Oil pressure relief valve, was oil pressure gauge

[Bullwinkle]

Barney, Bill, Chip, Lawrie, Skip, and all other racers and mechanic freaks: <<>> my MGA lost oil pressure completely at about 7000 rpm because the oil pump was cavitating. <<>> Okay, that comment has me thinking, terrible thought that is. Where does the excess oil from the relief valve go to? Into the sump or back into the pump? On the B series engine where does it go? On the XPAG engine where does it go? Was the effect of raising the oil pressure on racing engines actually to decrease the flow rate at high RPM's and therefore reduce the oil cavitation problem in the pump? This question of course depends on where the excess oil from the pressure relief valve goes. Blake

[Skip Kelsey]

Blake: Are you sure that it was cavitation? Do you have a crossdrilled crank?Did you modify the pump for more volume,per the book? If you do not, then that could be your problem. At 7000 RPM and above you will lose the engine for sure without crossdrilling the crank. Skip ...................................................................At 10:50 AM 5/22/02 -0600, Bullwinkle wrote:

>Okay, that comment has me thinking, terrible thought that is.

[AJChalmers@aol.com]

If I recall from inboard/outboard motor cavitation, the prop creates a "cavity" in the water, therefore losing its bite in same. I guess oil pumps can do it in oil.

[Jennifer and Hugh Pite]

Cavitation is a result of a low pressure in the fluid caused by the moving metal parts (propellor). If the pressure is below the vapour pressure of the fluid the fluid vapourizes and forms a gas or, in other words, the fluid boils without the addition of any heat. The small bubbles formed by cavitation quickly collapse when they leave the local region of low pressure and can cause vibrational damage to the propellor, pump, valve or what-have-you. Hugh Pite '48 TC 33' J-2

> If I recall from inboard/outboard motor cavitation, the prop creates a > "cavity" in the water, therefore losing its bite in same. I guess oil

pumps

> can do it in oil. > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ > >