View Full Version : Oil system mods. Oil jets and pressure regulators
AHarada
04-19-2008, 04:34 PM
I am looking at different mods while my engine is apart. I'm interested in the mod that replaces the check ball and spring in the eccentric shaft oil jets with the weber jets. Now I know this may reduce overall oil pressure at idle/lower RPMs.
So what if I used a higher pressure rear oil pressure regulator and shim the front? Would this alleviate any oil pressure issues caused by the oil jet mod? The oil pressure regulator I am looking at specifically is one of these:
http://www.mazdatrix.com/boil3.htm
105-115 psi.
Does anyone know what the stock FD OPR's keep the oil pressure at?
Now they say they are for 74-92 engines, but I don't see why they can't be used REW motors.
I am also considering the OPR mod from this link:
http://www.rebuildingrotaryengines.com/videos/Oil_Pressure_Increase_With_Rear_Oil_Regulator
instead of using that regulator.
And does anyone know how much I would need to shim the front OPR and what parts to use?
AHarada
04-19-2008, 04:40 PM
Edit: The video states they measured the stock FD regulator at 68 psi, and the modified (crushed top) one at 88 psi. They also state they shim the front OPR by 1/8".
cewrx7r1
04-19-2008, 11:12 PM
The stock FD oil system makes over 68psi pressure. It all depends at what rpms you do the tests. In fact it normally will make over 90psi above 4000 rpm.
I did some easy mechanical common sense mods to my oil system to improve oil flow.
This mainly was cleaning up and slightly reshaping the oil pump cavities in the front housing where the pump sits and where the oil comes out. Then I matched up the oil input holes in the stat gears to the oil passages in the rear and front housings.
This along with the PineApple e-shaft washer mod, new rear regulator, new pump, and shimmed front regualtor, my pressure runs about 110psi with the racing oil jets.
I have friends who used the stock oil jets with the ball and spring removed, and their pressure is OK, but not as good as mine.
AHarada
04-20-2008, 02:56 PM
Could you elaborate on the "PineApple e-shaft washer mod"
So you're using a stock FD rear regulator with a shimmed front regulator?
cewrx7r1
04-21-2008, 02:58 PM
Could you elaborate on the "PineApple e-shaft washer mod"
So you're using a stock FD rear regulator with a shimmed front regulator?
http://www.rebuildingrotaryengines.com/videos/Eccentric_Shaft_Thermal_Bypass_Valve_Modification
cewrx7r1
04-21-2008, 03:20 PM
If you view the video, they use air pressure to measure the regulator pressure.
Oil being thicker than air, would give a higher pressure!
Signal 2
04-21-2008, 05:04 PM
Any risk to the rear seal (where I'm thinking pressure would be highest) with these mods?
cewrx7r1
04-21-2008, 07:00 PM
Both stat gears only have high oil pressure on the bearings. Then the oil leaks out into a large low pressure area to drain. Have you had a chance to looked at the parts and think about how it works?
Signal 2
04-21-2008, 08:07 PM
A few weeks ago I re-assembled my engine during the course of my first rebuild. But not necessarily thinking in terms of high and low oil pressure areas. Maybe next time. But thanks.
Barry Bordes
04-22-2008, 10:55 AM
One of the things I do is to bellmouth the oil pick-up and reinstall the screen.
It is a little hard to see in this picture.
Barry
http://i287.photobucket.com/albums/ll129/bbordes/oilpumppick-upbellmouth.jpg
Barry Bordes
04-22-2008, 11:06 AM
This mainly was cleaning up and slightly reshaping the oil pump cavities in the front housing where the pump sits and where the oil comes out. Then I matched up the oil input holes in the stat gears to the oil passages in the rear and front housings.
Like Chuck, I port the oil passages on the pump base and main bearing caps. I also use a little Loctite 515 gasket eliminator on the passage innerface of stat gear to housing.
http://i287.photobucket.com/albums/ll129/bbordes/125-2505_IMG.jpg
AHarada
04-22-2008, 09:28 PM
Do you have any pix of how you port the "main bearing caps"?
And what exactly are the main bearing caps? Isn't that a piston motor part? haha
cewrx7r1
04-23-2008, 11:22 PM
Do you have any pix of how you port the "main bearing caps"?
And what exactly are the main bearing caps? Isn't that a piston motor part? haha
When you take out the stat gears, you will notice that the oil holes do not match up with passages in the housing. This is evident by the staining around the holes. This is where you can chamfer them to reduce turbulance.
Some people have actually drilled out the complete passage from housing to stat gear to make them larger. But I think this was on a very race prepared engine. As is done to enlarge the e-shaft passages.
Barry Bordes
05-01-2008, 10:26 AM
The pump itself leaks at its parting surface.
I do a Judge Ito mod by making the thinnest possible gasket saturated with Loctite 515.
Incidentally this gives the pump an extra .0015” clearance so the next step is lap the housing back to the original dimension.
I also lap all the gears and the separator plate.
Barry
http://i287.photobucket.com/albums/ll129/bbordes/124-2464_IMG.jpg
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