Speedway Motors oil pump vs. stock Ford (Mercury) unit

[tubman]

When I built my current 258" engine, I thought I'd save a few bucks and install a new standard volume oil pump from Speedway Motors rather than put a used pump back in it. When I got the engine on my stand, and broke it in, I was disappointed at the oil pressure that it showed. It was probably adequate, but it wasn't quite what I had seen on the used '51 Merc I had just put in my '51 Ford and most other 8BA's I had. There was some discussion on the forum that a used Ford pump was superior to a new off-brand, even a Mellings.

I decided to find out what was actually the case, so I went through my trove of used pumps and found I had two pumps, one from an 8RT of unknown mileage and use, and the other out of the '51 Merc I had put in the '51. (I had a problem getting the Merc to prime with it's original pump, so I used the one out of the '51 Ford engine, which I knew was good.) I sent these two pumps to our own "flatjack9" in Oshkosh, and he tested them and installed new relief springs. I am very grateful to Jack for doing this, as I have no resources to test the pumps. He sent both pumps back with a note for each giving it's properties (both were fine). Today, I just finished installing the Merc pump in my engine and getting it running.

Both times, I used fresh 10-30W Peak brand conventional oil that I buy from the local Dollar General on special. Here are the results of my tests :

Speedway pump : Cold idle - 20 psi, cold @2000 rpm - 57 psi, hot idle - 9 psi, hot @2000 rpm - 43 psi.

Mercury pump : Cold idle - 24 psi, cold @2000 rpm - 58 psi, hot idle - 20 psi, hot @2000 rpm - 59 psi.

Cold idle was taken as soon as I could get the choke off and was 700 rpm (the engine has a MAX-1 cam), the 2000 rpm figure was taken immediately after.

The Hot readings were taken after the engine had stabilized at 175° for 5 minutes (the engine has 180° thermostats).

In the final analysis, I am satisfied with the pressures produced by the Ford pump, but am uneasy with those from the Speedway pump, though they are probably adequate. I am not throwing any more 8BA oil pumps away.

Again, thanks to "flatjack9", without whose help I would not have been able to make this comparison.

[19Fordy]

Excellent peace of mind.

[Henry Floored]

This is great information, thanks!

[flatjack9]

Thanks for the report. Maybe I'll have to install a hotplate under my pan of oil to test hot output. If I ever get time.

[Ol' Ron]

I've always used stock ford oil pumps, since I had problems with the new Mellings pumps back in the 90's. I contacted Mellings and they said send them back and they would replace them. When I explained the problem, they weren;t interested. I put this information on the old Ford Barn, and found several other engine builders having the d\same problem. Others have found a number of problem with the castings and machine work. Since then I just check out the used pumps for excessive play in the gearing, sometimes removing the gasket is all it needs. Look for scoring inside the case, and maybe a new spring. I;d have thought by now they;d have fixed the problems. Maybe next year??
I also had JWL rebuild a pump for My Bville engine, he can test them

[JM 35 Sedan]

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I've used Mellings M19 oil pumps on my last two builds, '35, 21 stud, and '46-'48, 24 stud. Both pumps seem to be working well. The '35 engine is now @ 35,000 miles with no known oil pressure problems, but I must admit, I have not checked hot oil pressure lately.
Being a basic hoarder of early ford parts, I have saved all the old original oil pumps that I've removed over the years. My next builds will be two '36 LB engines, so on these I will try reconditioning two original Ford oil pumps instead of buying new Mellings pumps, and see what results I get.

[GOSFAST]

While I usually agree with Ol' Ron most times, I have never encountered a single "bad" pump from Melling, not one! This goes back to the mid '80's!

I've also learned recently that Melling was making Speedway's pumps at one point but not any longer as of a while ago, not sure how long! This makes me very suspect of Speedway's own brand? Also base this on their pricing!

There are so many products made "off-shore" recently you just don't know anymore what's good or bad. I do know that many of their Flathead rod and main brgs sets are definitely "off-shore". This doesn't mean all "off-shore" products are "bad" but we like to know for sure having to stand behind any builds.

Thanks, Gary in N.Y.

P.S. Going (way) back in time on some records here I can see over 200 Flathead pumps used in-house or sold "over-the-counter", all Mellings!

