So I’m down to the final few pieces on my Prison Break 445 build. I was about to bolt on the Melling M-57HV and seal up the bottom end when the question hit me. Do I really need a high volume pump? And will using it do more harm than good? After reading countless threads on the subject, and MANY varying opinions, I haven’t been able to come up with a definitive answer. Obviously depends on application and use. So I’ll tell you guys what I’ve got and see if I can be pointed in the right direction.

1974 F100 2WD
390
Survival Prison Break 445 stroker kit
4.110 bore
4.250 stroke
stock cast heads fully reworked
Eddy Performer RPM
274 cam
no oil mods other than Holley jets in the heads

Truck won’t be a DD, but will get regular use.
Wont see a track, but may lay fresh prints at the occasional red light.

 

I'll give my historical take on this, after reading this forum and having lived through a few builds myself, and my own machnist's technical expertise on this matter. Some of the scenarios I'm going to list are related to both a brand-new build, and trying to fix an issue with an existing (maybe high-mileage) engine. However, the high-mileage engine scenario(s) help to explain some of the paranoia.

First scenario: Oil pressure is low when the engine is hot, got maybe more than 50K miles on it, have it apart for some other reason, and think that a high-volume pump will help solve the issue.
Results: Oil pressure is still low, but now it's flooding the heads with oil even more than it was. Can result in starving the oil pan for oil, causes all sorts of problems, maybe even catastrophic failure. Why? Rockers and rocker arms are so worn that they are passing oil way too fast, starving the low-end for oil. In reality, the outrageously high rocker-arm-to-rocker-shaft clearance is causing the low pressure at hot idle, and the high-volume pump just allows more oil to be pushed to the rockers, emptying the oil pan.
Take-away: High volume pumps cause head flooding and starvation.

Second scenario: Brand-new build, reuse old rockers and rocker shafts, use high-volume pump.
Results: Again, heads flood.
Take-away: High volume pumps cause head flooding and maybe even starvation.

Third scenario: Brand-new build, restrict the head oil galley, reuse old rocker arms and shaft, stock volume oil pump.
Results: nothing bad at least initially (those rockers and shafts will bite you in the *** someday however). Hot idle oil pressure is good.
Take-away: Head oil galley restriction is a good thing. High volume pump is useless.

Fourth scenario: Either high-volume or stock flow pump is used, rocker arms/shafts are new, heads may or many not have a oil galley restriction.
Results: Nothing bad, hot idle oil pressure is good.
Take-away: High volume pump is useless.

Each one of these scenarios is something I've read about here, and experienced in the real world. The real take away from all of this is:

1) Make sure you use new rockers and shafts, or ones that are as close to the stock OEM tolerances as possible. The more clearance between the rocker and the shaft, the more oil pressure they will bleed off. The head restrictors will help if the rocker arms and shafts are worn, and if you're looking at going for a lot of miles without ever working on anything head-wise, do the restrictors AND use new rockers/shafts. To be honest, using restrictors AND old rockers/shafts is asking for trouble down the road.

2) Bearing clearances based on what service life and environment you intend, and what oil weight you intend to use. Ask your machinist. If they don't know, find another one who does.

3) Use an oil pump that's high volume, or not, doesn't really matter, as long as you keep the rocker/shafts in good shape. Without a head restrictor, worn rockers/shafts WILL bleed off a lot of oil pressure (and oil FLOW) and cause problems in the low end. A head restrictor is a band-aid for this, but as all things wear, restrictors can help maintain lower-bearing pressure (and flow!) as the rockers/shafts wear.

The one thing I've sometimes done is to increase the oil pump bypass PRESSURE. High-volume pumps bypass a lot of oil if the pressure-bypass is not modified. This can actually help (maybe) oil temps overall because it's circulating more oil out of the pan and back to it. The result might be lower oil temps (I'd love to hear from anyone who ever checked for the difference). Or maybe not.

The one thing a high-volume pump will help with is keeping good oil flow as the motor ages and bearing clearances increase. Or if you use a thinner oil in the winter, and then don't change it quick enough as you hit summertime.

But all things being new, especially rockers and shafts, a high-volume pump won't help right away, but it can certainly help maintain a good oil flow as the engine ages. Any extra flow gets bypassed, and some might say that exercised the bypass valve too much, and it'll stick open - solution for that is, remove the pressure bypass valve, make sure it doesn't have any nicks or burrs that would impeded it's travel, and make sure your oil's clean at all times. Dirt can make the bypass stick open, starving the engine of oil at low RPMs.

Sorry, it's late, I gotta go to bed, and I might have rambled a bit here, but all I'm trying to do is add to the discussion so that we can hash it out, not tell people what to do

 

Wow! Great reply. New rockers and shafts ordered.

 

If you're going to be strictly on public streets then I don't see the need for a HV pump.

 

Ford never used a high volume pump on any FE even the high performance engines. The 427's and 428's were fitted with high pressure pumps but never a high volume pump (even for the SOHC 427). Ford did use a HV pump on the FT's but in that case it was needed for the extra capacity due to the air compressor oiling circuit on the air brake trucks. HV pumps also rob a little more HP than a std pump. They will however provide you with slightly higher oil pressure throughout the RPM range and for this reason alone a lot of FE engine builders use them on their customer builds (but not their own).

 

I love hearing from you guys who are so informed on the history of FE’s. This is my FE build and I have quickly fallen in love with it. Thanks for the responses!

 

I'd sure like to see a table of gpm for various standard and hv pumps for a laundry list of engines. Do we know any more about the flow rates other than "25% more" on the hv?

