issues with mellings pumps have been cleared up a few years ago.

 

oem pumps never seem to fail.

 

10 percent by hi vol. melling part number is 10552 .. (***bolt on pick up**),bigger gears , anti cavitational chamber ,(dowled)bypass, valve is allen screwed in .....melling is the way to go heres the part numbers for you..
7 inch is #12557
7.5 is #12558
8 inch is #12559(length of pick up tubes)..

 

Any Mellings Select series. The one mentioned above , 10552 is one of those pumps.

 

I use the Melling (Select) #10554 for almost all street rebuilds - both stock and performance.
For performance usually the only mod I do is to install the "white" GM spring to increase upper end pressure @10lbs.
There is no reason to increase the volume in a street driven small block :noway: and lots of reasons NOT to :yes:
This same pump is sold under many companies names as their "Performance" unit

This pump has the high strength base and will not crack at the mounting like the weaker stock and M55 types.

Stock ... #10554

Also weld the pickup (usually stock GM) to the pump for added protection.
To get the location correct;
* remove the stock pressure spring from the pump
* mount the pump to block
* lightly insert pick-up into pump, with it slightly angled away from block, with a few slight taps - just to hold it
* set pan on block rail, without a gasket so that it contacts the pick-up and push down on pan to set pick-up to pan depth
* remove pan and tap the pick-up down an additional @1/4" from position pan pushed it to
* finish tapping/driving the pick-up into the pump to fully seat it against pump
* unbolt the pump cover (4 bolts) and remove
* weld/braze the pick-up to the cover (off the pump) [note: I use my MIG and a small weld to do this - I used to braze, but think it builds more heat in the part than the MIG weld does from a test with a IR Heat-gun - so I weld only now.]
* cool the assembly
* install the original or the new 'white' GM pressure spring
* reassembly cover to pump and finish build

hope this helps;
John

 

I use the Melling (Select) #10554 for almost all street rebuilds - both stock and performance.
For performance usually the only mod I do is to install the "white" GM spring to increase upper end pressure @10lbs.
There is no reason to increase the volume in a street driven small block :noway: and lots of reasons NOT to :yes:
This same pump is sold under many companies names as their "Performance" unit

This pump has the high strength base and will not crack at the mounting like the weaker stock and M55 types.
View attachment 13744
Stock ... #10554

Also weld the pickup (usually stock GM) to the pump for added protection.
To get the location correct;
* remove the stock pressure spring from the pump
* mount the pump to block
* lightly insert pick-up into pump, with it slightly angled away from block, with a few slight taps - just to hold it
* set pan on block rail, without a gasket so that it contacts the pick-up and push down on pan to set pick-up to pan depth
* remove pan and tap the pick-up down an additional @1/4" from position pan pushed it to
* finish tapping/driving the pick-up into the pump to fully seat it against pump
* unbolt the pump cover (4 bolts) and remove
* weld/braze the pick-up to the cover (off the pump) [note: I use my MIG and a small weld to do this - I used to braze, but think it builds more heat in the part than the MIG weld does from a test with a IR Heat-gun - so I weld only now.]
* cool the assembly
* install the original or the new 'white' GM pressure spring
* reassembly cover to pump and finish build

hope this helps;
John

John what Melling pickup part number oil pickup would you use with the Melling #10554
pump. You mentioned a stock GM pickup; wouldn't have a part number by chance.

Thanks to all for the information!

John Lighthart
Charleston,SC
1/15/2010

 

No :noway:
There was a company that included a gasket for that location in their overhaul kits years ago ... they had hundreds (maybe more) of claims of engine failures and damages
The pump would 'walk' on the gasket and squeeze it out over time and then the bolt would continue to loosen until the pump either fell-off or the drive coupling broke ... then no oil pressure :sad:

Just clean both mating surfaces well and be sure there are no burrs or dings from handling on the machined interfaces and install the pump to main saddle dry.
Be sure to install the distributor drive shaft and coupling before mounting pump!
Lube the bolt with a slight amount of light oil and torque to recommended setting - do this in two(2) pulls; 1st @40~45ftlb and 2nd to final 60~65ftlb.

You're good for another 100k ... or until you need more power (insert 'Tim Allen' sounds here)

 

The Select Series Mellings 10554 would be a perfect pump. But if you want to use the bolt on pickup you have no choice but to look at the high volume Select Series Pumps. I agree there is no reason to ever use a high volume pump on a street/strip SBC, but I opted for the 10552 simply to get the bolt on pickup. It's only 10% high volume, so not a big deal, the 2 Select Series pumps with bolt on pickups are 25%, didn't want that.

Also a lot of guys have had OEM style pumps break, some have posted about it here. Those are since the weaker casting that came out in the 90s at least. Mellings fix for performance pumps was the introduction of the Select Series. Two years ago Mellings told me directly that their OEM style pumps still aren't acceptable for any performance build, they persuaded me to purchase the Select Series.

