Technical Distributor/oil pump shaft

Currently reading:
Technical Distributor/oil pump shaft

ralfa101

New member
Joined
Jul 30, 2022
Messages
5
Location
albany, ny
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!
1659182570015.png
 
OP
OP
R

ralfa101

New member
Joined
Jul 30, 2022
Messages
5
Location
albany, ny
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

Active member
Joined
Jul 2, 2022
Messages
302
Location
Torbay
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?
 
OP
OP
R

ralfa101

New member
Joined
Jul 30, 2022
Messages
5
Location
albany, ny
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.
 
OP
OP
R

ralfa101

New member
Joined
Jul 30, 2022
Messages
5
Location
albany, ny
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.
 

timmycm850

Active member
Joined
Feb 28, 2016
Messages
616
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

Active member
Joined
Feb 28, 2016
Messages
616
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

Active member
Joined
Feb 28, 2016
Messages
616
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.
 
OP
OP
R

ralfa101

New member
Joined
Jul 30, 2022
Messages
5
Location
albany, ny
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!
 

Attachments

  • IMG_4531.PNG
    IMG_4531.PNG
    1.1 MB · Views: 5

timmycm850

Active member
Joined
Feb 28, 2016
Messages
616
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

Active member
Joined
Jul 2, 2022
Messages
302
Location
Torbay
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?;)
 
Top