesses to blueprint the thrust clearance if necessary. The roll pin holes in the shaft and gear can only be aligned and installed in one location and that will determine the thickness of the thrust washers required to correct the thrust.
Click to expand...
Shoot that to MSD....they might wanna know. :lol:
 
M

MoJo

New member
Re: Help me ID this distributor

I am sure the engineers at MSD are aware of that. The manufacturers of GM and aftermarket distributors don't feel like as much as four degrees timing variance is a big deal. GM and aftermarket manufacturers have thrust washers available that will allow a technician or car owner to correct manufacturing tolerances.

I bought dozens of hardened shims from Chevrolet dealerships in order to correct the old pre-1967 cast iron point type distributors that have a .491" diameter shaft. . The cast iron point type distributors often come with as much as .120" thrust and they can be reduced to as little as .012" for oil clearance with a zero timing variance (spark scatter). . The thrust clearance on those distributors was especially important when converting a point type distributor to a Pertronix breakerless system.
 
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