planning on replacing the oil pump in my motor (stock 5.0) while i have it apart.....

was looking at the melling HV oil pumps.... just wondering of any possible problems i might not be thinking of......


i will put a hardned pump driveshaft in, and will have a new steel distributor gear.....


can anyone think of any problems i would run into.... they advertise the pumps only flow like 20-25% more oil, so i dont think it will suck up all the oil from the pan, but i dont know for sure........ anyone had any experience here ?

 

Unless you're pushing some serious horsepower it isn't needed. For a stock motor retaining the stock pan it is unnecessary. Your engine's bearing clearances do not require the use of a high volume pump. Your motor does not stay up at high RPMs for extended periods of time and/or distance (think NASCAR). Whenever your oil starts to run low before tripping the low oil light you are sucking the pan dry. High volume oils pumps require more effort to turn compared to a stock oil pump. If you're going to run an oil cooler, higher capacity oil pain, or a turbo/supercharger requiring an oil feed line then a high volume oil pump would be a necessity. Other wise, if you're not doing any of the before mentioned stay with a stocker.

 

im with helmut 99% if you plan on having alot of gear you may want the hv, i have the hv in my car, when im doing a 6900 rpm bonzai run across the hf or gandy, i like seeing 90lbs of pressure, all i could get of of the standard pump was 60psi at best with fresh oil on the old combo.

your better investment would be a larger oil pan, like a 7qt one. not only do they look cool as hell, you pick up two more quarts of oil, it will keep the oil cooler, and you alway have the piece of mind that the oil will always be on the pickup tube.

 

well, this is my project car , which will see some beatings, not a drive to work everyday car, i cant see 20% more volume really doing too much, but i'd figure i'd ask around and see what some others have done.......

rubberneck, have you seen any temperature increase since the HV was installed?

 

No, it won't suck your pan dry. No, you won't have any issues with it.
No, you don't actually need it. Do you think your pump is going bad? It's a lot of work to replace a pump in a stang if it's not broken.

 

Lifting the engine high enough to slide the pan out, correct?

 

Dustin,

You don't need the high volume oil pump. An oil pump flows a set volume of oil. There are a limited number of exits from the pressure side of the oil system. The stock pump is sized for that. The only times you need to consider a higher volume pump are when you create additional flow capacity out of the pressure side of the system. If you add an oil line for a turbo or supercharger, you'll want additional flow for it. If you have the engine built and the oil holes are expanded to flow more oil, you'll want more capacity. If you run signifigantly higher rpm's, you'll want more capacity.

The high volume pump takes more power to turn. That decreases your total power output because it's parasitic drag. It also puts more stress on the cam.
Why spend energy running a pump if you don't need to do it?


Super high volume pumps can also introduce chatter as they spin. (Basicly as the gerotor inside the pump spins, the pressure behind the lobes of it increases and puts force against the cam gear. As each one releases it's oil into the pressure side of the system, that load against the cam gear is released. Picture what your car does when it's lagging in first gear and bucking. That gets transferred to the distributor and to the valves.)


My vote is to use a new stock pump that's been disassembled and blueprinted. One of the guys on the FFR boards does it for $75. He says that he gets 1-2 teaspoons of casting sand/metal shavings out of the average new pump. Let me know if you're interested and I'll track down his contact info.

 

And use a brass gear not a steel gear so you don't eat your cam up.