signofinfinity

Well I just had my secondary relief valve partially fail. this utterly ditroyed my engine in just 50miles from the rebuild. My shop blames the plastic coating guys, since the front cover on my fd may have been warped.

anyways, the plunger was baddly scorged, scratched and mangled and i saw it being pulled out.



This cost me all bearings, oil pump, side seals, e shaft and rear iron.....



So i had in mind of eliminating the valve from that position, and have a relief valve set up under the oil filter housing. this gives me access to regulate the oil pressure, and also keep my original front face, but avoid the use of that valve.



I know i saw some one here produced a cnc product but i just cant find it.



Do you think its a good idea, and do you think that it would be a reliability mod?will it effect the saftey of my engine having the relieved oil back into the sump using the under oil filter housing passage? or can i use the rear turbo oil return drain(rear iron)? ps i am going single turbo.... so that drain for the rear turbo will just be blocked...



Thanks for reading and your time...







George

ArmyOfOne

Which secondary pressure relief valve are you talking about? The system has 3 I believe, the one under the front cover, the one in the oil cooler and the third is the oil pressure regulator. Was it disassembled and cleaned before assembly? I know that when I took mine apart it looked disgusting but it still worked fine. I just shimmed it with a 5mm spacer. Pressure never drops below 90psi at idle.



What was the oil pressure when the failure happened? It may have lost the front oil ring.



The system that is on the engine can be modified to meet your needs. Donīt add anything else that can lead to more failures later.

Lynn E. Hanover

Was the plunger assembly installed while some plastic coating was being done? I don't understand the plastic comment.



Anyway the "O" ring junction where oil leaves the front iron and enters the front cover has killed thousands of rotaries. The Japs won't admit that but then they won't admit the rape of Nanking either.



The front relief valve opens to prevent the "O" ring from poping out on cold startup. But the front cover is so flexable that if you try it a few times, you can pop out the "O" ring anyway.



Street racers jamb up the front reliefe pressure with washers, when they want more oil pressure from the installation of a higher value rear relief valve (100 to 115 PSI). So that makes it more likely that the "O" ring will pop out.



What to do? If you have to use the stock pump, and the engine is apart, I would put a thick steel disc in the "O" ring hole so as to block all oil from leaving the engine. Then drill out the end of the latteral Gallery that runs past the faulty opening in the front iron. Install a dash 10 by "O" ring boss fitting in the end of that gallery. Now there is no "O" ring to blow out. If you are shakey on the "O" ring boss deal take the fitting and front iron to a machine shop and have them bore the hole out and plane the surface flat with a 45 at the mouth of the hole for the "O" ring to seal against. This the same sealing method used in hydraulics and on dry sump pumps.



Or, you might make a steel or soft copper "O" that is thicker than the stock "O" ring and just use that. If it is steel it cannot pop out can it? (the "O" ring deformes badly) It is then a situation where part of the ring is clamped between the aluminum and the boss in the iron and cannot return to its stock location. The only cure is to remove the front cover and replace the "O" ring. A giant pain in the ***.



As a joke on the round eyes they added a plastic washer around the outside of the "O" ring to add preload to the boss area. None of this would be needed if they had added a stud nearby the boss location to account for the flexible front cover lifting off under high oil pressure.



Do not use a tapered pipe fitting. The boss in the iron is too small and will crack out when you tighten the fitting.



The valving in the oil cooler is a temperature operated diverter valve that allows cold oil to run through the cooler rather than through the cooling channels for rapid warmup. It also prevents a big pressure drop in the cooler. Actual (maximum) oil pressure is controlled by the relife valve at the bottom of the rear iron.



For operation below 8,000 RPM the stock relief valving is fine (around 80 PSI) for racing at 8,000 plus RPM then an early relife valve shimmed up to 95 to 100 PSI is enough. For all out road or rally where operation above 9,000 RPM for extended periods is planned, 110 from a stock turbo relief or 115 from a Racing Beat relief should be used. I use a dry sump system with the maximum oil pressure set at 100 PSI and no bearing problems.



There you go, problem solved.



Lynn E. Hanover

j9fd3s

gee that was easy...



unlike nanking, the 98ish and up engines have no front cover o ring, they use a flat metal gasket, and the new iron has no spot for the o ring. at least the gasket cant blow out....

signofinfinity

Well, the plunger war removed when the face was taken for powder coating...( that the plastic thing... my err... sorry



well the o ring is already modified. i found a scorched plunger, very badly scratched. it seems that some contamination made it to stick.



so as such the problem lies with the valve it self sticking down

setzep

I was able to find a nice quad ring to put in my front cover. They are less likely to blow out than a typical round o-ring.

Lynn E. Hanover

Are you talking about a square section "O" ring? Or, something else? Is there a hyperlink to a site?



Lynn E. Hanover

setzep

yeah, square section I guess. I got it from work. Maybe I'll have to take a pic of one.

Kim

Would the Rx-8 frontcover gasket solve this little problem. ?

I read somewhere that it has a copper liner in it or something

Kim

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