Mailing List flyrotary@lancaironline.net Message #62772
From: <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Oil Regulator bypass Flow Rates
Date: Fri, 2 Sep 2016 18:17:25 -0400
To: <flyrotary@lancaironline.net>
The calculation is actually fairly simple. Divide the engine weight in ounces by your hat size, then multiply by
your street address.  Convert that number to Cubic Centimeters and have a friend from Canada look up the answer.
 
Or, the amount of oil dumped by the regulator varies with RPM, oil pour weight, oil temperature, oil pump displacement, regulator spring pressure, suction lift distance, pickup tube end shape, and the shape of the  and the area and hole size of the bug screen selected. Oil pump performance is more affected by features in the suction side than the pressure side. 
 
Early regulators can be disassembled cleaned and have small washers added under the spring so as to adjust the cracking pressure to whatever you want. You oil it up and put shop air pressure in it. Adjust shop air upward to find the new cracking pressure. It makes a mess and you need eye protection. The twin turbo relief pressure is 110 pounds. Early ones were 73.9 pounds. Actually test the one you are about to install.
If you do not know the cracking pressure you cannot make valid judgements as to oil system performance or trouble shooting.
 
Mistral said 16 GPM from a test stand at 6000 (engine RPM).  Mistral removed the stock oil pickup tube and made up a nice aluminum tapered piece (looked like a horn). No bug screen. Defoaming plate had a big screen in the center to catch debris.
 
If you have been running a bit hot say 210 degrees. And your usual oil pressure is 85 pounds but you notice the pressure is now 80 PSI. Power back a bit and some pressure comes back. Good news. Under hard use throttle position just about drives oil pressure through a temperature increase. So if you run it hard and oil pressure drops below cracking pressure, what has most likely happened? The relief valve is no longer controlling oil pressure. The relief valve is closed. So, it matters not at all what cracking pressure you wanted. Temperature can make the pump less efficient. (Bleeds off pressure from the high side to the low side). Cracking pressure only limits top pressure and has no other function. Work on the suction side to improve performance.  
 
High oil pressure is used to move overheated oil out of the wedge quickly.
 
Oils are built for differing functions. I use RedLine 40 weight racing oil. Not one oil related failure since 1980.
Shifting between 9,400 RPM and 9,600 RPM. About 250 HP These engines use an external oil pump and hold 100 PSI under all conditions.
We raced for years on 75 PSI oil pressure.  You will see a reduction in pressure as oil temps goes up.
At first the reduction will be from some oil foaming that makes the pump a bit less efficient. Then the foaming plus thinner oil from temps.  
 
Build a spacer that looks like the pan gasket about 3/8" thick. No drainback problems.
 
Lynn E. Hanover
 
In a message dated 9/2/2016 1:40:36 P.M. Eastern Daylight Time, flyrotary@lancaironline.net writes:

James,

 

That’s the idea but the relief only needs to cover(uncover?) the midsection of the center iron and rotor housings. The oil drain back is still through the (7 or 8) 7/8” holes in the plate. Ed used rectangular tube to stand the oil tank off the plate so the oil pan bolts could be accessed externally. My plate extends below the engine and forms the inner wall for the oil tank. Mounting screws are access through the top removal cover.  Photo attached but the plate is covered up.

 

 

Bobby

 

 

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Friday, September 02, 2016 11:45 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Oil Regulator bypass Flow Rates

 

How about something like this Bobby?  The challenge would be figuring out how to do the oil pan bolts along the downward  (intake/exhaust) side of the engine.  You would need long bolts and some kind of standoffs internally to take the boltup forces.  Oil pickup would be internal.

 

— James

 

Not to scale, correct oil pan shape or bolt pattern!

 

cid:image001.png@01D20516.1876E470

 

 

On Sep 2, 2016, at 7:06 AM, Bobby J. Hughes <flyrotary@lancaironline.net> wrote:

 

I’m fabricating a plugs up oil pan and block off plate for my spare Renesis and new turbo FWF. I’m using Ed’s pictures as a general guide for fabrication.  I’m a little concerned about the oil drain back path  and volume. The path from the center iron and rear iron \ regulator would make most of the oil flow toward the front iron and down past the oil pump as the bottom of the rotor housings and center iron are flush with the block off plate. I will incorporate a recess in the block off plate to provide a more direct drain path over the rotor housings and center iron humps. The block off plate to external oil tank drain has (7)  7/8” holes. I’m hoping that’s enough to keep oil from backing up into the oil pump chain and engine cavity. I am considering using an external oil pressure regulator installed at a remote oil filter with bypassed oil feeding directly back to the tank.  I know the 13B oil pumps flow about 15-16 gpm but I have not located any information regarding how much is bypassed by the regulator.  Any ideas?

 

Bobby J. Hughes

RV10 Renesis  Super Charged 

300 Hrs

<Ed Anderson Plugs Up.jpg><IMG_2957.JPG>--
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