batman wrote on 05/13/17 at 16:46:18:Gary_in_NJ wrote on 05/12/17 at 18:53:30:That's too low of an rpm. High idle should be around 2,000 and warm idle should be 1,400 to 1,500 rpm. Any lower and the oil pressure isn't high enough to provide adequate flow and to the cams.
Gary ,pressure when starting isn't the problem,If the rpm is 950 pressure is OK, the real problem is flow,and there is not enough flow to the bearings and parts due to the oil being cold and thick ,until the oil reaches proper running temperature ,this is why most wear occurs at starting ,not do to a lack of pressure. rev the engine when cold and you increase pressure but actually reduces flow ,a 2000 rpm idle will do the same,it will cause more friction with less lubrication .
950 rpm is not OK......even when warm - the forum recommended minimum is 1,000 rpm....1,100 is even better. The oil pump just doesn't provide enough pressure or flow at that rpm to properly lubricate the cam bearing. The Savage engine has a small brass orifice at the top of the engine case on the right side....very near the speedometer drive at the back of the oil passage case into the top of the engine case - and this orifice restricts the oil flow to the upper end during running speeds to prevent too much oil from getting to the top of the engine. At speeds below 1,000 rpm the pressure/flow just isn't high enough to get any of the oil to the top of the engine.....as least not enough to keep the cam bearings lubricated. It is imperative you keep the idle speed up above 1,000 rpm for the cam bearings to survive.
One of the reasons that I believe the most wear occurs at start up - is that when you shut the engine down the engine and oil was hot, and the hot, thin oil easily runs/drips off all the internal parts. Then when you start the engine the next time (hours, days, weeks later) - the bearings, piston and cam have a very thin layer of oil to provide the lubrication until the oil pressure/flow can get to the bearings, and also begin to be thrown around inside the crankcase to oil the piston/cylinder. Cold, thick oil can make it take longer for the bearings to get proper oil flow and accelerate the wear during "cold starts"...especially when temperatures drop really low. There are some "pre-lubers" that can be installed to pump oil through the engine prior to starting - most folks never bother with that technology as modern engines can go several hundred thousand miles being being worn out.