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Discussion Starter #1
Distributor gear failure – oil pump – guidance – watch outs?

My distributor gear chewed up approx. 100 hrs. after installing a new flat tappet cam. Cam change was from a mild Crane 204/216 to a *Cam Research 216/220 @ .50 lift. Only the cam was changed, engine had 20K miles. The oil pump is NOT a high flow type. New cam lost some teeth. Dropped the oil pan for a good clean up, - ready to reassemble with a new Crane 216/228.

ANY WORDS OF WISDOM? THINGS TO CHECK BEFORE REASSEMBLY?

I haven't found any cause for this failure. My machinist says oil pumps are usually responsible, calling this a “classic Ford failure”. I’ll disassemble & inspect the pump, hopefully reuse w/ a new drive shaft.

WHAT ELSE TO DO or CHECK? ANYBODY LOST A DIZZY GEAR W/ NO OBVIOUS CAUSE?

One last question - is .035” max. distributor end play OK? (Tom Monroe’s book and my machinist both say it is OK). I think Pat favors .008 to .010” why Pat?

Thanks, Ken

* for anyone interested, the 216/220 cam noticeably improved torque above 3000 rpm, lower end still very strong which is why the “new” new cam is 216/228 - still mild by VMF standards. Mine is driven daily and so many VMFers seem to have race cars. The average guy might wonder if the cam change was worth it in the seat of the pants feel, and at least prior to my very humbling coast to a stop on I-85, the answer was YES.
 

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Was drive gear on dizy same material as Cam?
Cast Cam - Cast Dizy Gear :)
Steel Cam - Cast Dizy Gear :(
Steel Cam Steel Dizy Gear :)
 

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It's fairly common for ford oil pumps of that design to lock up when any grit or small pieces of junk get in it. Most of the time, they just snap the distributor drive shaft, but I have seen them do the type of damage you described.
Their is also the issue of disimlar metals between cam and dis. gear, you might want to verify that.
Also, some people recommend changing dis. gears every time you put in a new cam when the old gear has more than 100,000 miles on it. The gears, like everything else, wear to match the cam, and it is possible that it could have prematurely worn the new cam.
 

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Discussion Starter #4
I had an iron dizzy gear & iron cam.

I think you're right about grit in the pump. Now that I can clearly see the cam bearings from underneath, there is heavy wear. The first cam required pulling to extract - a hint that the bearings were worn (after only 20,000 miles). Some metal grit came from there. Guess I need new cam bearings. It's like going back to square zero!

Anyone with a solid running engine remember this when you feel like you have to "improve" it with a cam change!
 

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Yeah, it doesn't take long after the cam bearings start going to start seeing problems. It will be good to have it torn down and all of the passages cleaned to get the remaining particles out. I know where you're at on working on a perfectly good running engine :)
 

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Discussion Starter #6
I told my machinist friend that my cam with only 25,000 mi. had to be pulled out, which couldn't have been good for bearings. He says "Yeah, Fords do that" - he sees hundreds of 'em. Tom Monroe's book says cam bearings can last 3 rebuilds, hmmmmm.

My machinist also said dizzy gear failure is very common - & had 2 other broken ones come in that same day! So they just fix 'em and fix 'em again. Some business!

I was a Chevy guy until this Mustang was given to me. Still, I'm anxious to fire it up with the new even bigger cam. May as well re-ring while the crank is out for new cam bearings. OK, no more whining.
 

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Yeah, I don't really know why they have such problems with the cam bearings. They are of decent size and have a good oiling system, oh well. If our customers can afford it, I like to have them replaced if apart after 50,000, or less if they look bad. For what little it costs it's extra insurance. As far as 3 rebuilds? Hooey!!!
We do probably an average of 1 Windsor a week, and I really haven't seen too many problems with the gears. We may be just lucky I guess. Most of the time the stock shaft will round off or twist off before too much major damage happens. One thing that does scare me though, is the aftermarket sump screens. The one I got for my Milodon pan for my 347 has huge holes in it, slightly larger than most aftermarket pick-ups. I'm gonna be in big trouble if anything ever does come loose, because anything that could get through it will tare up anything that gets in its way.
 
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