Technical Distributor/oil pump shaft

[ralfa101]

Hello. I just rebuild a 903 motor with 127 cam for my 600D. After minimal miles, the gear on the distributor/oil pump shaft wore down as below. Wear is even, and the cam gear looks fine. Why did this happen?

Thanks!

 

[ralfa101]

Hello. I just rebuild a 903 motor with 127 cam for my 600D. After minimal miles, the gear on the distributor/oil pump shaft wore down as below. Wear is even, and the cam gear looks fine. Why did this happen?

Thanks!
View attachment 410216

So it turns out I don't have a slinger on my Marelli distributor...no oil being slung could explain this??

 

[bugsymike]

I am certainly not a metallurgist, but photo does look like some oil has been getting there, is the oil pump drive recent also as it would make me wonder on whether the new cam and oil drive were compatible, plus the quality of the oil pump drive, as you say no sign of wear on that gear?
Did it whine from the start as though not happily meshed?

 

[ralfa101]

I am certainly not a metallurgist, but photo does look like some oil has been getting there, is the oil pump drive recent also as it would make me wonder on whether the new cam and oil drive were compatible, plus the quality of the oil pump drive, as you say no sign of wear on that gear?
Did it whine from the start as though not happily meshed?

Oil pump is recent, aftermarket. No appreciable whining. No wear at all on the cam gear. Thanks for the reply.

 

[bugsymike]

Oil pump is recent, aftermarket. No appreciable whining. No wear at all on the cam gear. Thanks for the reply.

Suspicion falls on quality of oil pump. No redress for engine damage?

 

[ralfa101]

Oil is being pumped elsewhere. Good pressure. I'm concerned oil isn't getting to the gears for some reason. Maybe a main bearing covering a passageway? I'll go look at the cam gear to see if oil is on it.

 

[RalphM]

Gear missed the hardening process.?

 

[timmycm850]

Let us see the cam gear. Is the oil gallery clear from the main cap 1 to cam bearing.

What did the oil pressure guage read.

Tim

 

[timmycm850]

when you assembled the engine. Did you test the rotation of the cam/ oil pump and drive gear and dissy. all assembled as one before fitting the timing chain.

Tim

 

[timmycm850]

Do you have one of those cam gears with the extra oil way for the lubricating of the gears

 

[timmycm850]

did you space the oil pump drive gear within the block to stop it going up and down in between the block and the oil pump casing.

 

[ralfa101]

With metal particles likely everywhere, I going to pull the motor, disassemble, and clean everything out...unless all the metal is in the centrifuge!

I just have an idiot light, no pressure gauge...this motor is in a 600D.

I did not try rotating before putting the timing chain on....next time I will!

I have ordered a modified cam bearing, again for next assembly.

I don't know what you mean about spacing the oil pump drive gear. Please explain. I neglected to place the slinger on the Marelli distributor shaft. Don't know if this would have allowed play.

The cam gear looks fine. See attached.

Thanks for any comments!

 

[timmycm850]

When you put the oil pump drive shaft into the block it shouldn't have much movement up and down. Sometimes thebrass Bush in your photo can wear giving too much clearance. If your 7 litre sump casting is too thick it can move the oil pump accross and force the centering of the bottom of the shaft to be offset. Due to the size of the two gears the wear will slwats be on the smaller one first.

With the timing gears/ chains its always the smaller gear that loses its teeth first causing the timing marks to wobble arround.



Tim

 

[bugsymike]

When you put the oil pump drive shaft into the block it shouldn't have much movement up and down. Sometimes thebrass Bush in your photo can wear giving too much clearance. If your 7 litre sump casting is too thick it can move the oil pump accross and force the centering of the bottom of the shaft to be offset. Due to the size of the two gears the wear will slwats be on the smaller one first.

With the timing gears/ chains its always the smaller gear that loses its teeth first causing the timing marks to wobble arround.



Tim

If everything else is good, I would question the quality of the "pattern" part. I assume no longer available from Fiat?