 

We got into a discussion and argument over this every subject a while back, no flow charts where ever produced.
I have a FT pump and FE pump but have taken them apart to measure the gears to see if one is larger than the other.

I used a high volume pump in a engine once, won't make that mistake again.

 

What happened and do you KNOW that the hv pump was the cause?

I'm curious because this really seems like a 50/50 division subject and it is good to hear from someone with actual experience on the matter. So much on the internet is perpetuated by people with 0 real knowledge.

I used an hv pump in my 390 and like a 70 jet restrictor. Time will tell...

 

I've been running a HV pump on my 428cj since 2008 with no problems. Is it necessary, probably not but on the other hand it hasn't caused any issues and at the time of the rebuild it gave me peace of mind for little cost difference.

 

Many years ago while still learning about FE engines we built a mild street engine with a Crane Fireball cam, headers and Holley carb. We used a set of adjustable rockers that had more wear than we where aware of and didn't know about oil restricters at that time.
HV oil pumps where the popular thing to use at the time so I used one to.
Long story short, the pump flooded the heads and pumped the stock pan dry resulting in some scored bearings.
A stock volume pump would have had lower oil pressure due to the worn rockers which would have alerted us of a problem and it would not have pumped the pan dry.

Yes a good set of rockers and oil restrictors would have taken care of the problem, but if everything is in good shape and getting properly lubricated why would one need a HV pump.

 

The theory of getting more oil pushed to the main bearings is what people get back to. Whether or not that is valid... Who knows.

 

Like many others this has always puzzled me. Just my opinion but considering the oil galleries in the engine are a certain size that limits the volume, and the only way to increase volume is to increase the pressure, seems like a simple physics problem. So is a HV pump just a higher pressure pump? Or is it a higher volume if the galleries were enlarged to handle the volume?
I did you use a HV pump on my 390. Solid lifter 427 cam and adjustable rockers with restricters in the heads. Has awesome oil pressure and has never had a problem.

 

By this logic, wouldn't opening a hydrant 1/2 way give you the same amount of water at the other end of a hose as it being fully open? The supply pressure is the same and the hose is "full" in both cases. You are increasing the flow to maintain the pressure down stream.

Similarly, a higher ampacity (volume) power supply will allow you to have more outlets where lights/motors/whatever are pulling current. When you build a new shop, you do not strive to crank the voltage up to 10,000V to allow more tools to be plugged in -- you put in a bigger wire and breaker panel with more amps.

The oiling system has many places to leak along the way, and theoretically you should be able to maintain the flow and pressure downstream with more flow up front.

Edit -- The intent here is not to argue, but to show both schools of thought. This discussion always ends up the same way: There are no true numbers to back anything up (i.e. oil pressure readings at various down stream places in a short block), so we are left with gut feels.

Who wants to put together an engine just as an oil pressure test mule with me and put this to rest??? I actually have an engine that I might be able to put together just for this purpose. It is a worn out engine, BUT it WOULD prove or disprove the theory that there would be more or less pressure downstream with upstream "leaks."

 

The oil pumps on most stock engines have a pressure relief valve that will limit max pressure to around 60 psi, at idle or low rpm with the oil pump producing less flow there may be only 30-40 psi due to leakage around bearings, lifters, rockers ,ect. As rpm's are increased oil pressure rises because of the increased flow from the pump until max pressure is reached and the relief valve opens.
Some factory performance engines (I've only worked with Fords) have oil pumps with relief valves set for higher pressures, the ones I've used normally show around 72 psi on my gauges, the higher pressure pump well force more oil thru the same passages than the same volume pump set for a lower pressure. The engine will still show the same 30-40 psi at idle because the volume is still the same, but will be feed more oil in the higher rpm range where it's needed in performance apps.
Most high volume pumps I've seen produce 25% more volume and also normally come with the higher pressure relief valve in the 72 psi range. Now at idle the engine has 45-60 psi which looks good and makes one thing they did a good thing, but at higher rpm the pump is now producing more oil than the oil system can handle forcing the relief valve to work more sending high pressure oil flying back into the crank case.
On a FE engine with no restrictors to the heads and a set of worn rockers and shafts the higher volume produced by the pump can flood the heads and in my case empty the oil pan damaging the engine.
Most mfg's of hv oil pumps recommend one to also install a no stock oil pump with a higher oil capacity to help prevent the possibility of empyting the pan, but no many do that on a street driven app, they don't want to pay the cost or don't want a low hanging pan on their street driven vehicle.
My view is a hv pump will make idle oil pressure look better but beyond that they work against you.
FE engines are well noted for having low idle oil pressures, I've seen several low miles FE's with only 15-20 psi at idle, but the oil pressure will increase quickly above idle.
This is a tale tale sign of to much oil going to the heads or of a well worn engine.

So here's my take today, if Ford could get 427's, 428CJ's and any of their other performance engines to live under the demands of drag racing, NASCAR and Le Mans with a standard volume oil pumps, why should I need a hv pump for my engine.

Edit: Just found this info on a old net 54 thread

Melling oil pumps for FE engines
gpm ratings are at 4000 rpm

M57 22 gpm - 60 psi relief
M57B 22 gpm - 70-80 psi
M57HV 27.5 gpm - 70-80 psi
M57HP 27.5 gpm - 100 psi
No info on M57A FT truck pump
C3AZ-6600-B 427 pump 22 gpm - 70-80 psi

M57B would be my choice.