[RRToadHall]

I am trying to wrap my mind around an oil pump rebuild. I want to confirm my thought that the outter rotor is stationary in the front cover. Then that the drive gear and inner rotor work much like a wankle rotory. Can someone who has done an oil pump rebuild confirm this theory?

 

[shupack]

I've not done a rebuild on a RR oil pump, but a gear-type pump is common. It works more like a supercharger, than a rotary. both gears turn together, as the teeth un-mesh it creates a low pressure, sucking oil in. As they re-mesh it squeezes the oil out into the oil-line to the filter and onwards...

basically like this:

http://en.wikipedia.org/wiki/Gerotor

 

[RRToadHall]

I've seen lots of two gear pumps like that, however our pumps have three gears. I am making the assumption that the two inner gears act as the single gear in your link. I am just not sure if our outter gear is stationary or if it has a low tolerance rotation. RAVE does not give a inspection clearance if it has rotation. :think:

 

[TerryY]

If the timing cover wear surface around the outer gear was torn up by the pieces you may need to replace it too.

If not be sure to run a magnet thru all the oil passages on the cover to see if you can find any small pieces before they go thru the new pump.

 

[shupack]

3?, no, 2..

http://www.roverparts.com/Parts/8979.cfm

the inner piece is a gear-to-crank adaptor, the middle ring is the "inner" gear. It's a 2 gear pump, the outer gear rotates within the timing cover.

 

[nipper]

3?, no, 2..

http://www.roverparts.com/Parts/8979.cfm

the inner piece is a gear-to-crank adaptor, the middle ring is the "inner" gear. It's a 2 gear pump, the outer gear rotates within the timing cover.

Second that.

 

[nipper]

I should also have said that I had to replace mine because the outer ring was cracked. You could actually pull it apart and yet the engine was running OK as far as lubrication went and there was no exess wear anywhere in the engine.

 

[RRToadHall]

Here is the before and after. A spray of orange cleaner, a little emory cloth, a one heck of a lot of coffee. The pump turns freely and smothly yet is snug in it's cover. I just have to go get some thread lock and reassemble with jelly to prime it.

 

[nipper]

Here is the before and after. A spray of orange cleaner, a little emory cloth, a one heck of a lot of coffee. The pump turns freely and smothly yet is snug in it's cover. I just have to go get some thread lock and reassemble with jelly to prime it.

That type of pump doesn't need to be primed, it's self priming.

 

[joekinNJ]

If it makes you feel any better, I did a front cover replacement. While I was afraid to start it the first time, I removed the spark plug wires and turned the engine a few times to get oil into the engine. Wether or not it made a difference, it did work. I just had to change the oil to get rid of all the Vaseline.

 

[RRToadHall]

I've read both side of the prime or no prime discussions. The old fart in me has always primed so I did on this one as well. After 30 years of restoring and rebuilding cars some habits are just hard to break. :?

The great news is that with a great deal of slow plodding work, patience and 20+ fittings and rechecks, I was able to save the front cover. :thumb: The cheap side of me just wasn;t willing to buy a new front cover because of two little nicks.

 

[joekinNJ]

Found a vid of "the eccentric oil pump" http://www.youtube.com/watch?v=Oyo3FrPCq28