One of these will work[ATTACH=CONFIG]533137[/ATTACH][ATTACH=CONFIG]533138[/ATTACH][ATTACH=CONFIG]533139[/ATTACH]

I ran stock melling high volume oil pump with valve spring oilers with out a problem.
High volume oil pump at 70lbs will put the same amount of oil in the top end as a low volume oil pump at 70lbs.

16 - .040" holes is only .020 sq in. That's not much flow area. Like about a single 5/32" hole.

I ran no restrictors with the valve covers in the picture. Just had some big chief valve covers done with spring oilers by blp. If some one wants me to check the orifice on my new valve covers let me know.

tim i reallly dont remember ,,i built the engine way back in 1997 and havny touched it..it does have high dollar goodies in it..i spent 6500 just on the short block...0003 sounds rite..i like to run a little loose clearances,when the engine get hot you know how sh!t can expand..

I was curious... I had issues with .003 and 55 psi that's all other factors come in play just wondered

As Mark stated earlier, you likely had something else underlying, ie bad main alignment, dirt/contamination etc. without full examination, like he said, it's purely speculation. Sucks never the less, and does make ya wonder. Mark has had a very similar setup as mentioned clearance and pressure wise, and had superb results doing so. Granted it was with a Schumann pump(they don't relieve pressure backwards through the pickup like a regular BBC pump does, and have a different relief valve circuit).

After speaking with Mark(MER Performance) I decided to go with a custom Schumann pump. Vern who owns the company is the Bob Madera of oil pumps, very intelligent and a true gentleman. Many will argue that the BBC oiling system is robust, however examine it's design and function beyond that of a grocery getter, and you will soon come to the realization this is a complete farce.

So what is the main issue with running the Melling Anti-Cavitation pump that you have found? I installed a SP/HV version on my 540. Seems I have plenty of oil volume, but the pressure is a little low for my liking by the time it goes through the external system, so I was going to put the high pressure spring in. Electronic gauge says 45 PSI hot (20 idle) at filter boss port and cheapie mechanical gauge at front oil galley port says 50 psi hot. Oil pressure maxes out at 3000 rpm and does not climb as I increase rpm. I selected the anti cav pump because I will be turning a few more RPM than most (6300 peak/6500 limiter).

Not sure about you, but i don't warm the oil in boats with a heating element on the pan, fire it up let it idle, go out through the no wake zone , and then when the oil temp starts to come up, bring it up on plane and run it. Then come off plane and idle through the harbor to your destination. Way too much time to be staring at a gauge showing 10 lbs or less oil pressure for me.
I will say that engine had tight bearing clearances, and the bearings were in very good shape.

Same here. I go easy on it until the temps start to rise, otherwise I would be idling around all day until oil temps warm up. My oil temps are not an issue whatsoever. They are in a perfect range and the thermostat works just as it should. My engine has clearances right along the lines that have been mentioned in this thread, nothing exotic or experimental. I have the motor on the stand right now and I will pull a couple caps off to see how bearings are doing when I change my pump pressure spring. Heck, for all I know I could have a faulty gauge sender. I get max of 60 psi cold on that gauge.

Here is a link for Schumann oil pumps. They have quite a few features melling does not. The most important one being an external bypass vs reverting the bled off oil backwards down the pickup. Mark Rinda uses quite a few of these pumps. He recommended I give one a try, so I bought the 140HV series. Specifically states it can be used with external coolers and spring oilers. Ships with a rated pressure of 72psi, however you can increase pressure to suite your needs with a spring/shim kit that Vern sends with the pump. Also had a provision for my Dan Olson oil pickup, and a copper gasket for the sealing surface where the pump mates to the rear main cap.


http://www.schumannsdynamicperforman...-oil-pump.html