pamcopete
Ride.Enjoy.Life is Simple
hein,
You would not experience a clogged oil filter just because you were late changing the oil. There would have to be an accumulation of foreign material to clog the filter. When the bypass opens, the "dirty" oil is then allowed passage into the engine where it can cause damage.
Predictable failures, such as the disintegration of the timing chain guide, can create a mass of debris in the oil, which gets past the sump filter because all sump filters have a hole in them. The bypass opens and lets this junk into the more delicate parts of the engine, or it simply causes oil passage blockage which would require you to tear down the engine to cure.
By eliminating the by pass valve, you eliminate this possibility, but it is essential that you then install an oil pressure gage so you can monitor the pressure in the absence of the bypass valve.
The early XS650's had the bypass installed in the oil pump itself which precluded allowing the dirty oil to re enter the engine. A much better arrangement and one that matches my opinion on both the purpose and function of the bypass valve. I presume that Yamaha in it's wisdom eliminated the valve on the pump and moved it to the oil screen as a cost saving measure.
Having the oil pressure bypass installed as part of the pump, venting to the crankcase, made this arrangement more of a true pressure regulator because it was vented to essentially a zero pressure area, whereas the current arrangement vents to the engine oil galley, which would still produce some back pressure, limiting the effectiveness of the by pass to regulate the pressure below the inherent pressure in the oil galley.
Normally, one expects an engineer to be detailed in their assertions. So, when you say that:
"This is just not right! Its primary purpose is not to regulate the oil pressure at any time!"
It sounds more like an opinion rather than a factual statement that can be backed up by perhaps some numbers, like
1. What is the maximum differential pressure that the oil screen can withstand without failing?
2. What is the maximum pressure that the oil pump can produce before damage occurs?
3. What is the maximum negative pressure that the sump screen can withstand before it develops a hole?
4. What, in your opinion, is the main cause of a hole developing in the sump screen if it is not excessive low pressure and flow during the cold engine operation?
5. If there is a number to answer all of the above, then how do you regulate the pressure so those numbers are not exceeded?
6. Why did Yamaha initially build the oil pressure relief valve into the oil pump and not the oil screen?
7. Why did Yamaha move the valve to the screen?
I don't know if you have a spell checker or not, but a good and FREE one is available from: http://www.iespell.com/
And, welcome to the club!
You would not experience a clogged oil filter just because you were late changing the oil. There would have to be an accumulation of foreign material to clog the filter. When the bypass opens, the "dirty" oil is then allowed passage into the engine where it can cause damage.
Predictable failures, such as the disintegration of the timing chain guide, can create a mass of debris in the oil, which gets past the sump filter because all sump filters have a hole in them. The bypass opens and lets this junk into the more delicate parts of the engine, or it simply causes oil passage blockage which would require you to tear down the engine to cure.
By eliminating the by pass valve, you eliminate this possibility, but it is essential that you then install an oil pressure gage so you can monitor the pressure in the absence of the bypass valve.
The early XS650's had the bypass installed in the oil pump itself which precluded allowing the dirty oil to re enter the engine. A much better arrangement and one that matches my opinion on both the purpose and function of the bypass valve. I presume that Yamaha in it's wisdom eliminated the valve on the pump and moved it to the oil screen as a cost saving measure.
Having the oil pressure bypass installed as part of the pump, venting to the crankcase, made this arrangement more of a true pressure regulator because it was vented to essentially a zero pressure area, whereas the current arrangement vents to the engine oil galley, which would still produce some back pressure, limiting the effectiveness of the by pass to regulate the pressure below the inherent pressure in the oil galley.
Normally, one expects an engineer to be detailed in their assertions. So, when you say that:
"This is just not right! Its primary purpose is not to regulate the oil pressure at any time!"
It sounds more like an opinion rather than a factual statement that can be backed up by perhaps some numbers, like
1. What is the maximum differential pressure that the oil screen can withstand without failing?
2. What is the maximum pressure that the oil pump can produce before damage occurs?
3. What is the maximum negative pressure that the sump screen can withstand before it develops a hole?
4. What, in your opinion, is the main cause of a hole developing in the sump screen if it is not excessive low pressure and flow during the cold engine operation?
5. If there is a number to answer all of the above, then how do you regulate the pressure so those numbers are not exceeded?
6. Why did Yamaha initially build the oil pressure relief valve into the oil pump and not the oil screen?
7. Why did Yamaha move the valve to the screen?
I don't know if you have a spell checker or not, but a good and FREE one is available from: http://www.iespell.com/
And, welcome to the club!
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