Just curious to see if anyone is using on of these oil pumps. The Moroso claims to have some special coating or material to help with cold starts, in addition to having the grooves to smooth out the oil being sucked by the pump. The Mellings appparently has too low of an Idle PSI for marine use but I have heard the Moroso still has a good Idle PSI.

Any input?

Several boats in our group, including me run the Melling 10778 pump. If that helps any.

iv been useing the mellings pumps for years with no problems.

installed the melling anti cavitation pumps and oil pressure @ idle after a hard run ( 235 - 240 degree oil temps ) is 25 psi ... just a tap on the throttle ... 45 psi . not a problem in my book !Bearing clearances @ .003 rods and mains

10778C Mellings. Work great.

I have a Melling M77HV in one engine and a 10778C in the other. One bounces around after a hard run between 25-35psi. (can't remember which one) Probably just the sending unit. 70-80psi cold idle.

I also run the 10778, 60-65 psi cold idle, well over 20psi after a hard run @ 650 rpm. Just kicking it to 800 rpm I see about 30-35 and over 40 by 1000rpm. Cruising on boat I see 50-55psi. Honestly see no need for anything special.

Ditto for me too-same EXACT results, hoyt pressure at 900 rpm's is 20-30 psi, not too low for "marine" use. When I tore my motor down from last time my Melling hardened oil pump drive was 1/2 sheared off so I figured maybe somethiong was going on with my previous 10778 at high rpm's and used the C pump this time, Smitty

To be clear, in my understanding the 10778 and 10778C are two different pumps - with the latter having the grooves machined into the cap for anti-cavitation in racing applications. They do warn about low oil pressure at low RPM's with that one.

Arctic, it's funny that you mention the damage to your drive - my distributor gear was badly worn on mine and I was also running the 10778 (non-"C") pump with 20W50 standard oil. Did you have any wear on your gear?

I discussed this subject with Bob Madera a couple of weeks ago, and he advised running the 10777 pump. His feelings are that extremely high oil pressures are unnecessary, a waste of HP, and possibly detrimental to the oiling system.

I run a TiTan Pro series pump in my blown 540...I have it set at 70Psi little higher than I wanted. It drops 10psi about 60psi at idle. Going to drop the psi more the next time the motor out. The Titian is a high volume flow pump so it doesn't need the hi pressure. http://www.titanspeed.com/content/pump/