 

Haven't had a Mellings HV pump standard pump fail ever - not to say they won't, but I've used them for 30 years without a single problem. I would speculate that many of the failures are from poor installation procedures like not torquing the bolt to specs or banging on a press fit pick-up into the pump while the pump is installed on the rear main which repeatedly bangs the pump neck till weakens and sets it up for early failure.

 

Steve I've never broken one either, but when Mellings tech rep says don't use our standard M55 pump in it's current light casting, that's all I had to hear. Moroso also won't response to questions regarding did they continue to use the weaker casting in their blue print series pump. A couple people have chimed in that have had the weaker casting M55 break in their drag cars. In these cases the guys were running solid motor mounts, sticky tires and launching their cars hard, ect. Severe duty. Contributing factors, probably, but who knows for sure what they did to their pumps at install like you stated.

The last 355 I bought and tore down the pick up literally fell out of the pump when the oil pan came off. It was that loose a fit. I always brazed mine on, but now there is no need to if I use a Select Series with a bolt on pick up. For a few dollars more the Select Series Mellings pumps are a huge improvement, steel gears, pinned gears, dowel locators in the pump covers, mag phosphate coated, heavy casting, hydrostatic balanced, bolt on pick up tubes just to mention a few improvements.

I used to run the M55 also, most of us did, but back before they weakened the casting. The M55 you ran 30 or even 15 years ago is a different pump from the M55 they build today. Mellings did us a disservice by continuing to carry the same part number so guys who used to run a hi-perf M55 pump back in the 70s and 80s think the M55 today is the same quality pump. It's not. Mellings say's don't use it for performance use. There are tens of thousands of them in use today and only a handful may fail, but there are a lot of other improvements in the Select Series that will make you not even consider the M55 if you take a careful look at them.

 

Thanks for the info - now I have something else to worry about with my new build! I thought for sure I read on the mellings web page not to use the select pumps for street application which is what mine will be primarily so IO went with the M55. When I put the new pick up on mine it took quite a few blows to get it seated fully with the special pick up install tool from Summit. Its not coming off for sure- and the pick up is bolted on to 1 of the pump bottom bolts for extra assurance,(that bolt's red locktighted).

 

I have been doing A LOT of reading lately and everything is saying that for a street car, a STOCK GM pump is MORE that sufficient. I have always been the guy to run a high volume/pressure pump, but after everything saying the GM small block standard pump is more than sufficient, I will be using a stock pressure/volume pump in the future.

 

I'm starting to think this whole hv/hp oil pump install thing started just like the whole "I want race car parts in my car" though it's a street/strip car, regular parts work just fine.
HV pumps aren't needed on most of our cars, just like full mechanical advance doesn't really have it's place either, unless your running boosted apps or a straight up off trailer on trailer race car.

 

I'm starting to think this whole hv/hp oil pump install thing started just like the whole "I want race car parts in my car" though it's a street/strip car, regular parts work just fine...

:yes: "regular parts work just fine" :thumbsup:
You just nailed it when it comes to a small block ... or even most big blocks.
The engineering that went into the small block is just amazing on many many fronts - and oil system is an outstanding example!
Unless you are purpose building an engine that has operating parameters way outside of the norm, then any major oil system modifications - like radically increasing pressure or volume, redirecting flow or limiting drain back - are just plain old not needed. And a waste of money ...

You are correct in saying that the majority that do wierd and exotic modifications to the oil systems and use midified pumps are mainly doing it because of the 'I want race parts in my car' factor - they have no idea if it helping or hurting their output or reliability.
Modified pumps place increased loads on the valve train, at all the wrong places.
They load the cam and distributor drives causing very rapid wear of those components in many cases.
I worked on one engine built by someone else for a friend that kept eating distributor gears - we of course first suspected that the dist. gear was not compatible with the cams ... nope, a bronze gear lasted about two weeks ... next, knowing that sometimes a cam needs to 'eat' a new gear or two before it beds itself in correctly and the gears will survive, I threw another good bronze gear at it ... it to was gone in a couple weeks - while he was on a cruise Finally took a real good look at the gear on the roller cam fiquring I would see some damage or probelms, it looked just fine with no wear marks at all, so I called the cam manufacture for different gear recommendation - they were blown away that it was eating gears and had never heard of the type we were using not lasting a reasonable amount of time. Searching for an issue, I started to check some other things and one of them was 'why' the pump drive seemed so hard to turn after one or two revolutions. I installed my oil system primer drive and hooked up my 1/2" Milwaukee drill and gave the drive a few turns - it grabbed the dang drill right out of my hand at that point Bottom line, I pulled the pan, removed the pump they installed, reinstalled and good standard pump and slapped it back together - problem solved, next gear is still going strong ...

