Ron,
Sorry, I missed the distinction between the pressure relief and filter bypass.....As long as there IS a filter bypass somewhere in the system all should work, shouldnt it? If we are doing oil changes at fiarly frequent intervals we shouldnt get the filter bypass activating , shouldnt we?
Is there any reason a P6B pump cover wont fit an SD1 timing cover????
No worries JP. The filters that fit the P6B oil pump front cover do not have filter bypass valves, as the valve is within the front cover. The frequency of oil changes and the bypass valve activating are not always connected. The relationship between the bypass valve and filter is a binary comparative function. When the engine is cold or in cold weather, if the force required to push the oil through the filter is greater than the force required to open the bypass valve, then the oil will circulate without going through the filter, so the engine will receive unfiltered oil. When the viscosity of the oil begins to decrease through increasing temperature and the force to open the bypass valve is then less than required to push oil though the filter, the bypass value will remain closed and the engine will receive filtered oil. On engines that do not receive regular oil and filter changes, the potential for increased resistance within the filter due to accumulation of particulate matter is very real. In this circumstance, the probability of the engine receiving unfiltered oil on a more regular basis cannot be dismissed.
The P6B oil pump front cover will bolt straight up to an SD1 timing cover, or indeed any of the later covers that do not have a crankshaft driven oil pump. The footprint is exactly the same, so you have no worries there. I have an SD1 timing cover on my 4.6 running with a P6B oil pump front cover.
Ron.