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

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

Lynn, keep on running buddy. https://www.nopistons.com/forums/pub...IR#>/smile.png

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.

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

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

Thanks

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

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.

Lynn,

what is that lube notch for?

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





thanks

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.

While I had the engine out for a oil pan leak fix (turned out to be the damn oil level switch) I figured I would plug off the OMP gallery.

If you plan on doing this I would be very careful about shavings getting in the oil gallerys from drilling/tapping. I removed the front stationary gear for this reason then flushed it out with oil and compressed air.

It's pretty straightforward to do, simply drill and tap. This is a 1/16" SHPP (socket head pipe plug).



I figure I don't need a ~.070" orifice bleeding of oil that could be going to my front bearing if I'm not running a OMP.

Also, make sure the eshaft is verticle and do not rotate the engine with the stationary gear out.

Lots of good info as usual in a thread with posty by Lynn. Thanks.



On the front sidehousing to oil pump pick-up it would seem like if you dress both surfaces very flat and use hylomar you would have a better than stock seal to stop sucking in air instead of oil. Hylomar gets more solid w/ oil and heat- make sure don't get it gooped up inside the tube of course and locktite the bolts.



On the oil pump body to front side housing it would seem there is a lot of chance for leakage as there is a wider mounting base for surface inconsistancies and you have high oil pressure at the pump outlet. There is also enough material on the pump body to cut an O-ring groove into the mounting flange. Would this be of any benifit?



As for eliminating sharp edges and 90 deg turns it is really easy to drill out and tap the front side housing oil pump outlet galley where the factory plugged it and put a pipe to -AN fitting there to outlet to the oil cooler. Then plug the front housing oil cooler outlet.



As for front cover gasket, I thought it was pretty much a given to ditch the gasket and use only RTV to get maximum crush on the front cover to front housing oil passage- does this trick not work on the later engines?



I aslo saw that JHB Performance offered a service to dowel this front cover to housing junction so that the O-ring is captured. Very good idea!



For working the front side housing oil pump cavities I found a 1/8" shank carbide burr in a Dremel flex shaft works great. My handle fit inside the oil pump pickup. To really work the edges smooth here and on the oil pump outlet cavity to galley I used the 10" split mandrel in the die grinder (that I made to port my manifolds) and I cut the stiff backed 80 grit into strips at the edge so that when I work it in and out of the galley it really abrades the edge. Then switch out to finer grits and polish away at all the galleys.



As for the notch between the oil pump land pressure cavity to pump shaft that is to force highpressure oil into the oil pump bearing area. The front of the pump gets a flow through from the pressure side into the front cover cavity, but the rear flow is more limited as it would more easily leak out between pump inlet and outlet cavities at the mounting flange than go down into the pump shaft bearing cavity.





Now, we need to start a thread about the oil mods done for flow once the oil is re-introduced to the engine from the oil cooler! I just got done adding the rear e-shaft galley, and porting the e-shaft bearing inlet/outlets to aid flow to the rotor bearings/rotor cavities and a tapping the front housing for the loop line to ease oil flow to the front bearings.



Getting higher pressure is good, but I believe higher total flow can really help drop the oil temps as well.

Ive been looking at this as well, apart from blocking off the pressure bypass and using the drilling in the side of the front iron it may be possible to use a tapered reemer on the front cover and the iron and use a brass compression fitting similar to the one pictured instead of an oring.

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also regarding the phasing of the two stages of the oil pump is it possible to modify the pump so it will be more efficient

For the land area mods, I cut the back off of an old pump. Then I can rotate the guts across the upper web and mark off the shape of the cavity formed by the ring and rotor as it captures a slug of oil and moves it to the pressure side of the pump to be squeezed out. Note that once the shape has captured the oil it moves through a few degrees of rotation before the volume is exposed to the pressure cavity.



I ink up the land with a Magic marker and scribe a thin line around the inside of the capture cavity. I then grind in from each side to within a few thousandths of the scribed lines. Keep checking with the cut up pump body to be sure there are a few degrees of rotation left where the high and low pressure sides are still separated. The mission is to remove sharp edges and to do so in an area that will not intrude into the capture volume. If you do make a mistake it will ruin the iron because the pump will not longer work. You can keep it around for a dry sump engine you should have built in the first place.



The notch into the bearing area from the pressure side is to aid in lubricating the rear end of the pump shaft. It is highly loaded and there is no bearing to protect the shaft. It is poor design to have no bearing material running on the shaft.



The reduction in the size of the land area between high pressure and suction will reduce idle and just off idle oil pressure. The width of the land acts as a seal to reduce bleed back to the suction side. Reducing the land increases the bleed back.

Lower oil pressure at idle just is not a factor because there is no load at idle. Any amount of oil is fine. Once the revs spool up the time available for leak back is reduced and it is no longer a factor.



A bit smaller version can be done on the bottom land also but it is much less productive. The job done in the picture is poor because the material removed changed the pump timing as is OK, but it did so at a steep angle that still makes for poor flow. A rounding of the sharp edge of the land is the desired result. Not a massive removal of material. Less is more.



You cannot get oil passages too smooth. Like chrome would be the best. No sharp edges anywhere, ever. there is no point at all to this modification if you are not running 100+ pounds of pressure, and larger bearing clearances.



Poor pump performance as a result of shading, sharp corners, poor pump timing and suction side design faults, tend to cost oil pressure and induce foaming at the end of a long high RPM pull with hot oil (not over 180 please). If you are not having the problem, leave it alone.



Most people are complete after of one or two gears woth of mind numbing accelleration. A racer has to have great pump performance after 45 minutes of mind numbing accelleration in all of the gears and wild eyed high performance braking.



Otherwise the stock system is fine. The pump will be more productive at high speed. Better flow results in higher pressure (assuming a high pressure relief valve is installed). If you premix, you could run the oil straight out the gallery with an "O" ring boss to AN 12 fitting, and block off the "O" ring junction in the front cover with a thick aluminum disc. Just one of many fixes you can do.



When helping the airplane engine guys I suggested puting the pump rotors into index and rounding the corners of the divider plate. Another idea was to remove that divider and shorten another rotor and ring, and make the whole length of the pump into a pump. Seems obvious.



The best answer is to hang a big nasty American V-8 dry sump pump on the side of the engine and forget that little bitty stock pump.



Lynn E. Hanover