Arnie...

Just threw the pump on a oil pump "dyno" that I made today.... A GM White Spring will do 80PSI if there is enough restriction for it, saw it with my own two eyes today the pressure relief valve does open at 80PSI, maybe I can get OldSStroker to help out and I can get a pic of the thing at 80PSI for ya.

The anti chatter grooves are basically there to keep the vibrations down to keep ignition timing accurate, a longer gear like a HV gear helps the same way. The HV also has the volume advantage also for larger bearing clearances.

BTW with the stock spring I never said you didn't have to shim the spring some to get the right pressures did I? Either shims or a adjustable spring stop.

Bret

 

No need, I believe you. Apparently, the restriction on my end, was not great enuf to generate that PSI. BTW, that was with extra shimming besides. Although, I have a tendancy to get over aggressive with the pressure bleed grooving on the ends of the gears, which may affect pressure. I know it affects idle pressure.My error for not explaining myself better. Not disputing the anti chatter grooves, just the similar merit from the HV pump.

 

Arnie to add to this I talked to a buddy of mine today who does circle track motors (one of his guys is on a 4 race win streak right now, and no it's not Tony Stewart) he uses a M55HV pump on his 355 motors with around .0030 clearance and the low pressure spring and he sees 60-65psi max in the motors. Volume is another way to get pressure, personally I like tighter clearances and a set pressure relief on a standard volume pump to get what I want.

Bret

 

I used to use the BB pump in all my roundy round engines. They now have these HV pumps so I use them.I use a HV on all my high HP builds 'cause most are set up with .0025 or better clearance's I also use the 3/4" pickup and a Canton road race pan on most(swinging trap doors) that's maybe why they don't blow up when the put um on the bumper, which several have.

 

Yeah if I open the clearances up I go with a HV pump but on .0020-.0025 NA setups (most times at .0021-.0023) I just stick with a stock GM pump. I also go with the trap door pans, windage trays, scrappers etc... really take care of the oil system and I don't run excessive oil in the pans either, easy way to eat up 5-10hp with too much oil in the pan of a stroker.

Bret