MSD 8595 installation on 390 FE

[amdscooter]

Quick question for the crowd. My new Mallory 8595, blaster2 coil and plug wires arrived this week and I finally had some time today to install them. I got under the hood this afternoon, pulled the plugs, got the crank to TDC on #1 and yanked the stock distributor. I gooped up the cam gear with Cam assembly lube and went to installing the new distributor. It slipped in fine but was really tight when it got down to the gear mesh on the cam. So much so I had to tap it in with mallet. The distributor body itself rotates freely. Cranking the motor over with the coil disconnected, it's noticeably cranking slower than before. I cannot locate the info now.. but I seem to remember reading that there are at least 3 different sets of gears available for this unit. IIRC they are different for hydraulic & roller flat tappet cams. Mine came with what appeared to be cast iron.. but to be honest I'm not sure. I figured since my cam is very similar to the stock (Comp 268H hydraulic flat tappet) it would not be an issue. I'm pulling it out tomorrow regardless. So.. on to the questions.

Would using the wrong gear style cause the tight gear mesh I'm experiencing or should any of them fit the same? Do you guys think this is a defective unit? As I stated above the distributor housing rotates freely (like if you were twisting it to adjust the timing). And it's nearly perfectly centered in the intake bore.. no interference issues there and the old one fit fine as well. I seem to remember reading that the bronze gear worked with any type of cam, would it be worth it to get a bronze gear from MSD? If yes is replacement done by simply punching out the roll pin and installing the new gear in the same location with a new pin?   

 

[jayb]

That distributor comes with the cast iron gear.  Regardless of material, all the gears will be the same.  Can you take some measurements on the MSD gear and the original gear and see if there are any differences, like thickness of the teeth or diameter of the gear?  How about diameter of the bottom shaft that goes into the block?  Also, make sure you check the dimension shown in the MSD instructions for the distance from the gear to the distributor body.

If you had to tap the distributor to get it in place, does it also not want to come out?  When you take it back out, look on the gear and the bottom shaft and see if you can see evidence of binding or tightness.

Also when you pull the distributor out, take a look down the hole at the oil pump driveshaft.  Does it look OK down there?  Is there a burr on the driveshaft, like the distributor wasn't lined up quite right with the hex on the driveshaft and galled it up or something like that?  After the distributor is out I'd put a 5/16" 6 point quarter inch socket on an extension, put it down the hole and spin the driveshaft to make sure it spins freely.  Tape the socket to the extension so it doesn't come apart when you put it in the hole.  And don't force it onto the oil pump driveshaft or you might have a lot of trouble getting it back off.

If you can observe some wear once you have the distributor out, or find some differences in the measurements it should clue you in to where the problem is.  I have to say I find it hard to believe that the distributor being installed puts such a drag on the motor that it turns over slower.  If that is really true, something is way, way too tight in there...

[funsummer]

When you have your distributor out could you do me a favour?
I need to determine the correct height of the oil pump shaft in relation to some part of the block.
Be very much appreciated.
reason for this i have fitted a main cap girdle and i think i may have a oil pump shaft that is to short.

With your dizzy check clearance on the china wall at front of valley, may be twisting dizzy of line.
I have a 390 block and i had to file the china wall back a bit as my dizzy was just catching on the block casting. Was fine with stock dizzy, aftermarket dizzy was contacting it. Was catching in last 1/2" of installed height.

[amdscooter]

^^^ Thanks for the suggestions. Now that I know all the gears are the same dimensions I'm really curious to see WTf is going on down there. It's still in the car as I had to wrap up earlier than I wanted. I'll be pulling it tomorrow if all goes well. After i get it out I'll dust off my caliper and take some measurements of the gear. I usually use a nut driver to turn the pump drive shaft.. I used a lot of "Right stuff" on the pan and don't wanna ever have to go fishing for sockets!

[amdscooter]

When you have your distributor out could you do me a favour?
I need to determine the correct height of the oil pump shaft in relation to some part of the block.
Be very much appreciated.
reason for this i have fitted a main cap girdle and i think i may have a oil pump shaft that is to short.

With your dizzy check clearance on the china wall at front of valley, may be twisting dizzy of line.
I have a 390 block and i had to file the china wall back a bit as my dizzy was just catching on the block casting. Was fine with stock dizzy, aftermarket dizzy was contacting it. Was catching in last 1/2" of installed height.

I can probably get the back end of my caliper down there and get the height from the top of the shaft to the top of the bore the upper end of the shaft sits in where it slides into the bottom of the distributor gear. Would that do?

As far as the dist housing itself, it seems to fit fine and rotates freely. So I don't think there are any interference issues with the block. thanks for the suggestion.

[amdscooter]

. . . Also, make sure you check the dimension shown in the MSD instructions for the distance from the gear to the distributor body.. . .

Just re-read the instructions.. no mention of a pre measurement. I downloaded the pdf from MSD's website as well.. it matches what came in the box. Do you by chance have a link to the addendum?

[funsummer]

When you have your distributor out could you do me a favour?
I need to determine the correct height of the oil pump shaft in relation to some part of the block.
Be very much appreciated.
reason for this i have fitted a main cap girdle and i think i may have a oil pump shaft that is to short.

With your dizzy check clearance on the china wall at front of valley, may be twisting dizzy of line.
I have a 390 block and i had to file the china wall back a bit as my dizzy was just catching on the block casting. Was fine with stock dizzy, aftermarket dizzy was contacting it. Was catching in last 1/2" of installed height.

