oil pump

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aaronk785

aaronk785

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Is a standard oil pump good to 7000 rpm in a unmodified block and factory clearences. Its a 340
 
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Modify via enlarging the oil paths, port the oil pump exit, port the main cap, use a deep oil pan, etc.....


Solid/solid roller cam?
 
road racer big NO
just miss a shift you might get lucky, might not
oil to the second crank throw is the first to go
pull the caps off the rods and check
 
Sorry I should of given more info. This is a existing engine. I lost the cam and it trashed the oil pump. Bearings look ok so I was just going to replace the hv pump with a standard one be cause I have a new one on the shelf. I've always used hv pumps but been reading that a lot of people say its a waste of hp and not needed. Motor has seen 7000 many times. Shift point is 6700 but love the sound at 7000.
 
Ordered a hv pump. Been using them for 30 yrs. Just being a cheap *** which usually doesn't pay off. Thanks for the advise everyone.
 
At that high RPM, if the relief valve is open and controlling pressure, it won't make a difference. Once the relief valve is open, the engine gets the same oil amounts from both pumps, assuming the std and HV have the same pressure relief valve spring. The HV just helps at the lower RPM's to get the pressure up faster as the RPM's ramp up. If you have large clearances and other oil system 'leaks', the std pump could conceivably not ever get to full pressure whereas the HV would have a better chance to get there.
 
A stock 340 left the factory with a stock pump... in those days there weren't and HV pumps.
 
right Krooser but stock clearances and hyd cam with weak springs- not 7000 rpm (for very long) but it's more worn lifter bores which is why all the oil mod threads
 
nm9stheham said:
At that high RPM, if the relief valve is open and controlling pressure, it won't make a difference. Once the relief valve is open, the engine gets the same oil amounts from both pumps, assuming the std and HV have the same pressure relief valve spring. The HV just helps at the lower RPM's to get the pressure up faster as the RPM's ramp up. If you have large clearances and other oil system 'leaks', the std pump could conceivably not ever get to full pressure whereas the HV would have a better chance to get there.
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This. We aren't working on chevrolets. The HV pump gets more oil "there" sooner but the total volume of flow is dictated by bearing clearances and internal leaks.
 
Krooser said:
A stock 340 left the factory with a stock pump... in those days there weren't and HV pumps.
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And plenty of stock 340s with stock pumps revved to and past 7K and lived.
 
I've just always had better idle pressure with the hv pump. It's up and running 25 at 800 rpm and 65 at 3000 so im good.
 
aaronk785 said:
I've just always had better idle pressure with the hv pump. It's up and running 25 at 800 rpm and 65 at 3000 so im good.
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25 at idle is the bare asked minimum if you are using roller tipped and needle bearing rockers. If you are running unbushed rockers (like the 273 rocker) or a bushed rocker its most likely galling the shafts, unless you have about 80 pounds of spring load on the seat and 200 over the nose. Even then, you are asking for trouble.
 
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