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+--- Thread: Oil pressure... How much would be too much? (/showthread.php?tid=2733)
Oil pressure... How much would be too much? - 300D50 - 06-21-2011
Anyone know the safe upper limit on oil pressure with a 617?
What would blow first if she hit 200+ PSI?
I've heard rumors that it's not good to run too high a PSI on the mains and rods, but never any hard facts as to why, just the standard "it'll blow out seals".
I'm assuming the seals in the IP would be the first thing that would get ornery, but are there any other rubber seals in these engines that might be affected?
I'm asking because when I remade the back of the oil pump to relocate the pickup, I was unable to include the stock pressure relief valve in the new design.
This was in part because the old pickup/rear plate was cast aluminum and used some rather expensive non-standard tooling in its original manufacture.
I'm also having trouble finding an external adjustable regulator in my price range, hence asking what the max the engine can take is. My plan is to possibly run the pump without a regulator, and deal with the possibility of a 200PSI spike at WOT.
Assuming a quasi-linear relation of oil pressure to RPM, 100 PSI at 3K RPM would be ~ 180 PSI at 5400 RPM.
Right now I'm not worried about hoses or filters or the like, those can be dealt with when the time comes.
In case you don't know, engine is a 617.912 that's getting the rotating assembly and valvetrain from a 617.95x engine.
RE: Oil pressure... How much would be too much? - Captain America - 06-21-2011
There is no oil galley that you can add the regulator to?
What does the stocker look like?
RE: Oil pressure... How much would be too much? - 300D50 - 06-21-2011
The stock relief valve is a poppet type built into the pickup foot/rear of the oil pump.
I can tap into the gallery that feeds to the filter with ease, the thing is finding a nice adjustable external regulator.
I suppose I could just adapt the innards of the stock one into an external adjustable configuration.
RE: Oil pressure... How much would be too much? - Captain America - 06-21-2011
There isn't a way to adapt the stock regulator to the filter gallery so that everything stays internal?
RE: Oil pressure... How much would be too much? - 300D50 - 06-21-2011
The stock regulator is part of the cast back of the oil pump, so I'd have to remake it entirely.
It was setup to just bypass the excess oil directly to the inlet of the pump.
The only way I could make it internal would be to remake it and put it back onto the rear of the oil pump, but then I wouldn't be able to adjust it without removing the bottom sump.
The filter gallery exits the block to go to the filter housing anyways, so that's the easiest place to tap into it, especially since I've already completed the new rear pump housing.
I'm not really worried about where to put a relief valve, the main thing I;m looking for is what the effects of oil pressure being higher than stock would be.
I know I'll have a small hit in HP and a bit more strain on the chain/sprockets, but I'm unsure what will happen to the mains, rods, valve-train, etc... Like I said, all I've ever heard is "don't, seals will blow out", but no other reasons...
RE: Oil pressure... How much would be too much? - Biohazard - 06-21-2011
Last time I've heard of a problem from too much oil pressure, was a full race SBF that ran like 140+psi on the circle track. It actually spun a bearing if I remember correctly (about 15 years ago?). Do the front/rear main seals have to deal with full oil pressure or just residual/splash? I know there is pressurized oil to the IP, via external line (plastic), also the timing chain retaining nut/washer opposite of the IP has to seal against oil pressure. Cam doesn't have actual bearings, so thats fine. Rod and main bearings may not like it if it goes too high. Sadly the only way to find out sometimes ends up being expensive. Would the piston squirters handle increased pressure? Head gasket? Thats all I got for now. Hope it works out ok.
RE: Oil pressure... How much would be too much? - 300D50 - 06-21-2011
The squirters are just a small orifice with an anti-bleedback valve, sealed via a machined surface, so they should be good after some 515 or 518 is used.
The front and rear seals deal with splash only, no pressure.
No clue on the head gasket...
The spun bearings has me worried though...
RE: Oil pressure... How much would be too much? - dieselboy - 06-21-2011
Your turbo would blow the seals almost instantly.
I would also venture to say that you would fill the top end with oil being that the oil will flow out faster and in a greater quantity than it can return to the oil pan. Just a theory though.
RE: Oil pressure... How much would be too much? - 300D50 - 06-21-2011
Ah, that is something I was overlooking...
What flow rate in GPM does a KKK need usually? I can find needle valves in the proper range all day long to dial in the flow for the turbo.
The drain-back problem in the top end I didn't think of, but I don't see it being an issue, since the timing chain area in the front allows a full gallon of oil to pour in as fast as the jug will drain it.
Hmm...
RE: Oil pressure... How much would be too much? - Captain America - 06-21-2011
(06-21-2011, 07:56 PM)dieselboy Your turbo would blow the seals almost instantly.
How? There is a inline restrictor.
I dont remember the orifice size out of the stock oil fitting for my Garrett but its very small already!
RE: Oil pressure... How much would be too much? - led-panzer - 06-21-2011
Quote:How? There is a inline restrictor.
Whose size is probably based on stock oil pressure. Admittedly I'm no expert with these things but even though you have a restricter it still could push too much through with too much pressure.
RE: Oil pressure... How much would be too much? - yankneck696 - 06-22-2011
OK, time for a full billet oil pump with WIFI microprocessor adjustable pressure & volume...LOL
Ed
RE: Oil pressure... How much would be too much? - Captain America - 06-22-2011
(06-21-2011, 11:02 PM)led-panzerQuote:How? There is a inline restrictor.
Whose size is probably based on stock oil pressure. Admittedly I'm no expert with these things but even though you have a restricter it still could push too much through with too much pressure.
yeah, whats a 100 psi difference lol!
RE: Oil pressure... How much would be too much? - 300D50 - 06-23-2011
(06-22-2011, 05:08 AM)yankneck696 OK, time for a full billet oil pump with WIFI microprocessor adjustable pressure & volume...LOL
Ed
Funny you should say that, I was thinking of using a high duty cycle hydraulic valve and a feedback loop from a pressure sensor to control it.
Then I realized if my alternator crapped, I'd be in the same boat anyways...