Until I found this board it was my understanding that a filter bypass valve would never open on any well maintained engine.
The engines I work on a bypassed filter is a bad thing. there are differential pressure switches on both the fuel and oil filters that will alert the operator just prior to bypass opening. from school I remember even on the recip engines the bypass was only for a clogged filter.
What makes automotive so different? My guess is poor maintenance, many cars do not see regular oil and filter changes. dirty oil is better than no oil, seams to me that if the bypass valve is opening with a clean filter then it is to small for the amount of oil the pump is trying to push through it. The auto manufacturers are guilty here. having a Chevy with lots of ground clearance I am fortunate enough to have my pick of 1pt pf454 through 2 qt pf932 filters, if it does bypass or getting close to it I would like to know about it and take the proper action like wait a little longer on warm up or if it is a constant problem change filters
So i am thinking of doing a little experiment, found a part # for a 30psi bypass that fits Chevy big blocks like mine:
“Gen V and Gen VI big-block crate engines come with two oil pressure bypass valves installed in the engine blocks. Both of these valves are rated at 11 psi pressure differential. One valve is for the oil filter and the other is for the production oil cooler. If you install an aftermarket oil cooler or remote oil filter that attaches to the oil filter pad on the engine block, you should be aware that you need to change the oil filter bypass valve in the engine block. The aftermarket oil lines add resistance which will cause the bypass valve to bypass the aftermarket oil cooler and/or oil filter all the time. Obviously, if the cooler and filter are bypassed the oil will be dirty and hot. Your engine could run hotter and could be damaged by dirt in the oil. If you choose to use an aftermarket cooler or remote oil filter that attaches to the pad, you should change the bypass valve to one with a higher differential pressure rating. A good choice would be GM# 25161284 which is rated at 30 psi. Remove the valve that is closest to the crankshaft and replace it with the new valve. Press the new valve into the engine block and stake it in three places. You should note that the bypass valves don't need to be changed if you use a production oil cooler which uses the production holes in the engine block and you don't use a remote oil filter. Also, if you use an adapter that just angles the filter for clearance you don't need to change the bypass valves”
I ordered one from Gmpartsdirect.com for $2.98 looks like a quality valve (more than I was expecting), should I give it a try? I am currently running an over sized filter with wire mesh backed synthetic media 30psi should not be a problem for it, I watch my oil pressure quite regularly especialy on start withc is where thi swill show itself the most
[ October 25, 2003, 04:50 PM: Message edited by: RavenTai ]
The engines I work on a bypassed filter is a bad thing. there are differential pressure switches on both the fuel and oil filters that will alert the operator just prior to bypass opening. from school I remember even on the recip engines the bypass was only for a clogged filter.
What makes automotive so different? My guess is poor maintenance, many cars do not see regular oil and filter changes. dirty oil is better than no oil, seams to me that if the bypass valve is opening with a clean filter then it is to small for the amount of oil the pump is trying to push through it. The auto manufacturers are guilty here. having a Chevy with lots of ground clearance I am fortunate enough to have my pick of 1pt pf454 through 2 qt pf932 filters, if it does bypass or getting close to it I would like to know about it and take the proper action like wait a little longer on warm up or if it is a constant problem change filters
So i am thinking of doing a little experiment, found a part # for a 30psi bypass that fits Chevy big blocks like mine:
“Gen V and Gen VI big-block crate engines come with two oil pressure bypass valves installed in the engine blocks. Both of these valves are rated at 11 psi pressure differential. One valve is for the oil filter and the other is for the production oil cooler. If you install an aftermarket oil cooler or remote oil filter that attaches to the oil filter pad on the engine block, you should be aware that you need to change the oil filter bypass valve in the engine block. The aftermarket oil lines add resistance which will cause the bypass valve to bypass the aftermarket oil cooler and/or oil filter all the time. Obviously, if the cooler and filter are bypassed the oil will be dirty and hot. Your engine could run hotter and could be damaged by dirt in the oil. If you choose to use an aftermarket cooler or remote oil filter that attaches to the pad, you should change the bypass valve to one with a higher differential pressure rating. A good choice would be GM# 25161284 which is rated at 30 psi. Remove the valve that is closest to the crankshaft and replace it with the new valve. Press the new valve into the engine block and stake it in three places. You should note that the bypass valves don't need to be changed if you use a production oil cooler which uses the production holes in the engine block and you don't use a remote oil filter. Also, if you use an adapter that just angles the filter for clearance you don't need to change the bypass valves”
I ordered one from Gmpartsdirect.com for $2.98 looks like a quality valve (more than I was expecting), should I give it a try? I am currently running an over sized filter with wire mesh backed synthetic media 30psi should not be a problem for it, I watch my oil pressure quite regularly especialy on start withc is where thi swill show itself the most
[ October 25, 2003, 04:50 PM: Message edited by: RavenTai ]
