Cam/Distributor Gears Revisited

[Anonymous]

I had a new cam and distributor gears go south about 800 miles into the brake in. Crane replaced tha cam and I reinstalled it with a new gear on the distributor. About 100 miles into the rest of my break in the distributor gear is about 1/2 way worn through. I haven't looked at the cam yet but I'm assuming it's in the same condition. Any Ideas on what is causing this?

 

[alloydave]

Hey there Rocky ,what type of motor are you running ? I have a 250 crossflow alloyhead and had my distributor drive gear chew out in less than 200 km . I had my cam and drive replaced .As to the cause of this ,there could be a few .My reco guy said that my camshft thrust plate was quite worn when we stripped the engine which would of given it to much endfloat ,which would put a lot of load on the gear .Secondly he told me my distributor didnt have enough up and down movement .Mine was quite tight and should have had a few thou clearance ,again putting to much pressure on the gear.I also run a high volume oil pump which according to Crow Cams puts to much load on the gear again .I know its a PITA but doing a bearing blue check on the gear and drive to check mesh is quite important on these types of engines as its seems to be an inherent problem .So inherent is the problem i was at the local speedway last night and a falcon was slowly going back through the feild getting slower and the commentator said "I bet that dissy drive is as sharp as a knife buy now" .I had to laugh when i heard that although a stopped laughing when i remembered how much time and money it cost to fix ,and that was after allready doin a full rebuild.
hope you sort out the probs.

cheers dave

 

[Anonymous]

Ya I guess that would be helpful. It's a 81 200 i6

 

[xctasy]

I've been busy designing a shaft uprade for my 200 engine. There must be 40 to 60 thou of up and down movement in the distributor drive. Our Aussie fords have a ~ 490 thou bronze bush which can get worn out to 480 thou easy as. The drive then can flap about in a wobbling luna orbit for years, slowly allowing additional rubbing over the dissy gears, munching things.

No-one lubricates distrubtor drives, so they chop out first, then the gear, normally. After many years, normally.



Any distrubtor work must ensure the up and down movement is 40 to 60 thou, period.


Second, aftermarket shaft gears are able to be updated, but they are an Aussie invention, and are cross-flow.

Meantime, Dave sounds like hes on to it.