I need a new oil pump for my new 383 build. I was ready to get a Mellings 10552 (http://store.summitracing.com/partdetail.asp?autofilter=1&part=MEL%2D10552&N=700+115&autoview=sku) ,but then I saw this Melling 10552C (http://store.summitracing.com/partdetail.asp?part=MEL-10552C&view=16383&N=700+) which is the same except has anti-cavitation grooves and says "for racing only". Would it be o.k for a weekend warrior? Why does the anti-cavitation grooves make it "race only"?

Thanks,
Mike

I would just go with the 10552 for the street. The anti-cavation grooves will result in lower oil pressure at idle.. very low if you also happen to be running a solid FT with EDM lifters. Many builders may say that low idle pressure is not really an issue as long as you have some, but many street rodders might be more comfortable with seeing a little more on the gauge. Unless you are seeing lots of high rpm, I wouldnt even bother with the "C" pump for the street, though.

mike

We have been using the 10552 with zero problems

is the 10552 the one with the weaker casting that everyone was so paranoid about breaking a couple of years ago?

No.. the weaker casting is the M55 pump. The 10552 is the M-select pump with a heavier casting and other improvements such as a bolt on pick up and the bypass spring in a housing with a threaded cap rather than a roll pin to hold it in.

Select series is the only good choice for a SBC oil pump anymore. Besides the anti-cavitation grooves on the C series those 3 C series pumps as well as the 10555 and 10990 which are both HV 25%, rather than 10% like the 10552, are shown to not have pinned drive gears. I will say my 10552 was not supposed to have the anti-cavitation grooves, but did have them milled under the ends of the gears. It did not have them up the inside of the pump body however, so maybe that's all you gain with the C series. I thought the real purpose of these grooves was to hydrostatically balance the gears to prevent spark chatter in the distributor at high rpm.

Can't go wrong with the standard 10552. It's certainly the pump I'd choose again.

10552 here also, great pump.
http://www.camaros.net/showroom/data/531/pump.jpg

The new mellings select pumps that i have seen have powder metal gears IMO. this s@cks Glad i have a couple of old ones with with billet gears.

I've had others tell me they changed over a few years ago, but the 10552 Select I have currently was purchased a year ago and still has the steel gears. Maybe I got lucky?

Thanks, I'll get the 10552. Hopefully it will have the better gears.


Mike

No.. the weaker casting is the M55 pump. The 10552 is the M-select pump with a heavier casting and other improvements such as a bolt on pick up and the bypass spring in a housing with a threaded cap rather than a roll pin to hold it in.

did they ever fix the problem?

i have the m55hv (although it is at least 15 years old, so its not part of the new, crappier castings)

I'm running the 10552 in my current engine. 10w30 oil, solid lifters w/edm hole, pressure at 750 rpm's never lower than 18psi.

Select vs the one that destroyed my 400:
http://i213.photobucket.com/albums/cc31/lonphotobucket/383/new383012.jpg

I'm running the 10552 in my current engine. 10w30 oil, solid lifters w/edm hole, pressure at 750 rpm's never lower than 18psi.

Lonnie.. which pump bypass spring are you running, which EDM lifters are you running (each brand has a different size EDM hole) and what are your clearances like? How much did the EDM lifters drop your oil pressure?

mike

I've personally never used a Mellings Oil Pump so I can't comment there; but, I've been using the TRW Tall pump without the slightest indication of trouble. The casing is very strong and the same TRW part is used for both SBC and BBC.

Melling Select is the way to go! a couple bucks more is worth a good peice of mind!
Have one on my 406!

Lonnie.. which pump bypass spring are you running, which EDM lifters are you running (each brand has a different size EDM hole) and what are your clearances like? How much did the EDM lifters drop your oil pressure?

mike

What ever spring came with it, it is the +10% Z/28 style pump. I'm running Comp Cams lifters. .002 rods .0025 mains. Oil press drop- I'd say none, but no direct comparison. This was the 1st time I didn't run the full HV pump and my pressure is higher than any other engine that I've had. My Craftsman 1/2" drill didn't struggle when priming the engine like it did with the full HV non "Select" pumps. It's nice to see something that cost more actually work better.

My 10552 came with 2 springs, depending on how much oil pressure I'm going to want I'll decide which spring to use. Also old Z/28 M55 pump was a good pump before they lightened it, but the 10552 has almost nothing in common with it today. Improvements beside the heavier casting are CNC machining, steel gears with chamfered edges, mag phosphate coating, threaded retainer for the regulator spring, 3/4" pickup that's bolted on rather than the 5/8 pressed in pickup, gear end play reduced, shaft supports for both idler and drive gears, hydrostatically balanced gears, to name a few improvements.