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The MSD distributor you have has an iron gear. If the engine has a roller cam, it most likely requires a melonized steel or composite gear - which is why the iron gear got destroyed. It would be a good idea to talk to the previous owner regarding the cam, or just say a prayer and toss in a melonized steel gear.
 

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Dimples
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These guys are pointing you in the right direction.

Things can always go bad on you, but I’ve seen similar situations in the past, and it’s never led to catastrophic engine failure. Just stress, lol. Good luck! I think you’ll be ok.
 

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You lucked out if the distributor gear didn't kill the cam gear. You also don't appear to have a seized distributor.
You're definitely going to want to check that the oil pump rotates.
Me personally, I'd be pulling that oil pan to scrutinize things...... I'd trust nothing to chance or good luck on this deal.
 
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Discussion Starter #24
Tomorrow I will remove the oil pan and check the oil pump since we are not getting any reading on the oil pressure gauge. The oil pressure sender unit is giving me 19K ohms whereas 10-78 ohms should be normal. It does not matter whether the unit is installed or not. Even when unplugged I measure 19K ohms between the stud and the threads where it is supposed to ground from. Perhaps something might be wrong with the pump all along.
 

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You are not getting oil pressure because you have removed the distributor. The crankshaft turns the camshaft by way of the timing chain. The camshaft turns the distributor by way of the driven gear that is part of the cam turning the gear on the bottom of the distributor. The oil pump is driven by a 5/16" hex shaft that fits into the bottom of the distributor shaft and the top of the oil pump. No distributor to turn the hex shaft = no oil pump rotation and no pressure.
 

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Discussion Starter #26
You are not getting oil pressure because you have removed the distributor. The crankshaft turns the camshaft by way of the timing chain. The camshaft turns the distributor by way of the driven gear that is part of the cam turning the gear on the bottom of the distributor. The oil pump is driven by a 5/16" hex shaft that fits into the bottom of the distributor shaft and the top of the oil pump. No distributor to turn the hex shaft = no oil pump rotation and no pressure.
Sorry for the misunderstanding, but I meant that the oil pressure sending unit was already giving odd readings before we were driving. But since we have had the engine idling for a few hours total over the past months and the oil level was always above add we thought it was OK and ignored the faulty sender.
 

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Steve, is this a fairly fresh engine ? I wonder if they didn't get the oiling right on the dizzy gear. And you simply MUST find out what cam is in the engine so you can choose the proper gear. I'm thinking the pan has to come off to check the oil pump anyway. Anything else is just a coin flip. LSG
 

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Steve, is this a fairly fresh engine ? I wonder if they didn't get the oiling right on the dizzy gear. And you simply MUST find out what cam is in the engine so you can choose the proper gear. I'm thinking the pan has to come off to check the oil pump anyway. Anything else is just a coin flip. LSG
If the cam gear looks good can't he just put a melonized gear in? It sounds like they're pretty universal.
 

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Discussion Starter #29
Steve, is this a fairly fresh engine ? I wonder if they didn't get the oiling right on the dizzy gear. And you simply MUST find out what cam is in the engine so you can choose the proper gear. I'm thinking the pan has to come off to check the oil pump anyway. Anything else is just a coin flip. LSG
Yes it actually is a fresh engine! The previous owner bought this at a garage at it has only ran outside of the car. We actually drove less than 30 miles with it.

Can we determine the type of cam that we have after removing the oil pan?
 

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Dimples
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You'll likely need to remove the timing cover and chain and hope for some markings that would identify the cam. Or I suppose you could pull the intake manifold and see if you have roller lifters. That would indicate a later model cam that would likely need the melonized gear.

Note: I am not an expert at this stuff, so don't hold me to it. I have personal experience, but without looking at your engine myself, I sure don't want to give you bad advice.
 

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You'll likely need to remove the timing cover and chain and hope for some markings that would identify the cam. Or I suppose you could pull the intake manifold and see if you have roller lifters. That would indicate a later model cam that would likely need the melonized gear.

Note: I am not an expert at this stuff, so don't hold me to it. I have personal experience, but without looking at your engine myself, I sure don't want to give you bad advice.
I just added a 5.0 EFI setup to my 289 which had a cast flat tappet cam, everything I've read said a melonized gear works with about anything so thats what I installed on my distributor.

