Tweet
Re: Oil Pressure question
Little bit of misconception. The orifice in the oil line is NOT to act as a snubber for the gage. It is there so that all the oil will not blow out of the engine if the line ruptures. The pressure to the gage will read right whatever the line size is since the oil is incompressible. It is only when the fluid is FLOWING that the size of the line matters.
That is the THEORY, in the real world a very small line can get clogged easier and that is why they put an orifice in instead of just using a very thin (easy to route) line. The orifice should be at the engine end, usually in the fitting that screws into the engine. Just a tiny piece of crud in the hole and the gage won't work right. By the same token, my LINE had some sludge in it too, and the gage was spastic till I flushed it out. Be REAL careful putting the gage end of the line in a jar and running the engine. If there ISN'T an orifice at the engine you are going to need a bath before the wife lets you back in the house and even if new carpet is easy to install, it costs a lot. Better to just pull the prop through to check it or do what I did and pull the line and fittings and blow them out with shop air. When I put the lines back in I primed them with lighter oil since the oil in the line never actually moves, it just transfers the pressure. Bleeding the line with the light oil was a lot easier and less mess.
Hank
Little bit of misconception. The orifice in the oil line is NOT to act as a snubber for the gage. It is there so that all the oil will not blow out of the engine if the line ruptures. The pressure to the gage will read right whatever the line size is since the oil is incompressible. It is only when the fluid is FLOWING that the size of the line matters.
That is the THEORY, in the real world a very small line can get clogged easier and that is why they put an orifice in instead of just using a very thin (easy to route) line. The orifice should be at the engine end, usually in the fitting that screws into the engine. Just a tiny piece of crud in the hole and the gage won't work right. By the same token, my LINE had some sludge in it too, and the gage was spastic till I flushed it out. Be REAL careful putting the gage end of the line in a jar and running the engine. If there ISN'T an orifice at the engine you are going to need a bath before the wife lets you back in the house and even if new carpet is easy to install, it costs a lot. Better to just pull the prop through to check it or do what I did and pull the line and fittings and blow them out with shop air. When I put the lines back in I primed them with lighter oil since the oil in the line never actually moves, it just transfers the pressure. Bleeding the line with the light oil was a lot easier and less mess.
Hank
Comment