[drolston]

Spared no expense on overhaul of my 59A/B, except that I reinstalled to original oil pump, which had maintained close to 10 psi at hot idle on a a very tired engine with rods knocking. On the rebuild, it holds 30 psi at idle and pegs the 50 psi gauge at speed. I was persuaded by discussions on this forum that oil pumps are one part for which the old adage applies: "If it ain't broke ...... "

[Ol' Ron]

Must have been a figment of my imagination .

[tubman]

The Speedway pump involved in my test was purchased last summer. IIRC, Speedway listed both their own and Mellings pumps on their website when I ordered it, so this is most likely not a Mellings pump. I won't be using Speedway pumps to save a few bucks in the future, at least not when I have some old genuine Ford pieces around. I am going to post a review on their website and see what they have to say.

I do think that when I do install a used pump, I will check the end clearance (the only specification I can find) and will also install a new relief spring.

[JWL]

The only defective pumps I have ever encountered were Melling. In several examples the relief valve seat was not concentric with the bore?? How this can be done I will never know. One had the sealing shoulders machined undersize so oil leakage was excessive. I saved it by welding and machining a O-Ring groove to stop the leak.

[leon bee]

My new Melling pump, (in my first flathead) has worked flawlessly for 2 miles now.

Seriously, I've spent some time thinking about oil pumps and have discovered very little discussion of rehabbing old pumps. Maybe just missed it. And I've only seen a few rebuild kits for sale......90 bucks or so. To the uninitiated, it seems like you'd want more than just a new spring in an old pump.

Tubman: You mention buying a new pump to save a few bucks. Save as opposed to what? Can you send an old pump for professional rebuild?

[tubman]

Sounds like they don't need a rebuild, which makes sense seeing how they run in oil all the time. "flatjack9" will have to verify this, but I think all he did was test them to make sure they worked all right and replaced the relief springs. As I said above, the only spec I can find on the pump is (I think) .002-.006 clearance between the gears and the end plate. I checked both of the ones I had with "plasti-gage" and they were withing spec, so off they went. I would think that you're all right, because a defective pump like "JWL" describes would probably show itself right away with no or low oil pressure.

"Ol' Ron" or "JWL"; did the defective pumps show themselves right away, or were there other symptoms?

[flatjack9]

I have a lot of old pumps that I have removed from a lot of old engines. I check for wear or scoring in the end plate and seldom find a problem. That's why I built my test rig to verify that they are good.

[Pete]

It is not about agreeing with anyone. It is about what your personal experiences are with the part. When I was building wet sump engines I always used the Melling M15 pump. That is the high volume one. I never had a bad one. Idle at 1500 was about 50psi. 90 at 7K.

[Ross F-1]

Originally Posted by flatjack9

I have a lot of old pumps that I have removed from a lot of old engines. I check for wear or scoring in the end plate and seldom find a problem. That's why I built my test rig to verify that they are good.

Can your rig develop enough backpressure to lift the relief valve? (on an 8BA-style) Curious whether they vary much.

[JWL]

The stock Ford pumps, I have tested, are VERY consistent with relief valve openings at 55 to 58 lbs.

[tubman]

Originally Posted by JWL

The stock Ford pumps, I have tested, are VERY consistent with relief valve openings at 55 to 58 lbs.

That's what I saw.

Now that I have the numbers, does anyone have any idea of why the Speedway pump maxed out at 43 lbs hot? The relief spring is obviously close, as it was able to produce 57 psi cold, but it fell off badly when hot. If I had to guess, I would suspect less precise machining which makes for larger internal clearances that allow enough hot oil to "leak" internally, thus producing less pressure. Anyone else got any ideas?

[flatjack9]

Originally Posted by Ross F-1

Can your rig develop enough backpressure to lift the relief valve? (on an 8BA-style) Curious whether they vary much.

Yes and no.

[Bored&Stroked]

Originally Posted by tubman

That's what I saw.

Now that I have the numbers, does anyone have any idea of why the Speedway pump maxed out at 43 lbs hot? The relief spring is obviously close, as it was able to produce 57 psi cold, but it fell off badly when hot. If I had to guess, I would suspect less precise machining which makes for larger internal clearances that allow enough hot oil to "leak" internally, thus producing less pressure. Anyone else got any ideas?

Has to be clearances in my mind . . . just more "sloppy" than the originals.