Mailing List flyrotary@lancaironline.net Message #44409
From: Tracy Crook <tracy@rotaryaviation.com>
Sender: <rwstracy@gmail.com>
Subject: Re: [FlyRotary] Re: New Engine Break In with Gearbox -- for Tracy
Date: Thu, 4 Dec 2008 09:55:22 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
I see no cause for alarm on temps.  The oil pressure is questionable.  If the cause is restriction of filter or cooler I would be concerned.  I measure oil pressure at the engine and get  87 PSI when in regulation.  Only question is what pressure regulator Bruce installed in my hand-built Renesis.  I think it is stock 4 port RX-8.  My old 2nd gen engine did have pressure measured at remote oil filter and I did not see any sign of higher oil pressure due to restriction.  It was always 70 PSI when in regulation which is what the regulator was speced at.

Tracy


On Wed, Dec 3, 2008 at 9:20 PM, Bobby J. Hughes <bhughes@qnsi.net> wrote:
Tracy,
 
With the Advanced EFIS / engine monitor all of the instruments are factory calibrated and so far have been correct. Oil pressure is being read directly out of the engine before the oil filter and oil / water exchanger. I made a quick run to the airport this afternoon and made another 15 minute ground with the inlet ducts blocked. I was able to get the water up to 200F and climbing and oil to 165F. OAT was 75F Oil pressure varied from 65 at idle to 105 psi at 6000 rpm. On earlier ground runs to 7500 rpm I was only able to get the oil to 144F and water to 177F. OAT was 65F or less. and oil pressure in the 110-120 range. Warming the oil up did seem to make a difference.
 
Ed,
 
"Bobby, depending of where your oil pressure sensor is located (before or after the oil cooler – assuming a stock Rx-7 oil cooler with internal thermostat).   IF you have removed the thermostat in the oil cooler and have not blocked that thermostat opening, then a lot of the oil will not flow through the several passages through the cooler core.  This could mean you are not getting the normal pressure drop across the oil cooler which if your sensor is down stream would mean higher pressure at the sensor – but probably not more than 5 – 10 psi."  
 
No thermostat in the oil or water circuits. If the sensor placement is making a 10 psi difference then the problem may not exist. My remote oil filter adapter has two inlets and two outlets. I am using the second inlet for oil pressure and the second outlet will be used to monitor the before oil cooler temp with the EM3. No room at the engine oil pad adapter block for the pressure sender so this location was easy. It's visible in one of the photos.
 
Bobby
 


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Wednesday, December 03, 2008 11:31 AM

To: Rotary motors in aircraft
Subject: [FlyRotary] Re: New Engine Break In with Gearbox -- for Tracy

Odd problems.  Peak Oil pressure should not be significantly affected by temperature or oil weight.    What is it?  Lower viscosity oil is not a solution.  Are you sure the instruments are right / calibrated?

Tracy


On Wed, Dec 3, 2008 at 11:04 AM, Bobby J. Hughes <bhughes@qnsi.net> wrote:
I am having a problem getting my oil temps up and oil pressure down without an oil thermostat. Will try blocking some of the air flow this weekend. Is 10W-40 or 10W-30 to light for the gearbox during the winter months?  I plan to run the engine for at least 20 hours on the ground and switch back to Mobil 1 for first flight.
 
Bobby


From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Wednesday, December 03, 2008 9:12 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: New Engine Break In with Gearbox -- for Tracy

Next best in mineral oil is Shell Rotella.  15W - 50 or similar.

Tracy

On Wed, Dec 3, 2008 at 9:18 AM, Bobby J. Hughes <bhughes@qnsi.net> wrote:
Tracy,
 
What oil do you recommend for breaking in a new engine that is also acceptable for the gearbox? Bruce T said to replace the Mobile 1 for 10-15 hours so the apex seals will seat.
 
Thanks,
Bobby J Hughes
 
 



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