I can probably get the back end of my caliper down there and get the height from the top of the shaft to the top of the bore the upper end of the shaft sits in where it slides into the bottom of the distributor gear. Would that do?

As far as the dist housing itself, it seems to fit fine and rotates freely. So I don't think there are any interference issues with the block. thanks for the suggestion.

That measurement you have suggested be fine.
Thank you very much.
My dizzy still rotated easy, was just being pushed by the china wall. Have a look at yours when its out.

[bartlett]

I would be real careful about taping ect on the dizzy to install it. You need to be sure the oil pump drive shaft is just right to get the dizzy to drop. Like jay said you drop it in and if it don't drop all the way in you pull it out and turn the oil pump shaft a little bit and retry. I would also do a side by side of the old and new to besure  you have the correct dizzy and or gear height ect. We all know weird things can happen. maybe swap gears and see if it fixes the issue. personaly I would never try it tight. you risk grinding the cam gear and then your infor a big job.

[fe66comet]

I had to get a gear from comp cams just for my FE can. The one for the stock can was a slightly different pitch which would cause binding.

[amdscooter]

I would be real careful about taping ect on the dizzy to install it. You need to be sure the oil pump drive shaft is just right to get the dizzy to drop. Like jay said you drop it in and if it don't drop all the way in you pull it out and turn the oil pump shaft a little bit and retry. I would also do a side by side of the old and new to besure  you have the correct dizzy and or gear height ect. We all know weird things can happen. maybe swap gears and see if it fixes the issue. personaly I would never try it tight. you risk grinding the cam gear and then your infor a big job.

Had kinda a restless night thinking about what a "not so smart" move it was to tap it in. Soon as I'm done with my coffee I'm headed under the hood... and switching to beer.  Once I get it out I'm planning on doing a side by side with the old and measuring the placement and overall dimensions of the gear. I'm also going to see how well the old pump drive shaft I have leftover from the rebuild fits. As easy as it twists it's either tight on the gear -or- the oil pump drive shaft. Which should engage first.. the pump shaft or the gear on the cam? IIRC it was the shaft on mine as I was still able to turn the rotor while trying to get the shaft to engage.

I've already had not so great thoughts about the drive shaft being stuck.. breaking the retaining clip and coming out with the dizzy just far enough to fall back into the abyss. So slow and easy is the motto for today under the hood work with timeouts for the prayer mat hoping I did not just buy myself a lot of work and additional $$$ by being impatient.

[fe66comet]

It will engage the shaft first then the gear. Opposite of a Chevy. I would call comp cams and ask. The clip if it falls off ends up in the pan.

[amdscooter]

It will engage the shaft first then the gear. Opposite of a Chevy. I would call comp cams and ask. The clip if it falls off ends up in the pan.

^^^ That'd be a nightmare scenario for me. With my luck I'd be able to recover either the shaft or the clip.. but not both. I used "Right Stuff" on both sides of the pan gasket, I could probably take every bolt outta the pan at this point and it'd never budge. Not to mention how "fun" it would be to fish around in the pan. What with there being so much movement on the pan with the cossmember and oil scupper fighting you for every inch of access.....   

[fe66comet]

I honestly doubt the clip is an issue, I am leaning toward the gear, I have myself ran into this problem with aftermarket parts.

[jayb]

Here are a couple of sets of instructions, one from MSD and one from Ford, showing the correct distance between the distributor gear and the housing, plus end play.  They are not the same, so I have to assume that there is some difference in the distributors or gears.  This measurement is not your problem, but you should probably check it anyway.  Note that when you make the measurement from the bottom of the gear to the housing, the shaft should be pushed up into the distributor as far as possible:

[jayb]

It will engage the shaft first then the gear. Opposite of a Chevy. I would call comp cams and ask. The clip if it falls off ends up in the pan.

^^^ That'd be a nightmare scenario for me. With my luck I'd be able to recover either the shaft or the clip.. but not both. I used "Right Stuff" on both sides of the pan gasket, I could probably take every bolt outta the pan at this point and it'd never budge. Not to mention how "fun" it would be to fish around in the pan. What with there being so much movement on the pan with the cossmember and oil scupper fighting you for every inch of access.....   

I hate to admit it, but I've put a lot of miles on one of my engines with that clip and an extra oil pump driveshaft rattling around in the pan LOL!  It's creepy, but it usually doesn't hurt anything.  Neither one of those items is small enough to get through the screen on the oil pump pickup.  This happened to me back in the early 1980s with the 428CJ in my '68 Shelby.  The shaft was seized in the bottom of the distributor, and it dragged the clip off the shaft as I was pulling the distributor out.  Then, just as I got the distributor out and the shaft was still in the hole, it dropped free, all the way down to the pan.  I could not get it out of there, so I ended up bumping it to the side with a long screwdriver so it was out of the way, gluing a new shaft into the bottom of the replacement distributor, and installing it.  Not that I'm recommending that, but the car was my daily driver back then, and I had to get to work the next day.  The shaft sat down there harmlessly all summer, and through a fair amount of WOT action on Friday and Saturday nights.  When I pulled the motor over the winter and tore it down, there was the driveshaft and the clip, just sitting in the pan.  I'm sure the windage tray kept it out of the reciprocating assembly.  Maybe I was lucky, but I think if you lose it down there its not a huge disaster...