Oil Pressure Relief Valve

Discussion in 'Norton Commando Classic Motorcycles' started by olympus, May 14, 2018.

  1. olympus

    olympus

    Joined:
    Aug 5, 2017
    Hi all
    Manual Sates relief valve lifts at around 45/55psi.... I read with interest on RGM site that they sell a version with 60psi relief.... apart from the extra horses being used, what are the general thoughts (Good & Bad please) on using this unit over OE?
     
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  2. Nater_Potater

    Nater_Potater

    Joined:
    Apr 7, 2013
    While far from being an expert here, experience with water cooled iron engines shows that increasing the pump's output beyond what leaks past the bearings only adds heat to the oil, in addition to your noted horsepower loss. Back in the day, everybody was installing high-volume pumps on their "performance" engines, when, in fact, they hadn't done anything to justify the increased volume. 'Does no good...

    As many people here have noted, these engines can go quite a ways without oil before things start to come apart. As long as there's oil getting to the crank and rocker arms, you're good to go.

    Nathan
     
  3. gtiller

    gtiller VIP MEMBER

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    Nov 5, 2012

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  4. MexicoMike

    MexicoMike

    Joined:
    Jan 31, 2010
    The "standard" for at least the past 75 years has been 10 PSI per 1000 RPM. SO...figuring 7000 RPM as max for a Commando, one should see 70 PSI at that figure. If you are only turning 6K, 60 PSI at 6k would be fine. At idle, 10-15 PSI is plenty.
     
  5. Triton Thrasher

    Triton Thrasher

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    Feb 10, 2009
  6. tonybsa

    tonybsa

    Joined:
    Jul 23, 2017
    There are,many different grades of stainless steel,some of them even rust.As a former regular customers of SRMs,I am sure they are made correctly.
     
  7. Triton Thrasher

    Triton Thrasher

    Joined:
    Feb 10, 2009
    Are you sure, or do you just happen to like SRM?
     
  8. kommando

    kommando

    Joined:
    May 7, 2005
    There have been reports of galling on the SRM stainless plunger in BSA A65's after only a few miles, Amals don't work for very long when the slide material is the same as the body for the same reason.

    With the valve set to 60 psi it does not flow more oil as that's set by the pump, it just diverts to the dump side later.
     
  9. toppy

    toppy

    Joined:
    Dec 2, 2012
    I ordered an OPRV from RGM about 5 years ago as the one my bike came with had been butchered by PO. They sent then SRM item shown above an it has SRM etched into it. It has a plunger inside which may or may not be stainless i cannot remember ever checking. It works perfectly an the the one time i took it part (just to check no swarf from resent engine rebuild had found its way in which it had not) there was no sign of wear or corrosion at all. I have an oil pressure gauge on my bike an the max pressure hot or cold is always 50psi. of course i am not claiming the gauge reads accurate but it consistently gives same reading which is all that matters.

    The plunger moves very little an quite slowly (compared to other engine components) to do its job an there is plenty of oil to lube of course so metal to metal gawling should not be a problem surely? Fit of one component to another, change in temperature altering the fit or contamination of particles in the oil its self would be more of a problem i would have thought.
    If i needed another i would order one again without question.
     
  10. JimC

    JimC

    Joined:
    Oct 12, 2007

    You get 50 psi at idle with hot oil?
     
  11. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    I run an SRM OPRV, so I hope they’re ok!
     
  12. Triton Thrasher

    Triton Thrasher

    Joined:
    Feb 10, 2009
    I use a 62-year old non-SRM, non-stainless valve. I’d take some convincing that the I’m using the wrong valve.
     
  13. toppy

    toppy

    Joined:
    Dec 2, 2012
    No Jim i did say max oil pressure 50psi. I gets just under 10psi hot at idle. So it seems to behave how manny say it should so that will do for me.
     
  14. JimC

    JimC

    Joined:
    Oct 12, 2007

    I failed to read max. Even so, 10 psi, HOT, at idle is very, very good. When I’d make the 50 mile jaunt to Daytona from my house, at +90 mph, my oil pressure at idle was more like 2-3 psi. That was with a new Andover oil pump and a fresh total engine rebuild. Many Commando owners are alarmed after installing a gauge by the low, less than 5 psi, pressure at idle when the oil is hot.
     
  15. tonybsa

    tonybsa

    Joined:
    Jul 23, 2017
    Yes,I am sure about SRM,I race sidecar outfits,previously an A70(750 A65).Its a pretty harsh envitoment for componants.
     
  16. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    The nice thing about the SRM/RGM valve is the fact that it fits tighter in the threads in the side cover so less oil bypasses the valve. That makes the oil pressure higher and slows wet sumping. It's a good unit. Comnoz

    EDIT,
    Maybe I better not give an opinion yet. I have had one of the SRM valves on my bike for a few years and did notice a increase in oil pressure at hot idle.
    But I have never taken it apart for a look so I cant say if there is any galling problems.
    I guess I will take it apart for a look.
     
    Last edited: May 16, 2018
  17. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    I use the SRM om my commando and like it very much. Oil pressure at start up is about 60 psi and settles down when engine oil warms up. At 1100 Rpm idle it shows about 18 psi on the gauge. I run dino oil straight wt in the summer. oh and with lots of zinc in the oil.;)
    Cheers,
    Thomas
     
    Last edited: May 16, 2018
  18. comnoz

    comnoz VIP MEMBER

    Joined:
    Dec 10, 2008
    I looked to see when I installed the SRM valve. It was only last summer. Around 8000 miles ago.
    I pulled it for a look. It does show some wear on the piston although it still slides freely.
    Guess I will look again next year. Comnoz
     
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  19. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    I installed the SRM during my rebuild @ 38151 odometer, and then onward down the road. (I keep a log book on my bikes). I just changed oil and filter at 63590. I didn't open the engine since.
    I have never noticed any issues with increase of oil pressure on my rebuild as Jim described. like I said down the road... Here is an honest shot. https://www.accessnorton.com/NortonCommando/60000-mile-stare.23187/
     
    Last edited: May 16, 2018
  20. olympus

    olympus

    Joined:
    Aug 5, 2017
    This is my though in another post.. the base of the OPRV doesn't seat in the bottom of the casing, the oil is stopped from by passing only by the tight threads
     

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