Mailing List flyrotary@lancaironline.net Message #67148
From: Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Oil Pressure
Date: Tue, 8 Feb 2022 10:02:23 -0500
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Surprised. I was expecting higher after what I had read.

Finn


On 2/8/2022 12:59 AM, Stephen Izett stephen.izett@gmail.com wrote:
Hi Finn

Did you mean to write - With the (4-port) Renesis I'm also surprised to see 70 psi or less?
Or did you mean “I’m also NOT surprised….”

Steve

On 8 Feb 2022, at 12:54 pm, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:

On 2/7/2022 9:00 PM, Charlie England ceengland7@gmail.com wrote:
On 2/7/2022 7:17 PM, Stephen Izett stephen.izett@gmail.com wrote:
More data on oil pressures going back in time

Hobbs  T Off     Lowest

27.4     69        48

34.9     69        48

36.9     70        46

46.3     65        48

59.8     66        49

67.7     68        47

70.6     65        35


So they look pretty consistent until the last flight.
I haven’t checked the sender.
I did do a rewire of sender wiring. I will check this however the pressure at Take off was within the range of previous temps (Lowest of the previous readings)

Can anyone comment on the reasons and their probability for lower oil pressure?
I believe the Renesis 4 port has only one oil pressure regulation valve. 

Cheers

Steve
<RX8-oil-engine-sys.jpeg>

On 8 Feb 2022, at 7:29 am, Stephen Izett stephen.izett@gmail.com <flyrotary@lancaironline.net> wrote:


Hi guys

I’ve just noticed that my oil pressure on the last flight dropped lower than ever before.

At takeoff 7000 rpm with an oil temp of 71C (160F) it peeks at 65 psi (according to the sender) then drops off as Oil temp peeked at 100C (212F) with a pressure of 35 psi.
During the flight as the oil temp dropped to 86C (187F) the oil pressure was then 55 psi.
Pressure appears independent of rpm and closely tracks oil temp.
I can’t recall the weight of the oil I’m presently using.
Engine is a standard unmodified Renesis 4 port except the mod to replace the thermal pellet in the e shaft.

Would appreciate your thoughts and numbers.

Steve Izett
IIRC, Tracy had similar symptoms when an O ring in the oil path into the accessory case failed. Can't recall if it was in the early 13B or the Renesis. It's been a long time, so my memory may be flaky. Should be something in the archives.

Charlie



That was early on withe his first 13B, not his Renesis. Described in detail in his conversion manual.
Actually I don't know if the Renesis has the same weakness at the front cover to engine block interface.

With the (4-port) Renesis I'm also surprised to see 70 psi or less after oil has warned up to 120F or more.
Highest I've seen in 80 psi and that is while oil is warming up after starting engine.
Seen as low as 35 (typically 40) near idle.
Definitely seems temperature related.
This is a stock (early?) 4-port Renesis.

I thought I had read that the Renesis ran much higher (100 psi) but that is not my experience. And I should have chosen a 100 psi pressure sensor instead of the 150 psi one I use.

Finn




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