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-   Rotary Engine Building, Porting & Swaps (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/)
-   -   strange oil pressure problem 13b REW (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/strange-oil-pressure-problem-13b-rew-75987/)

-stig- 12-08-2011 01:16 PM

Hello guys!



I'm pretty stuck on this one...



facts on the engine: new build, singelturbo, Streetport. old engine died due to the same problem. only thing that is re-used is: 1 rotor, 1 housing, front plate and the front cover. all bearings where changed, and front stat gear. new oilpump and regulator.



Problem is as follows:



on hot engine, i only get about 60psi @3000rpm, and it doesent get any higher at any rpm. this is measured at the oilfilter with a shop manometer ( the readings are the same after and before the filter) the pressure seems a bit bumpy, no smooth changes.

Idle @ 1100rpm and about 20psi pressure at the filter, and 60psi OUT of the engine at the frontcover.



when i measure at the pump outlet on the front cover i get easy 145psi @ 3500rpm and up, so the front regulator is doing its job.



So far i have tried a new set of coolers and lines, tried delete the whole cooler system but still then i only got a top pressure of 85psi.

i have changed the oilfilter.



i pulled the engine today and tested the rear regulator, came in about 110psi, dead on... the front regulator spring is at 71.2mm, 1.8mm shorter than stated in the manual, but i have much pressure out of the pump, so i cant see that to be the problem..

only thing i found was that the oil pickup where close to the bottom of the oilpan, it was in to the bottom i think by the looks of it, have not measured that.



Do ANYONE have any good ideas for me? pretty stuck here, its a shame to put it back in to the car and find the same fault again...



Thanks for your time, Stig

Grizzly 12-08-2011 07:03 PM

Check oil pump cover o ring is in good order (the correct one)



The Crank thermo pellet is not damaged (stuck open)



Make sure all the o rings are on the Dowls (if you are taking it apart)



Make sure you have the correct bolts in the oil pick up (easy to get them mixed up and they bottom out before tightening down 100%)



I know you have checked the Regulators but have you checked the Pistons are moving smoothly and fully seating (mainly the one in the front plate)



Then the more wild guess's...... Did you check the Plate for Cracks? (maybe you have a crack in a oil way?) Is the oil pump seated correctly? (i think it probably will be if you are seeing 145psi anywhere)

Grizzly 12-08-2011 07:09 PM

I have recently did a rebuild on an RX8 due to low oil pressure, that turned out to be a Cracked Stationary gear (which was a little odd and not seen it before) basically a good quantity of the oil was bypassing the crank which in turn killed the rotor bearings.

-stig- 12-08-2011 11:39 PM

thanks for the inputs guys!



O-ring in frontcover was ok!



thermo pellet is changed to a solid one.



the regulators have been checked, but i'll check them again! https://www.nopistons.com/forums/pub...IR#>/smile.png



cracks yes, that has crossed my mind... due to the problems have been following the engine, when so many parts have been changed its down to the front plate and cover..



thanks!!

Grizzly 12-09-2011 05:08 AM

Could the jet in the Crank be stuck open?(i presume its not been changed) I take it the Thermo pellet is the right way round? (if its possible to be the wrong way round??) also did you use new Stat gear/rotor gear bearings (if not did you check they where in spec??)



When you did the rebuild did you check the oil gallery's in the crank where clean?

-stig- 12-09-2011 05:19 AM

a new e-shaft was used in the last build, with all new bearings. had the stat bearings off today, and the where within limits and looked great.



i dont think the pellet can be mounted wrong, but it was in the way i always put them https://www.nopistons.com/forums/pub...IR#>/smile.png



have inspected the whole engine today, any cracks would cause an external leak, or leak under the front cover, but no cracks or evidence of this happening where found. cant find any reason to open up further a new build engine, so going back into the car with new oil sump and front cover.

CBarber 08-24-2013 02:41 AM

Re: strange oil pressure problem 13b REW
 
Stig,

It been a couple of years since this thread was posted. Did you ever find a smoking gun? I am having very similar symptoms. I have replaced and inspected dang near everything I can think of.

Thanks.


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