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FE Power Forums => FE Technical Forum => Topic started by: fairlaniac on March 09, 2020, 07:54:48 PM

Title: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 09, 2020, 07:54:48 PM
I have a MSD Pro Billet 8594 that I ran in my 390. So I had the local machine shop install a new steel gear for my new 427 build with roller cam. It will not drop in. It gets hung up on the land and the bottom of the shaft doesn't seem to line up and drop in the pilot hole. Now it will not even drop in the 390 block it once fit? So I try a points distributor I have lying around. It drops in. I mic'd the shaft end and body. Both are exactly the same. I chuck the distributor up and put a dial indicator to it to see if the shaft got bent at the shop. Zero run-out. Thought not the issue I tried a duplicate ARP oil pump shaft in the end. It slides in properly. I measured into the hole and got the dimension from the top of the opening in the block to the land and it measures the same as the point where the distributor stops going in. I'm pretty certain it is hitting the land and just not hitting the hole. Any ideas? This is so freaking basic I cannot believe it won't drop in. I also snap gauged the pilot hole and it is a few thou bigger than the diameter of the shaft. What could be wrong? Only difference as stated a new steel gear installed. it is the same o.d. as the cast gear. I also turn the crank to see if it will drop but it doesn't?

Thanks!
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: cjshaker on March 09, 2020, 08:06:26 PM
Did you use a distributor to locate the intake manifold? If not, it can be off enough to bind the distributor up, or just stop it from dropping in. That doesn't explain why it won't drop into the old engine though, but it's still something to check. Have you measured and eye-balled the gear to make sure it's the same diameter, tooth size etc? One last thing to check would be the hole size in the intake. I forget what intake you used, but aftermarket parts are always susceptible to machining errors.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 09, 2020, 08:09:26 PM
I shoulda said, the manifold is not on yet. I was making sure the distributor went in before I set the manifold. I also mic'd the diameters of the new and old gear, same.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: Cyclone03 on March 09, 2020, 08:44:43 PM
If the only change was the gear something is wrong there. Pitch,diameter ,upside down?
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: Stangman on March 09, 2020, 09:01:14 PM
Gotta be gear did you supply it or did they. Do you have the old one to see.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: C6AE on March 10, 2020, 12:23:00 AM
If you have an old cam, hold the distributor w/gear up and engage it. They are 90° to each other and you may be able to mike the overall distance outside cam gear to outside dist gear? Try it with the both distributors. A problem may become apparent.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 10, 2020, 04:46:50 AM
If you have an old cam, hold the distributor w/gear up and engage it. They are 90° to each other and you may be able to mike the overall distance outside cam gear to outside dist gear? Try it with the both distributors. A problem may become apparent.
The 390 is pretty much in tact for another project.

I may just pull the distributor apart, put the gear on the shaft and try to drop it in. With the body off I might better see what is going on?
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 10, 2020, 04:48:16 AM
Gotta be gear did you supply it or did they. Do you have the old one to see.

I supplied the Crane gear per my inquiry in this post. http://fepower.net/simplemachinesforum/index.php?topic=8418.0 (http://fepower.net/simplemachinesforum/index.php?topic=8418.0)
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: blykins on March 10, 2020, 04:49:54 AM
I've seen guys mushroom the end of the shaft when they pull the old gears off.

Oh, another thing....

I've also seen it where the engine was leaning one way hard enough that the pump drive won't center in the hole and the distributor won't line it up when you try to drop it in.  I've had to take a little screwdriver and see if I can center the shaft in the hole, then drop the distributor in.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 10, 2020, 06:48:33 AM
I've seen guys mushroom the end of the shaft when they pull the old gears off.

Oh, another thing....

I've also seen it where the engine was leaning one way hard enough that the pump drive won't center in the hole and the distributor won't line it up when you try to drop it in.  I've had to take a little screwdriver and see if I can center the shaft in the hole, then drop the distributor in.

It doesn't look mushroomed but I did run a file around the edge to make sure.

The end of the shaft isn't going below the top surface of the hole to even catch the oil pump drive.

I think if I pull it apart and put the gear on the shaft and drop it in I'll see where my issue lies. I assume if I pull off the collar and the gear the shaft comes out of the body? No other part should unexpectedly fall out I assume?

This is just freaking weird.

thanks,
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: 1964Fastback on March 10, 2020, 07:07:55 AM
Is the shaft too big in diameter, like an FT shaft going into an FE block?

