Oil pumps for 351w block

V-8 · #1 (**permalink**) 02-22-2004, 03:37 PM

Anybody suggest me a good oil pump and oil restrictors for my 351w block.Thanks...

Bruce Edwards · #2 (**permalink**) 02-22-2004, 03:57 PM

We use Melling HV/HP pumps in all of our engines. Never had one fail in 20 years of building engines.
Restrictors??? what are wanting to do?

V-8 · #3 (**permalink**) 02-22-2004, 04:13 PM

I'm using mechanic roller cam and i want to increase oil pressure with restrictors.

Bruce Edwards · #4 (**permalink**) 02-22-2004, 04:57 PM

If you have the engine set up correctly it will make up to 80psi and that should be more than enough for anything you want to do with out having to use restrictors.
Use a good oil pan with baffles and you should not have a problem.
Just my 2 cents.

V-8 · #5 (**permalink**) 02-22-2004, 05:14 PM

I read in a Ford performance book."oil pressure must increase 10psi every 1000rpm".So my engine redline 6800rpm,70psi gets enough.

Bruce Edwards · #6 (**permalink**) 02-22-2004, 08:00 PM

You should have no problem with that if you install that pump and your bottem end is in good shape.
We use that pump as I said and have spun some of my motors to 7500 with out a oil starvation problem. I have a Melling pump on my 340-6 in my 73 Charger that I was spinning to 8,000 and never had a bottom end oil problem.
Just be sure to use a good pan and pick up.

Keithc8 · #7 (**permalink**) 02-22-2004, 09:31 PM

We like to use the Melling HV or their blue printed oil pump that has an adjustable relief spring plug. We will normally have no problem with the standard HV pump but because of tolerances in the pumps and the lifter holes on some of the stock blocks as well as bearing clearances choosen we will want to boost oil pressure a little when we dyno test. If you are going to run a solid roller I would recommend restricting the oil to the top end of the engine or you may pump the oil pan dry with most of the oil going to the top of the engine. We use restrictors that we have made that screw in where the lifter galley plugs normally go. These run about 25.00 and work great. you will also want to make sure the solid lifter you choose has the groove in the lifter line up with the lifter galley or you may burn some pushrods. Leaving the restrictors out does not solve this problem as some would have you believe. It is a lifter galley and groove in the lifter alignment problem. We saw this problem many years ago and it also depends on the block you use. Some of the late mmodel and the race blocks have the lifter galley moved up in the block. Good luck. Keith Craft

Rick Parker · #8 (**permalink**) 02-22-2004, 10:37 PM

www.melling.com/highvol.html

They offer one that allows the shaft in the gerotor to extend into the bottom plate.

Rick

Rick Parker · #9 (**permalink**) 02-22-2004, 11:02 PM

www.precisionoilpumps.com

Good prices, good work, quick shipping

Rick

MidOHasp · #10 (**permalink**) 02-23-2004, 09:56 AM

To shift gears, I have a question...

I'm running a hydraulic roller cam. Melling M83 standard vol pump (at the recommendation of some builders who said that the high vol pump can wear down the distributor gear or something to that effect - it's been so long I forget the exact advice.

I've heard some people say similar things about oil pressure and boost from a supercharger - pressure is only a measure of pressure, and in this case, it is back-pressure. You have to measure volume to see what's actually flowing (i.e. - 8lbs of boost on heads that flow 200cfm is better than 10lbs of boost on heads that flow 15).

Bottom line, I'm seeing pressure shoot right to 60-65 psi on a cold start, then as the oil gets hot, it drops to about 30 at idle. On take-off, it pops up to about 45-55 psi and stays there pretty much from 2K-6K rpm. I'm not running over 6K but am considering changing our chip to 6500. I'll never run over that.

I've heard that as long as you have oil pressure (a reasonable amount, I'm not talking about 10-20psi), you're good to go.

Am I risking starvation only having 45-55psi at 6K rpm?

auto10x · #11 (**permalink**) 02-23-2004, 11:02 AM

Midohasp,
You'll do just fine with 45-55 psi @ 6K RPM>
auto10x
Bill

Bruce Edwards · #12 (**permalink**) 02-23-2004, 11:03 AM

Rule of thumb is 10 psi for every 1,000rpm. If you are turnig over 6,000 and your max pressure is 55 you are running on the low side. Try going to a straight grade 40 race oil that should help some.
If you look at the Melling link that someone put up it shows all the miths about HV/HP pumps. Most folks that tell you the kinds of things you have heard are not as smart as they think they are. We use the HV/HP pumps in all of our performance engines and have never had a problem and I have built a lot of engines in 20+ years.

brainsboy · #13 (**permalink**) 02-24-2004, 08:17 AM

I bought a motor once that was putting out 100psi oil pressure. I ran it for about 2 years that way before rebuilding it. I noticed that someone had changed the spring in the oil pump to put out more psi. The motor was in great shape when i did the tear down, bearings looked good. Why dont they make pumps that have 100-120 psi normaly? Would there be any ill effects from doing this kind of psi with all performance motors?

Bruce Edwards · #14 (**permalink**) 02-24-2004, 11:23 AM

The problem I have seen at those kinds of pressures is the stock oil filters tend to blow apart. You do not need 100 psi unless you are spinning 10,000rpm.

brainsboy · #15 (**permalink**) 02-24-2004, 01:37 PM

Have to use an oil filter girdle I guess

Bruce Edwards · #16 (**permalink**) 02-24-2004, 01:43 PM

I had a car come in my shop that someone "Fixed" the oil pump on. It kept blowing the rubber seal out of the filter. When I ran a pressure check it showed 135 before the gasket went. Turned out he "Overhauled" the pump and drove the spring cap for the relief valve half way down the bore.
Put a new pump in that one. A girdle would not have helped that one.

Mr.Fixit · #17 (**permalink**) 02-25-2004, 08:11 AM

Quote:

Originally posted by brainsboy

I bought a motor once that was putting out 100psi oil pressure. I ran it for about 2 years that way before rebuilding it. I noticed that someone had changed the spring in the oil pump to put out more psi. The motor was in great shape when i did the tear down, bearings looked good. Why dont they make pumps that have 100-120 psi normaly? Would there be any ill effects from doing this kind of psi with all performance motors?

Yes, there are ill effects from running too much oil pressure. Look at a bearing chart, they usually have a picture of a main bearing that has holes in it's babbit from too much oil pressure. Not to mention that extra work your timing chain has to do. And you can't puch that much oil through a motor, it just squirts out the pressure relief on the pump. Your motor is working extra hard to build all the excess oil pressure, and it just gets sprayed out a relef valve.