NoPistons -Mazda Rx7 & Rx8 Rotary Forum

NoPistons -Mazda Rx7 & Rx8 Rotary Forum (https://www.nopistons.com/)
-   Rotary Engine Building, Porting & Swaps (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/)
-   -   Fd Oil Presure? (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/fd-oil-presure-75931/)

Grizzly 11-09-2011 03:33 PM

Hi all.



Does anyone know if there is a trick to testing what pressure the Oil regulator is opening at?



I have an engine apart that is showing signs of bad oil pressure, even though this engine was built from new parts three years ago it has had a hard life (used for Track days etc) also i don't know if the Oil reg/Front bypass was new or second hand at the time?



So i have two options try and test the reg and see what pressure it opens at? or just replace it?



I think the Bypass isn't so hard to check, i'm told all i need to do is measure the length of the spring (of a matter of course i always check the piston of both reg and Bypass moves freely and seats well)



I have been toying with the idea of rigging the Reg upto the compressor and wind it up until it opens but is that an accurate way of testing it?

shainiac 11-11-2011 12:05 AM

What weight oil were you running? What were the signs or bad oil pressure? Just worn bearings?

Grizzly 11-11-2011 01:00 PM

Well it was using good quality 10-30 oil, when i say it was showing signs of bad oil pressure all the bearings (rotor/Stationary) are shot, the end float was excessive (not exactly sure why as i've not measured the thrust bearings etc) and there is metal fillings in the filter/oil as well.



The odd thing is this engine has been over maintained (has its oil changed every time it goes out, so never does more than 500miles on the oil) inside the engine is very clean (no cooked on oil etc) but the reason it was pulled was it had lost power and it was noticeably more noisy even though it didn't knock.



As i say there is nothing obvious, but the more i look at it the more damage i find to do with the oil system (just noticed the Oil pump and front plate are quite scored) i am starting to think one of the bypass valves may have stuck open causing low pressure?? But the guy who was using it said he never noticed any drop in pressure or warning lights for that matter, but this is the same guy who blew seized a motor a while back when his cooler line split and dropped all the oil and he kept racing until it seized (yep he gets well into his racing and has more money then sense, He wasn't popular that day i can tell you)

shainiac 11-11-2011 03:45 PM

It wouldn't be too difficult to machine a block of alum into a pressure tester. One metric thread for the rear regulator, one 1/8" for a pressure gauge, and one 3/8" for a standard air line fitting. drill the 3/8 and metric straight through and the 1/8 perpendicular. The reason I ask about the oil weight, FCs run 20w50 and every engine I've torn down has had reasonably good bearing surface, considering mileage and what not. I have seen a lot more FD bearings with more copper showing for even less mileage. And RX8s show premature bearing wear even worse with 5w20. I can't remember the OE recommended FD oil weight (5w30 sounds familiar), but I noticed a trend there. I know crank journal diameters changed throughout the variations of the 13b, so that very well could be why. Anyone else have any ideas?

Grizzly 11-12-2011 05:20 PM

I am 50/50 between just buying a brand new OE Rear Regulator or buying one of these http://www.pineappleracing.com/oilregulatortool.aspx the main reason i don't just buy a new reg is i hate not finding out why some thing has failed, i understand what your saying about the different oil but lots of people i know use the same oil (including my own fd) and not had this problem? so i'm thinking its a fault or maybe put together with the wrong size bearings?? duno?? Its a bit of a mistory.

Grizzly 11-17-2011 06:34 AM

Well i finally decided to just buy a brand new Rear Regulator, front spring and plunger, i figured if it was new it would be to spec.


All times are GMT -5. The time now is 02:58 PM.


© 2024 MH Sub I, LLC dba Internet Brands