Distributor / oil pump problem

[dougskewl]

New to the mustang platform this year. First race out we broke a distributor gear in practice. We tried to turn the oil pump but could not. Loaded it up took it home and pulled motor. All the bearings were fine but we did find a piece of the dist. gear in the oil pump. It was a small piece and only put a scratch in the pump so we cleaned it up and put it back in. Spun fine and had no pressure loss from before runs between 30 and 60 psi.

We took the car out wednesday and ran about 15 laps before the water pump came loose. 79 block and threads were corroded. we helicoiled all of the holes and ran about 30 laps thursday night. Car ran strong for about 25 laps then began to fade. Found we had a broken lifter.

Got to the track saturday. No more than 4 laps in we broke another dist. gear. Oil pump turned fine. the dist. gear was ground down like sharks teeth. and then broke about 5 teeth. We changed auxiliary shaft and dist. gear. Barely made time in. The car wouldnt pull above 5800 (usually run closer to 6500. As soon as I pushed in clutch to enter pits it broke again <-- always breaks when i am slowig down.

Once again the oil pump is locked up. The dist. gears look fine other than where they are broke. they were not wore like sharks teeth anyways. Any ideas or help would be great. I feel I have a top 3 car if I could keep it together on raceday.

[car62]

change the auxiliary shaft bearings...they are wore out and putting the shaft into a bind.

[lester]

when you take the aux. shaft out check and make shore there is nothing in the oil hole had same problem

[dougskewl]

should I look into any aftermarket or modified parts when I fix it. I was told to leave parts stock so there is a weak link to save motor if oil pump has a problem but it seems as though the dist. gear is causing all the problems. I have heard of replacing the roll pin with a grade 8 bolt cut off. when the last one broke it sheared off the pin and shattered the gear rather than breaking any teeth.

[let-r-eat]

You should drill the pin to 3/16. Use a 3/16 roll pin. Check the oiling as described. Get rid of the heavy oils and don't quick rev the engine cold.

[dougskewl]

what weight should I be using? I have been running 5w-30

[dougskewl]

Can I run an aftermarket (bronze) distributor gear with the stock aux. shaft? They are so much easier to find

[dannyracer6]

I wouldnt, the stock cast shaft will eat up the b ronze gear. If you run the bronze gear, use the bullit shaft. It is more compatable. You can still break them if you free rev a cold motor or a thick oil engine. As for oil. there are a lot of synthetics out there as well as full on racing oil like Gibbs, royal purple, and brad pen. I ran 15w40 shell rotella. I have heard that valvoline vr1 syn 10/30 is great as well.

[dougskewl]

Pulled the motor down tonight and found a few other issues. 6 of the 8 lifters had the retainers come off. There was plenty of oil on cyl. Walls but nearly none on distributor gear. Aux. shaft does not seem to have any play and bearings look good. All of main and rod bearings had good oil and nearly no wear. I could not find any blockage anywhere in oiling system.
We are replacing the oil pump, pickup, distributor gear, cylinder rings(sick of waiting for moly rings to seal) and all of the lifters. I am still concearned about distributor gear oiling since I cannot figure why it has an issue.

[TM 44]

Breaking dist gears, tops coming off of lifters. Sounds like to much oil pressure. If you run a high volume oil pump, change to a stock oil pump. Seen this problem before with HV oil pumps.

[Dan32]

I wouldnt, the stock cast shaft will eat up the b ronze gear. If you run the bronze gear, use the bullit shaft. It is more compatable. You can still break them if you free rev a cold motor or a thick oil engine. As for oil. there are a lot of synthetics out there as well as full on racing oil like Gibbs, royal purple, and brad pen. I ran 15w40 shell rotella. I have heard that valvoline vr1 syn 10/30 is great as well.

rotella is an awful oil to use its not designed for high rpms it turns to bubbles oil pump sucks air motor goes boom!! dont run that stuff it is designed to turn 3000 rpms and has no sulfer in oil!!

[dannyracer6]

Dan, I got mine from a tractor impliment company and it had all the properties in it that the new stuff at wal mart does not. I have run it for two years without any problems.

[dougskewl]

Breaking dist gears, tops coming off of lifters. Sounds like to much oil pressure. If you run a high volume oil pump, change to a stock oil pump. Seen this problem before with HV oil pumps.

Oil pressure has never been over 60 on the gauge. Gauge is new because old one was a pos.

[dannyracer6]

Oil pressure and oil volume are two different things. You can have 80# of pressure pushing thick oil and it be too much pressure for the oil wt. You canhave a lot of volume and lower pressure as well. It is not about just pressure, itis about oil flow. Thinner oil will flow better by the bearings and in the small orifaces in the block. Thick will not do as well. You want easy flow. Thicker is not necessarily better. Many high vol oil pumps are too much. I found that using a turbo oil pump works just fine. If you are running a dry sump system which pushes a lot of oil, then a Hi volumn pump is the ticket.