Hi Andrew. 

I have used various weight oils. Not a huge difference.

Is your engine a Seres 1 or 2?

Do you have a log of oil pressures and temps to compare with mine.

I was under the impression that other rotaries increase in pressure substantially with rpm.

Steve

On 5 Nov 2024, at 8:48 am, Andrew Martin andrew@martinag.com.au <flyrotary@lancaironline.net> wrote:

Steve, why such a heavy weight oil? 

Maybe try a 5w30 mineral or semi syn oil.

Andrew

On Tue, 5 Nov 2024, 06:56 Stephen Izett stephen.izett@gmail.com, <flyrotary@lancaironline.net> wrote:

Thanks Doug. Yes, Racingbeat does have some helpful material.

My question is the ‘why’ the lowish oil pressure on RPM rise?

NOTE: I did have a very high rpm and therefore high pressure event on initial start years ago that may have damaged something in the oil system path.

I’m endeavouring to discover what this might be.

Recent and consistent data: (Renesis Series #1 4 Port with MT CS Prop - Oil Pressure reading tested within ~2psi, Oil is Synthetic 20W60, 44 Row Mocal Oil Cooler)

Lined Up Before TakeOff OAT 74F  60psi @ 2100rpm OilT 142F

Wide Open Throttle +10 seconds   65psi @ 7200rpm

+2 mins (WOT and CS Prop Set) 51psi @ 6400rpm OilT peaks 207F

So Oil Pressure only rises from 60 to 65psi after 2100->7200rpm (5100rpm increase)

Oil temp increase & viscosity decease has Oil Pressure then settle down to 51psi.

I think I have clarified in the last day that the Renesis series 1 front cover to front iron path uses a metal gasket ‘without' an o-ring.

This discounts the possibility of an o-ring failure causing oil to be dumped back into sump just after the pump.

It appears I was led astray by a schematic drawing that showed the RX8 series 1 oil system as having an o-ring seal in the front cover to iron path.

So, I am now investigating the likelihood of the following possible failure points and the work required before committing and jumping into getting dirty. 

1. Pump - Could the pump be damaged?

2. Front relief valve - Could the Spring break or otherwise be cracking at a much lower pressure?

3. Rear relief valve - Same as for 2. Above.

4. Thermal Pellet delete - Could I have messed this up or damaged the oil path when I replaced the OEM pellet with Tracy’s part.

My assumptions include:

1. The Mocal 44 Row Oil Cooler will have a lower pressure drop than the OEM cooler/s

2. Oil Pressure should rise to Rear Relief Valve Pressure + some, maybe 75psi  @ >6000rpm in a Series #1.

Appreciate further consideration as I try and figure this out.

Thanks

Steve 

On 4 Nov 2024, at 8:31 pm, DOUGLAS LOMHEIM dlomheim@aol.com <flyrotary@lancaironline.net> wrote:

Racing Beat has always provided good background info, and here’s a link to their discussion / products to increase oil pressure…

Rotary Tech Tips: Oil Cooling Tips racingbeat.com

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Doug

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