Piston oil jet size
- Thread starter wilks3
- Start date
Here is what my book says (3-10, Bottom End):
"The piston jets (N29), which receive a supply of oil from the intake lifter bores, spray the underside of the piston for cooling of the piston crown and skirt area. A check valve in each jet opens only when the oil pressure reaches 12-15 psi, at which point the engine is operating above the idle speed. At idle speeds (9-12 psi), the valve remains closed to prevent over oiling and to ensure proper system operating pressure."
No specs on the orifice size of the jets. But the part number is 22307-99 (maybe an up-dated suffix now). You might want to wander by a Dealership and look at one and even measure the orifice.
TQ
"The piston jets (N29), which receive a supply of oil from the intake lifter bores, spray the underside of the piston for cooling of the piston crown and skirt area. A check valve in each jet opens only when the oil pressure reaches 12-15 psi, at which point the engine is operating above the idle speed. At idle speeds (9-12 psi), the valve remains closed to prevent over oiling and to ensure proper system operating pressure."
No specs on the orifice size of the jets. But the part number is 22307-99 (maybe an up-dated suffix now). You might want to wander by a Dealership and look at one and even measure the orifice.
TQ
1/64th of a inch is equal to 615 microns.
So by this measurement a filter that can filter down to 5 microns must be something.
I can't see a oil jets inside diameter being smaller than 1/64th (615 microns) of a inch and doing a good job spraying bottom of pistons.
I wish some good natured HD mechanic would answer this question.
So by this measurement a filter that can filter down to 5 microns must be something.
I can't see a oil jets inside diameter being smaller than 1/64th (615 microns) of a inch and doing a good job spraying bottom of pistons.
I wish some good natured HD mechanic would answer this question.
Hoople
Account Removed
Your asking for a very specific piece of information. It is so specific, it is not readily published. Who is going to know that specific value off the top of their head except from a person like yourself who really wants to know the answer and researches it out. Of the 3 questions you asked, on 2 of them you received a direct answer. On the 3rd you received enough information from TQ to build from it. I would take a ride to the dealer, look at a lifter and measure it for the specific decimal value you are looking for.
Then once I knew that value, I would come back and share it with the rest of us so we all know. I thought that is how it works.
Micron = 0.000039 in.
So 5 microns is 0.000195 in.
I don't think the spec on the filter is strickly for the orifice on the jet of the piston sprayer. But I have never seen one of these things, so I don't know what it looks like at the spray tip. Pix anyone?
TQ
So 5 microns is 0.000195 in.
I don't think the spec on the filter is strickly for the orifice on the jet of the piston sprayer. But I have never seen one of these things, so I don't know what it looks like at the spray tip. Pix anyone?
TQ
Chopper
Senior Member
Here's the pic's out of service manual. The Twin Cams have had piston jets for cooling since 99, I think, so the 10 micron filters were used then, I think the camplate having more passages and possibly some after thoughs on the piston jets lead to the 5 micron filter?
