How much clearance should there be in between the oil pump shaft and the drive gear tag on the distributor? My distributor bottoms and have approximately .120” before the base of the distributor contacts the timing cover.
Are you sure the slot and tab are engaging? It doesn't sound like they are to be that far apart. I can't imagine a stock oil pump and distributor being that far apart. Every distributor I've ever seen will drop in and bottom out on the front cover. Do you have a spare front cover you could verify it with? Did someone swap an HEI shaft into a non-HEI housing? I think they are longer but a lot more than .120"
I have the oil pump cover assembly from TA and an MSD pro billet distributor. I have .064” gap in between the cover and distributor.
I have the oil pump cover assembly from TA and an MSD pro billet distributor. I have .064” gap in between the cover and distributor.
Just wondering about the differences between the 350 oil pump gears and the 455 oil pump gears, specifically the DRIVE gear. Might the shaft be slightly longer on the 455 than the 350? Is it possible to install the 455 gear in a 350? Might just prevent the distributor from bottoming? I don't know the answers to any of those questions, but I thought it worth asking.
I bought this cover from TA it’s their high performance cover assembly. I’ll have to give them a call on Monday and ask how far from bottomed it should be. I can easily make a shim out of brass or aluminum. Moroso makes them out of nylon as well, but only 3 sizes.
Larry the 455 gears are about a 1/4” taller that the 350 gears. The 455 gears come with a spacer for the 350 with the high volume set up.
My bad it’s been a long day. I believe the shafts are the same size. I have a high volume pump somewhere along with a stock one somewhere. I’ll check the length when I find them.
There should be ZERO clearance between the base of the distributor and timing cover. The only place I can think of a “tolerance” stack up would be, the oil pump drive gear is sitting too high in the oil pump pocket (pocket machined too deep) BUT that would cause excessive gear end play. The high volume and standard oil pump drive gear shafts are the same length, OR they should be. Other issue might be some garbage on the distributor shaft/oil pump drive tang, ( see pictures)
Everything is brand new. The end of shaft for the pump looks ok as well as the bottom of the distributor. I have another distributor I put that one in and see if that bottoms out on the cover. If that doesn’t bottom out I’ll call TA on Monday. Maybe the clearance is from when TA machined the cover.
Sounds good, critique every component, remember there should be NO gasket or shims between the base of the distributor and timing cover. The ONLY thing I can think of that MAY be askew is too many shims between the distributor drive gear and the bottom of the distributor shaft That would push the distributor shaft all the way to its lowest position causing the shaft to fully engage the oil pump BEFORE the distributor body has seated against the timing cover, but I’ve never run into that scenario. Hers a pic of what shim and where I’m talking about.
No shims in between housing and gear on the MSD distributor(pics). I installed my Mallory distributor and it’s fits the same. Time to call TA.
Could be the gear, or even the gear position on the shaft. The very last place I would look is TA. Have you a stock distributor to try?
It should fit snug to the timing cover, I have the large gears in, it could be the o ring on the distributor holding it up from dropping in all the way put a little bit of silicone on the rubber to aid it slipping in. The MSD dist for the 350 is 8548 should drop all the way in. It is probably the shaft sticking on the way in. don't forget, the dist shaft will turn to the right when dropping so you have to guess where to put that pump shaft before dropping in, oil it up and try again. Clean up that shaft part that slip into the timing cover looks like a lot of crud on it. On pic of top of distributor I have two white marks one is the line up to the plug and the other one is where the distributor is after you shove it in. It moves to the mark on left so you need to shove it in almost pointing to number two on dist and it ends up at #1 slightly past on mine. In between the two posts to start with. Once I knew where the proper timing was for my motor I took a screwdriver and made a ding in both the distributor and timing cover at same time. That way I know exactly where it needs to be before starting up. From there I tweek the timing to where I need it to be. This worked perfectly when I put in the new cam I ended up being at 36 on the timing so had to back down from there but was good enough to get car started.
No o-ring on distributor yet. Was test fitting it to make a new hold down bracket. No gunk on anything there’s not a one used part on the motor. I guess I should of put this in my other thread “ my 350 build”.
