Distributor gear broke off!!!!!!

hcooperrn

Cadet
Joined
Sep 7, 2009
Messages
9
Re: Distributor gear broke off!!!!!!

The exact same thing happened to me yesterday! Same symptoms -- going along just fine, rebuilt Chevy 4.3l, engine stopped like I switched off the key, and backfired once. No oil pressure when cranking, so I got the tow of shame.

This forum has been great in keeping me from making some stupid mistakes, but I think I made this one back when I built my engine before finding these boards.

Here's what I'm guessing went wrong with mine -- I mixed the wrong auto parts with the boat distributor. I built my 4.3l like I would have built any street/strip small block. I found a non-balance shaft, roller-cam, vortec engine as by base, used the stock truck cam, and added a high-volume oil pump. I then used the stock '89 thunderbolt IV distributor.

My fear is that the excess pressure from the oil pump put too much pressure on the distributor gear, causing the shearing.

As far as what to do, I really don't have the money to get an original boat engine, but I can get a distributor drive gear that was made for the original truck engine, and I will replace the oil pump with a standard volume/pressure pump just to be safe. The gear itself drives the oil pump, so the distributor shaft should be safe.

As far as gear teeth pieces, most should have fallen into the oil pan. If not, start looking in the pickup screen, oil pump, cut open the oil filter, etc. When things went south in our race engines, we searched until we found the pieces, and then didn't find pieces, and replaced everything up to that point.

Not meaning to hijack by any means, just wondering if there are other potential causes. Deck height makes sense, except that my teeth are worn away perfectly even, indicating full engagement.
 

lilb

Seaman
Joined
Nov 28, 2009
Messages
59
Re: Distributor gear broke off!!!!!!

Got the motor all put back togeather and primed the new oil pump and added some gas and she fired rite up.:) So now hopefully it will stay togeather for me longer than 2 hrs.

It also seems to run alot better than it ever did. Im guessin that is because it has a new gear on the dist. Well now it's off to the water this weekend to finish breaking in the engine.
 
Top