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Oil pressure is irrelevant. Oil pump is positive displacement usually set at 60 psig relief. Regardless if you are at 30 psig oil pressure at idle or 55 psig flowrate is the same. The heavier the oil the hotter the oil will be. Melling high vome oil pumps are about 3.25 gpm where standard volume is 3 gpm.
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I agree, as long as the oil makes it to the point of lubrication it is enough pressure. The pressure inside your main bearing reach 1000's of psig in the hydraulic wedge. In fact heavier oil usually causes less oil to get where it is needed. For example instead of flowing through the rocker arm bearings and valve stem orfice the thicker oil just overflows the rocker arm and drains into the head. Instead of the oil flowing through you roller bearings in your lifters it flows around etc.
It doesnt take much oil, look at your wheel bearings, There is zero oil circulation, only the oil in the grease lubricates for thousands of miles. Same with your alternator. You are much better off with lighter weight oil then heavier oil. Quote:
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I have had a boat engine I have been trying to kill for the last 10 years with 6 psig oil pressure at idle and 30 psig at 4800 rpm. It been that way for 900 hours in addition it was verified with a gauge. Oh, by the way it has a flat tappet hydraulic cam.
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352? 428? 427? All? Shouldn't that make a difference? For instance, the "priority main oiling" with the CSX block is more Chevy-like than Ford. |
All. The priority oiling doesn't matter; 428 or side oiler, or old 390 -- it doesn't matter. If you have the Chevy rods on your SCAT crank, still doesn't matter. If you've got double digit idling pressure and it goes immediately up when you blip the throttle then you're good to go.
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Oil pressure, oil flow, oil type will not repair or correct a bad design except for Royal Purple, they have hundres of tiny littler welders and grinders that repair surfaces.
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barry
you are so right. the wear is on the backside of the lobes, i had taken it for granted that wear would be on the front side. i'll have to look into a better set of springs for the otc afr205s. i guess i might be able to run the cam without a regrind now. interesting what you said about the synthetic oil, i had always wondered about that, especially with the flat tappet stuff. Quote:
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Stop with the synthetic sliding bologny. Every modern engine has hydraulic rollers and run with a fraction of spring pressure, ie 90 seat 200 open on some 4 cylinders, overhead cams, so when you load yours with 400lb plus open trust me nothing is sliding. We all know they all run with synthetic.
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Madmaxx i did not say anything about a standard pressure pump. You need to read again before u respond Also
Flow rate ( I am only concerned about solid roller engine in this example) Engine 1 Lets say u have a standard volume standard pressure pump and you have not adjusted the relief pressure and you also have an oil cooler with 5 feet of hose. The engine idles at 10psi with 20w50 oil in it. How much oil do u think you will get to the valve train at idle **)**) Your relief valve is dumping the oil back in the pan due to resistance in the system, and the pump my not provide enough volume when the oil is hot. Flow Rate Engine 2 Engine 2 is exactly the same except it has a HPHV pump and 10w30 oil. The oil pump and has been adjusted (Relief is set at 95psi cold oil). At operating temp the engines idles at 35psi. :D:D Which one has the higher flow rate.;) |
Hydraulic rollers are in continuous contact with the lobe, under preload - completely different situation and they'll last a bazillion miles as a result - unless you #$% up.
I do more FEs than anything else. I have some pretty decent directional data that the newer high rate cam profiles are not all that wonderful on street engines with a high ratio valvetrain - FEs are 1.76:1. It's tougher to maintain valve control as the acceleration rate increases. Milder/softer lobes are easier to deal with - lower spring pressures and/or higher RPM with a given spring. Easier on mounting hardware, and perhaps a directional lesson on solid roller selection for street use with an eye toward durability.... |
Barry, what is your opinion on using a hydraulic roller grind with solids?
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There is no need to do that since there are mild solid roller grinds out there. A solid flat tappet or solid roller needs opening ramps and closing ramps that are different than a hydraulic camshaft. Just not a good ideal.
Good luck, Keith |
pldrive
regarding flow rate, i have a crate engine 351/385 in one of the cars, and it uses -8 oil line, the pressure is read at the input on the front left side, it probably reads steady 40 lbs, less when hot. the oil is ran through the -8 lines, through an oil filter, through the oil cooler, and numerous 90 deg. bends. i don't know how this engine has survived, even hyd rollers, but it still runs fine. it is chipped to run to 6000rpm, and i haven't changed it for fear of tearing something up . |
Who cares about your bends, once again positive displacement pump as long as the pump rv not relieving (60 psig) you are getting the same flow rate just higher discharge pressure at the pump. Trust me your filter is much more restrictive than any line.
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