Oil pump – M-84D (Stock Volume)   M-84DHV (Hi-Volume)

Oil pump screen – 84-DS1 (Short)    84-DS2 (Long) 

Only the by-pass pressure can be changed by changing the by-pass spring, not the idle pressure.  Some of our Melling Select Performance oil pumps offer spring options.

Oil pump pick-up screens need to be 3/8” to ½” from the bottom of the pan.

Also, see “Why replace oil pump screens?”

This is commonly caused by increased clearances within the engine, i.e., worn engine.  It could also be caused by low oil levels and by the oil pump ingesting air, or because the by-pass valve is not functioning properly.

Can be caused by using the wrong viscosity (thickness) of motor oil in your engine, or because the by-pass valve is not functioning properly.  Another common cause is tight engine clearances, i.e., new engine. Refer to your owner’s manual for the correct viscosity of oil for the climate conditions you drive in.

If a complete set is offered for your engine application, it is strongly recommended to use the complete set.

The oil pump screen could be sucking air or oil is not returning to the pan properly.  Every situation is different, because every engine, and every engine builder, is different.  These are some of the more common occurrences we experience.

No, a hi-volume oil pump is not a band-aid.

Start the engine, after it starts, check for oil pressure and bring the RPM to 1500-2000.  If the pressure is good, run the engine at this RPM range for 20 minutes.  After this run-in period, final adjustments can be made and the engine put in service.

See “Recommended Break in Procedures”

Always set your abse timing to factory specifications for the break-in period. After cam is broken in using an advance meter timing light, check your total mechanical and vacuum timing advance. Most engines can only use 34 to 38 degrees in total advance, depending on fuel and compression. Consult a local knowledgeable tuner.

If you can read the stampings on the butt of the cam (i.e. MAP Z001), call Melling Tech at (517) 787-8172 ext 134.

No, they are manufacturers marks that normally both face the same direction.

Many performance engine builders do. It is strictly a matter of choice. Some filters can create excessive resistance to the pump.

Carefully research the purchase of an oil cooler. A high quality cooler with matched lines will only create a minor flow restriction.