PatriYacht

Sounds wierd. Did your mech. tell you this? Oil pumps cannot pressurize an oil pan. Blow-by and not enough breather will cause pressure in the pan. In a new Merc black engine with fairly tight clearences, I would use a standard volume pump. For a used perf. engine with .003 on the mains and .002 on the rods, slightly worn lifter bores etc. I would use a high volume pump. Otherwise, you may have trouble building enough oil pressure. I like to have 60 at higher rpms with the engine hot and 40 at hot idle. There will be a lot of oil flying around the engine, so you also need a good deep oil pan, windage tray, scraper and kickout pan wouldn't hurt. If you can buid over 60 lbs hot with a standard volume pump, your clearences are too tight. That being said, I wouldn't pull an engine to change the oil pump if it always has more than 45 lbs hot at higher rpms.

copiercat

these motors rotating assy were assambled by world power for marine application, my builder did check clearances on one rod and main per motor, but it does have high valve cover pressures still, im running breathers and when i pull one running it seems to have a lot of pressure..

PatriYacht

The only thing you can do short of a rebuild is add larger or more breathers. The pressure is caused by combustion gasses going past the piston rings. Blower motors seem to have this problem worse. I've seen motors where the builder used screw on caps on the dipstickst to keep the oil from getting blown out

Full Force

iTrader: (5)

You can run a vacuum pump to help also.

I am pulling both of my engines tonight, to rebuild one and just check the other, i have had too may issues this year so far, I just want it to be right.

ezstriper

you were running to much oil pressure for sure..no need for it in a big block chevy, assuming that what it is, but yes your issue is crankcase pressure...is it a blower setup ? race setups run the vacume pumps and pick up h/p by reducing the pressure, you also may have to much blow by the rings as well, Rob

stevesxm

this why god gave us dry sumps. if you had a dry sump, you would have 200 % scavanging, negative crankcase pressures and perfect and adjustable oil pressure all the time. it simply staggers me the money that is spent on making big power and then you put a 45 dollar oil pump in it.... makes no sense to me. will a wet sump work ? sure... but if you are making 600 hp in abig block and doing more than cruising around with your girl friend, you should have a dry sumped motor. there is no downside to it at all.

you will spend 2 grand on a stereo and color cordinated gage bezels but an oil system that will solve every problem you will ever have is " too much money"

geeeze

Budz Motorsports

If you are blowing seals you Definitely have to much bottom end pressure not oil pressure. A good rule of thumb is that and engine needs 10 psi of oil pressure for every one thousand RPMs ex 1000 =10psi 4000=40 psi so on. This is why it is important to have a good engine builder in your camp. The complete engine must be put together as a whole package more clearance more oil hv tight clearance std hv. Lots of things go into building a good solid engine. High RPM more heat more clearance!