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Railcarmover · 09-16-2019, 07:55 AM

I did a bunch of investigating on mine without finding a root cause,cam bores measured out good,tappet bores measure out good,gear backlash spot on in four positions.No tooth wear that would indicate a 'heel or toe' condition that would indicate misalignment of the crank/cam..I realize that isn't a true indicator of misalignment,which if it did exist I'm going to run anyway.
Inspected oil pump,I polished the lower plate during rebuild,no wear on it currently,shaft straight,no apparent side loading.Cam drive gears good,no lifting when spun no load..I couldn't put a finger on the issue,my thrust from valve load was a theory,not a conclusion,which is why I put 'I figure' in the statement.

Imagine it would take a large offset of cam or tappet bores to force a 35 pound spring.Ford did use a fiber gear to lessen noise.

That is one possibility,the oil pressure..there doesn't appear to be any modification to raise pressure,but I didn't investigate based on that assumption..given the previous owner ran a 'pressure' line to center main and an additional crankcase vent at the back of the valve cover that does bear investigation..Ill be taking the engine back out soon,that will be checked..

converting the spring loaded plunger to a thrust button cured the symptom.I don't believe it bears that much greater of a load than the spring.with the engine idling I can turn the thrust screw by hand,once again not precise,but I was concerned how much force is being applied to the thrust button.

09-16-2019, 07:55 AM	#5
Railcarmover BANNED Join Date: Apr 2017 Location: Sacramento Posts: 1,262	Re: Timing gear/cam noise? I did a bunch of investigating on mine without finding a root cause,cam bores measured out good,tappet bores measure out good,gear backlash spot on in four positions.No tooth wear that would indicate a 'heel or toe' condition that would indicate misalignment of the crank/cam..I realize that isn't a true indicator of misalignment,which if it did exist I'm going to run anyway. Inspected oil pump,I polished the lower plate during rebuild,no wear on it currently,shaft straight,no apparent side loading.Cam drive gears good,no lifting when spun no load..I couldn't put a finger on the issue,my thrust from valve load was a theory,not a conclusion,which is why I put 'I figure' in the statement. Imagine it would take a large offset of cam or tappet bores to force a 35 pound spring.Ford did use a fiber gear to lessen noise. That is one possibility,the oil pressure..there doesn't appear to be any modification to raise pressure,but I didn't investigate based on that assumption..given the previous owner ran a 'pressure' line to center main and an additional crankcase vent at the back of the valve cover that does bear investigation..Ill be taking the engine back out soon,that will be checked.. converting the spring loaded plunger to a thrust button cured the symptom.I don't believe it bears that much greater of a load than the spring.with the engine idling I can turn the thrust screw by hand,once again not precise,but I was concerned how much force is being applied to the thrust button.