"So now with three different types of cam core materials – cast iron flat tappet cams, ductile iron hydraulic (and some mechanical) rollers, and steel mechanical (including a few hydraulic) roller cams. As it currently stands, there are a total of four different distributor gears you can use – stock iron, bronze alloy, composite, and a melonized gear. There’s been plenty of confusion over which distributor gears are compatible with these different camshafts.


The simplest, all-encompassing, and easiest answer is melonized distributor gears will work with all three types of camshafts – even the steel roller camshafts. To make this a little less confusing, we’ve included a chart that will itemize each cam material and which distributor gear will work with that material. In the course of our research, there has been some significant confusion around this point, and there are published stories on the internet that state melonized gears can only be used with a SADI, or ductile iron cam. That is not true.


According to Godbold, the melonized heat treatment gives the gear a very slick surface, which makes it cozy with any cam gear material, period. To make this even easier, Comp now offers a line of melonized distributor gears for both small- and big-block Chevrolet applications and also for the Ford. Right now, for the GM engines this is limited to just the 0.500-inch shaft diameter distributors such as those from MSD"

So to me, if he can visually see the cam gear survived, just install a melonized gear and be done with it.
 

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Steve, if the cam cannot be identified, I might try the Mellonize gear. They work with lots of cams, but not with all of them, but its a good choice if you're shooting in the dark. But you should also check the plug behind the distributor and be sure it is an oiler. LSG
 

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Discussion Starter #34 (Edited)
I just added a 5.0 EFI setup to my 289 which had a cast flat tappet cam, everything I've read said a melonized gear works with about anything so thats what I installed on my distributor.

"So now with three different types of cam core materials – cast iron flat tappet cams, ductile iron hydraulic (and some mechanical) rollers, and steel mechanical (including a few hydraulic) roller cams. As it currently stands, there are a total of four different distributor gears you can use – stock iron, bronze alloy, composite, and a melonized gear. There’s been plenty of confusion over which distributor gears are compatible with these different camshafts.


The simplest, all-encompassing, and easiest answer is melonized distributor gears will work with all three types of camshafts – even the steel roller camshafts. To make this a little less confusing, we’ve included a chart that will itemize each cam material and which distributor gear will work with that material. In the course of our research, there has been some significant confusion around this point, and there are published stories on the internet that state melonized gears can only be used with a SADI, or ductile iron cam. That is not true.


According to Godbold, the melonized heat treatment gives the gear a very slick surface, which makes it cozy with any cam gear material, period. To make this even easier, Comp now offers a line of melonized distributor gears for both small- and big-block Chevrolet applications and also for the Ford. Right now, for the GM engines this is limited to just the 0.500-inch shaft diameter distributors such as those from MSD"

So to me, if he can visually see the cam gear survived, just install a melonized gear and be done with it.
Thanks! I will order a melonized gear then. Any suggestion on where I can buy this? Can't find any on summitracing. The distributor I have is the MSD PN8478, 0.501" shaft.
 

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Discussion Starter #35

I am looking at this one.
 

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Edit, just saw that your distributor has an odd size shaft. Your dizzy had a cast gear when new
 

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I would try a composite gear, rather than a melonized one, since we don’t know what cam it is. As pointed out above, the end of the cam might have numbers etched into it. Remove the timing cover and the cam retainer and see. From there we may be able to track down what the cam is. Was there no paperwork from where the PO had the engine built?

also, don’t worry about the MSD stuff. They make a fine product. Just make sure that you have good, clean grounds on everything.
 

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Steve, while your cleaning and checking things, check the plug in the gally behind the dizzy. Frequently this plug is incrrectly replaced with a solid, and then the gear has no oil supply. LSG
 

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Discussion Starter #39
Steve, while your cleaning and checking things, check the plug in the gally behind the dizzy. Frequently this plug is incrrectly replaced with a solid, and then the gear has no oil supply. LSG
Not sure what you mean by "gally". I am not familiar with most of these components.
 

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Not sure what you mean by "gally". I am not familiar with most of these components.
Your engine block has oil "galleys" that are passageways for the pressurized oil to pass through. There are diagrams on the internet that show the galleys in a 351W block. One of the lengthwise galleys ends right behind the distributor and there is a plug in the block to hold the oil in the galley. Some people drill a small hole in this plug to allow oil to spray out onto the distributor and cam gears.
 
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