I dont understand this need to braze the pickup to the pump. I just replaced my pump not too long ago with a M55hv and my pump had a provision for me to bolt my pickup to the pump, which I did. Is this because it was a 55hv?

Melling (and a few others, most of which are 'Melling' castings ) offer bolt on pump pick-up bases.
These are for ease of assembly and service, as well as adding an additional safety factor to the possibility of the pick-up falling off.
I have seen a few of the bolt on units fracture the bracket at the pump and the pick-up fell off anyway - but this is on radical marine engines and Class-8 Off-Road trucks that take an amazing amount of pounding.

Throught the years there have been many common methods of decreasing the possiblity of the pick-up vibrating or being jarred off of the pump.
We often fabricated a bracket, welded it to the pick-up assembly and used one or two of the pump cover bolts to retain it.
We also used to fabricate a mount to the stud girdles when we were using them on some endurance engines and in high-output marine engines.
One company (IIRC it was Milodon ...) offered a replacement pump cover assembly years ago that used a modified Ford (they've used bolt-on pick-ups for years) pick-up.

As far as when you would use either a High Pressure or High Volume, I use two very simple rules ... and they hardly ever would apply to a 'street' vehicle
High Pressure - when larger clearance spec.s are required for main and rod bearings. This pump will maintain the pressure in the system throughout the RPM range for short duration match-race engines.
High Volume - when the engine is meant to be operated in the 6~6.5k +RPM range for extended periods of time. These pumps can maintain the needed pressures and flow at these higher RPM levels on endurance engines used in some forms of racing - like NASCAR and INDY stuff.

Hope this helps and others chime in with their input;
John

 

Lots of good points. Stock Chevy pumps work great, always have. Stock Chevy oil system is pretty much bullet proof out of the box. No need for race part on a street driven SBC, spend your money elsewhere. I've never known a M55 pump to have a bolt on provision as part of the pump, but maybe I've missed something. I have used M55 pumps with pickups that have brackets designed to bolt to the pump cover bolts, these work great. But when I say provisioned for bolt on pumps the pickup boss is drilled and tapped to install a special bolt on pickup tube. I've seen pickup tubes that were pressed in fall out, not ones I installed, but on an engine I tore down I had one fall off. I've brazed regular pressed in pickups myself to make sure this never happened to me, it's easy to do.

Regarding the Select Series Mellings pumps I know of ten different part numbers for the SBC and only 3 of these are race pumps. The other 7 are street strip pumps and listed as such by Mellings. If it's a race only item the part number has a C at the end (10552C, 10555C and 10990C are the race only pumps). These three pumps have machined anti-cavitation grooves milled into the pump housing and cover. One of the things this does is to hydrostatically balance the gears and prevent spark scatter by the distributor.

If you want the M55 version of the Select Series pump there are two Select Series that are standard volume, 10553 and 10554. The first one has a 5/8 pickup inlet, the second has a 3/4 inlet. Use the 10553 and it's a much better pump, read this as longevity and reliability NOT romanticizing race parts.

All 7 Select Series street pumps have mag-phosphate coating and steel gears. Pumps 10 550, 10551, 10552, 10553, 10554 all have pinned drive gears. Pumps 10550, 10553 are the only ones with 5/8 pickup inlets. Pump 10552 in addition to already mentioned items also has shaft supports machined into the pump cover, a screw in bypass plug, a provision for a bolt on pickup (only non-race pump to have this feature) and in the case of my 10552 some of the anti-cavitation grooves machined, but not all like the 3 race Select Series pumps. The 10552 is 10% high volume, a feature I do not find necessary or want, but to get the other unique improvements I opted for this pump.

While high volume isn't ever necessary on a street pump there are 4 non-race Select series pumps that are available in high volume for other applications. These 4 pumps are 10550, 10551, 10555, 10990. These are all 25% high volume, so I wouldn't even consider these 4 pumps.

If you eliminate those 4 pumps and the 3 race Select Series pumps you are left with 10553 & 10554 the M55 replacements, or 10552 with 10% high volume and a bunch of features not offered in the first two pumps. Those are really the 3 pumps to consider. You can still run your M55, it'll serve you well on the street. But for $25 more if you want a CNC machined pump with steel pinned gears that isn't the weaker casting of the current M55 consider one of these three. By the way I drilled the internal wrenching allen head bolts on my pickup tube and used .032" stainless steel lockwire to safety the bolt on pick up to the pump. Something I'd recommend or even simply red loctite.

 

This thread makes me want to pull my motor again this winter to see what pump is in it, the pressure seems in the norm, but even after about 3,000mi we did notice the distributor gear had unusual wear, good point on that. (flat tappet cam, std. cam gear &dizzy gear)
It does have a bolt on pick up from what I remember.... Distributor walk, and play could cause this as well.