RV8 oil pressure and pressure relief valve setting.
Posted: Sun Jan 06, 2008 2:24 am
My 1974 Rover 3500 P6B when fitted with the original 3.5 litre V8, coolant temperature of approx 80 degrees, 74 degree thermostat fitted, engine speed 2500 rpm, oil pressure was typically around 40psi. At 3000rpm 45psi.
Prior to replacement at 205,000 Miles, at 3000rpm oil pressure was around 35psi. Engine oil was always Pennzoil GT performance 20W-50, changed every 2000 to 2500 miles along with the filter, Pennzoil PZ-2.
My new engine is a 4.6 litre thor engine, fully top hat linered, new bearings throughout, all new top end with high torque camshaft, sd1 timing cover along with the latter oil pump gears, brand new P6 oil pump front cover, 13 row engine oil cooler fitted, sandwich plate between oil pump cover and oil filter. Coolant thermostat 74 degrees. The engine has now covered some 7500 miles since new, engine oil is Penrite HPR30 20W-60 changed every 1000 miles along with the filter Pennzoil PZ-2.
At idle, 600rpm, coolant temperture of approx 80 degrees with 80 to 90 degrees showing on the oil temperature gauge (sender in the sump plug), oil pressure is 30psi. At 2000rpm, 45 to 50psi, at 2500rpm 50 to 55psi. These figures have remained unchanged since the engine was built and fitted.
I have used both the original "Smiths" oil pressure transmitter and the correct new replacement, with both senders registering essentially the same oil pressure on the gauge.
These are great figures, but I am rather curious as I cannot find a definite answer to....What is the specified "blow off" pressure of the pressure relief valve within the P6 oil pump front cover?
According to one of my workshop manuals for the P6, the oil pressure figures quoted are 30 to 40 psi at 2400rpm and 55psi at 4000rpm.
Thermostat settings are given as 78 to 82 degrees C.
If the oil pressure relief valve operates, what happens to the indicated pressure on the gauge at that time? Is the oil still filtered on bypass or does the engine then utilise unfiltered oil until the oil pressure is reduced and the relief valve returns to the closed position?
In appreciation,
Ron.
Prior to replacement at 205,000 Miles, at 3000rpm oil pressure was around 35psi. Engine oil was always Pennzoil GT performance 20W-50, changed every 2000 to 2500 miles along with the filter, Pennzoil PZ-2.
My new engine is a 4.6 litre thor engine, fully top hat linered, new bearings throughout, all new top end with high torque camshaft, sd1 timing cover along with the latter oil pump gears, brand new P6 oil pump front cover, 13 row engine oil cooler fitted, sandwich plate between oil pump cover and oil filter. Coolant thermostat 74 degrees. The engine has now covered some 7500 miles since new, engine oil is Penrite HPR30 20W-60 changed every 1000 miles along with the filter Pennzoil PZ-2.
At idle, 600rpm, coolant temperture of approx 80 degrees with 80 to 90 degrees showing on the oil temperature gauge (sender in the sump plug), oil pressure is 30psi. At 2000rpm, 45 to 50psi, at 2500rpm 50 to 55psi. These figures have remained unchanged since the engine was built and fitted.
I have used both the original "Smiths" oil pressure transmitter and the correct new replacement, with both senders registering essentially the same oil pressure on the gauge.
These are great figures, but I am rather curious as I cannot find a definite answer to....What is the specified "blow off" pressure of the pressure relief valve within the P6 oil pump front cover?
According to one of my workshop manuals for the P6, the oil pressure figures quoted are 30 to 40 psi at 2400rpm and 55psi at 4000rpm.
Thermostat settings are given as 78 to 82 degrees C.
If the oil pressure relief valve operates, what happens to the indicated pressure on the gauge at that time? Is the oil still filtered on bypass or does the engine then utilise unfiltered oil until the oil pressure is reduced and the relief valve returns to the closed position?
In appreciation,
Ron.