R.P.M.

I have been reading some of the threads in the FAQ's, and have seen alot of stuff being written about the oil pump intstallation after rebuilding a motor. Like the kew fallin out and not lining up properly.



What is wrong with taking the 4 10mm bolts, that hold the pump onto the front iron, off and sliding the whole assembly (chain still attached to the sprocket on the e-shaft) off? Is the oil pump timed with the e-shaft? Is that why there are two little dots on the oil pump internals, do they have to be lined up properly with the key way on the e-shaft?



Sorry about all the questions, I am very experienced in taking rotaries apart, but I'm in the process of learning how to properly reassemble them.\



Thanks

Joe

Lynn E. Hanover

The method you offer is OK. There are no service parts in the pump. But it is a good idea to look inside to see if any materials have passed through it causing damage. The pieces are made using powdered metal foming, and are not very strong. So you may find a ring cracked or pieces of this or that pressed into the surface of a rotor.



The dots are so you can assemble the ring and rotor in the same relationship as original. There is no timing involved at all. You can still interchange the two rings, so as you inspect them do one at a time and wrap some masking tape around the parts to keep them together.

It won't matter much if you reverse a ring or swap them, but it is poor practice.



For long term high output, like over 100 PSI with the stock oiling system, Racing

Beat used to sell a heat treated gear set pump that seemed to hold up nicely. The stock pieces can (very rare) turn back into powdered metal when abused or ingesting stray contamination.



When I used stock style pumps (Racing Beat) I red locktite the key into the groove and clamped it in place for a few hours. I never hade a problem with the key sliding out on assembly.



The pump has other problems as well. The two sections are shaded (not in index) so as to make less noise, and work a bit better as two small pumps where one big pump should have been used. The front section must pull suction oil through the rear section and then force presurized oil back through the rear section. You know that mother nature and Mr. Burnulli hate sharp corners, now look at that divider plate between the two sections. Four sharp corners there and another complete set in the face of the cast iron where the pump mounts. The screen over the end of the pickup tube and the sharp end of the tube are flow disasters.



The third gen pump is bigger and has suction inlets on both ends. So Mazda knew the pumps sucked, and finally changed it.



But I run on as usual.



Lynn E. Hanover

banzaitoyota

Lynn, keep on running buddy.

setzep

Just a few days ago I cut off the screen on my oil pump pickup tube and now I'm looking for a way to put a slight flare on this metric tubing.

Lynn E. Hanover

Stop by the Tractor Supply company store and buy a real thick washer about 2 1/2" diameter. Bore the hole out to fit tight on the end of the pickup tube.



Press into place and braze the upper side all around. With a die grinder, radius the inlet end of the tube to include part of the washer, so it ends up looking like a trumpet bell.



Clean and install. Be sure none of the washer touches the oil pan.



Improves high RPM oil pressure sag. And reduces foaming.



Picture is of this mod. The bug screen and anti vortex bowl is from a Pontiac. The stock Mazda piece is too small.







Lynn E. Hanover

l8t apex

Lynn its great to read your application of R&D.

Thanks

setzep

Ahh, that's the picture I was looking for. I think you posted it a few months ago. So I should leave the screen off, right? I'd like to cut a o-ring grove in the pickup tube flange but it doesn't look like I have enough material to do so. Hmm... maybe if I use a smaller o-ring, maybe a 018-70 duro.



Thanks Lynn

Lynn E. Hanover

Note that it says thicker flange for the "O" ring mod. Not a big deal if you can get to a lathe. The bolt flange can also be made from a thick washer, or just any chunk of mild steel 3/8" or thicker. Space your piece off of a face plate, or just grab it any old way in a chuck. Once you start machining just don't move it. Bore the pickup hole. Cut the "O" ring groove. Make a fine face cut to get a good mating surface. Cut through the piece well outboard of the attach hole location.



If you plan on going into the weeds that far on oil system mods, then you would be thinking about more volume in the pan, A defoaming tray with no holes forward of 1/3, to keep oil from filling the front cover on hard braking, perhaps a flat bottom for the sump, if you want to retain a bug screen, add one from a large V-8 pickup. the added weight and natural sympathy for a lower RPM harmonic requires high quality bolts and safety wire.



If the iron is apart, you can slick up the suction side drillings to rid it of the sharp corners, and polish the runners. The pressure side runners suck real bad also.



No sharp corners ever. This requires a long shank carbide ball bit.



If I had to go back to an internal pump, I would eliminate the "O" ring junction at the front cover. That ring blowing out has cost thousands of engines, and even with a plastic backup ring on newer versions you can still blow it out. When you jack up the oil pressure it can flex the cover and take pressure off of that junction. Many folks put the cover on with no gasket, trying to get more pressure on that junction. Not likely to help much with .020" more crush, but every little bit helps.



For aircraft use I am thinking about a tapered steel sleeve pressed into one face after tapering the hole a bit. So that junction would be bridged by a tight fitting tube with no "O" ring at all. Or, how about a thick aluminum washer to fit into that well, with no "O" ring at all. Plenty of crush. You can use the gasket. Nothing to blow out.



But I run on again.



Lynn E. Hanover



The picture is of a poorly done pump land area. Needs more work, and should look like chrome.

GTUs

Lynn,

what is that lube notch for?

and the Land area mods, can you go into abit more detail?





thanks

setzep

Thanks for the great info! I think I'll wait to make my own pickup tube, flange, defoaming tray and oil gallery porting. Sounds like a good project when I have the engine apart. Right now I have a lot of other things that need to be done to the car to get it ready for spring. But I do find your front iron to front cover o-ring info interesting.. After I put the front cover on I figured I'd check to see how the o-ring and backup ring looked. I was shocked to see that the backup ring and o-ring wasn't pressed to the front cover firmly with a front cover gasket. To fix this I thought I would use a bit larger o-ring. If I take the gasket out won't my CAS be out of mesh with the e-shaft gear? I wish mazda didn't use a front cover gasket and instead just use a single o-ring with 25-30% crush. We would have never worried about blowing that o-ring out. At work I use 25-30% o-ring crush on some manifolds I machine out and I've never had a failure with over 30 times the pressure applied than any engine oil pressure would be.