Here is a 'high volume' oil pump that fits '85 and older engines.



That gear isn't supposed to be in two pieces, is it?

Somehow I get the feeling this ain't quite right.

thats pretty!

https://www.nopistons.com/forums/pub...IR#>/smile.png

Here's a close-up shot. What could have caused this?



As you can see, the crystal structure in the metal has been smoothed due to wear, so this thing cracked in service and continued to protect the bearings from excessive wear.



All I can tell you is this oil pump came out of the R5 13B I'm in the process of porting to go into my REPU. The internals showed signs of neglected oil changes (as you can see as a discoloration on the oil pump flange in the first pic) so I took everything apart and cleaned it all really well (notice the exploded view all over my desktop lol). Lucky I saw the broken gear, 'cause I would have reused this pump in this engine. I wonder how well it would have worked with streetporting and higher than stock oil pressure? Kinda scary.

wow, never seen that. put another ring in it!

Where can I get another gear?

i have a spare 13B oil pump you can have...



from a 13B-REw

Isn't that ring fully supported around the outside? If it wasn't I'd say a lump of something hard passed through there.



The leverage even a small piece of metal would apply is pretty impressive.

i imagine all of the 17.5mm pump parts interchange?

The REW type wouldn't fit because it's larger (the bolt pattern is further apart).



Yeah, the gears have small indentations from crushing stuff while pumping oil. The previous engine rebuilder didn't clean things very well. There are even small dings and imperfections on the flange where pieces of dirt or whatever got sandwiched between the front plate and the oil pump. There was also a chunk of old gasket that got stuck between the front plate and stationary gear's oil hole. Good thing the hole in the gear is a smaller diameter than the hole in the plate, huh? Suprisingly, the bearing surfaces looked ok.



If I can find just the gear itself in good shape and at a good price, I'll get one.