Pat
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 10, 2020, 07:34:30 AM
Is the shaft too big in diameter, like an FT shaft going into an FE block?

Pat
Same diameter and it will not go back into the block it came out of.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: FordEver on March 10, 2020, 07:37:26 AM
All off the above possible plus , I had replaced that  push in oil plug with a threaded one, it stuck out too far, removed it ground it down, then dropped in.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 10, 2020, 07:50:47 AM
All off the above possible plus , I had replaced that  push in oil plug with a threaded one, it stuck out too far, removed it ground it down, then dropped in.
Solid lifter block. No plug behind distributor.

Thanks!
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: cjshaker on March 10, 2020, 09:54:26 AM
Try putting some machinists dye on the base, gear and shaft. You can try to install it then, twisting the shaft and wiggling the base, pull it back out and see if you can see where the interference is. Just a thought, because it has to be hitting someplace.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: sixty9cobra on March 10, 2020, 10:03:16 AM
did you compare the gears? upside down, wrong Dia, wrong rotation?
                       Harry
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: Rory428 on March 10, 2020, 10:23:42 AM
I can`t believe that nobody has mentioned this, but did you try rotating the crankshaft while holding the distributor downward? Often I have had a distributor not want to drop down, simply because the dist. gear and oil pump drive were not aligned. Usually turning the damper 1/8th of a turn or less is enough to make everything fall into place. The fact that all your measurements are good, and it didn`t drop into the old engine again makes me think that is all it is. Either that, or perhaps the oil pump drive rod lifted out of the oil pump, and is sitting cockeyed and too high, but pretty unlikely that is the case with 2 different engines.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 10, 2020, 10:49:35 AM
I can`t believe that nobody has mentioned this, but did you try rotating the crankshaft while holding the distributor downward? Often I have had a distributor not want to drop down, simply because the dist. gear and oil pump drive were not aligned. Usually turning the damper 1/8th of a turn or less is enough to make everything fall into place. The fact that all your measurements are good, and it didn`t drop into the old engine again makes me think that is all it is. Either that, or perhaps the oil pump drive rod lifted out of the oil pump, and is sitting cockeyed and too high, but pretty unlikely that is the case with 2 different engines.
I mentioned turning the crank, last comment in my opening post. Pump drive is in pump.
Thanks!
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: HarleyJack17 on March 10, 2020, 01:21:36 PM
It sounds like you are on your game but it can be easy to miss things, especially if you start going down a single road.
Make certain the pump drive is installed in the correct direction...its been done before.
Is the cam in the correct place/torqued? This is a long shot but possible-think you may have eliminated this with the old dizzy.
When it bottoms out is it free-or stuck? I had to clearance a little on my pertronix-again I think you checked this.
Verify the gear is installed at the correct depth on the dizzy- If not the gear will hit the pump drive deck and dizzy not fully seat. I have done this and it was costly.
Is the shaft in the dizzy possibly bent or offset?
Again, I am sure you have checked all this but it may not hurt to make a list and go line by line checking it off.
Find the root problem or it will show up later and likely in a costly way.
You are not the only one that runs into things like this...TRUST ME! 
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: Falcon67 on March 10, 2020, 01:40:49 PM

It doesn't look mushroomed but I did run a file around the edge to make sure.

The end of the shaft isn't going below the top surface of the hole to even catch the oil pump drive.

I think if I pull it apart and put the gear on the shaft and drop it in I'll see where my issue lies. I assume if I pull off the collar and the gear the shaft comes out of the body? No other part should unexpectedly fall out I assume?

This is just freaking weird.

thanks,

I keep distributor bodies without gears on the shafts just for similar issues - tweaking the position of the pump shaft to let the real dist. drop in, etc.  If possible, mic or caliper the shaft from the gear down to the end to make sure it's a consistent diameter.  If the shroomed the shaft getting the old one off, it's be hard to get an new gear on anyway. 
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: fairlaniac on March 10, 2020, 05:01:59 PM
Mushroom is the winner! I moved my dial gauge to the very end of the shaft and it was out. Dressed up the end a little @ 3/32" from the end up and it took car of it. It was barely catching the edge of the hole.

Thank you all and I hope others as well as me learned a little something.
Title: Re: I'm baffled! MSD distributor will not drop in?
Post by: turbohunter on March 10, 2020, 05:06:52 PM
Thanks for doing the work Doug.
Something else to keep an eye on.