Do we need to occasionally run the Pentastar at wide open throttle for lubrication purposes?

[Hootbro]

Is the internet big enough for @ShadowsPapa big head to fit in?

Sponsored

 

[ShadowsPapa]

Do you really think the squirters would be fed right off the main galley though? Path of least resistance dictates if you have one VERY VERY IMPORTANT thing that has resistance to flow(i.e. main bearings, top end) and one ancillary thing that has no resistance (i.e. squirters) wouldn't you have to have some sort of a separate feed, or a PRV or something preventing all your oil from spraying the underside of the pistons and leaving the bearings dry? I get you don't need a huge amount of oil there but you need some, you can't just turn on an open tap elsewhere on the same galley and cross your fingers.

That's why the squirter cutoff made so much sense to me. You have either a separate feed, or a PRV / reed valve that is set to, say, 50psi, that blocks them off, and that PRV would also create backpressure in the galley that kept the important bits slippery after they opened too. 3K, pump ramps up, PRV opens, squirter port opens, PRV maintains backpressure on main feed, everyone is happy.

Prior designs, this was handled by openings in the rods that lined up with the crankshaft gallery - when the hole in the rod lined up with the hole in the crankshaft's rod journal, oil was shot directly at the opposing piston bottom. It happened all the time, regardless of RPM.
Since these are "Squirters", I can see it being open at all times, little loss. Think of the much lower volume oil pumps of the past where oil fed through the lifters up through the push rods, up through holes in the rocker arms to lubricate the rockers and valve stems. It was a controlled "leak".
With enough volume, yeah, I can see those being open all the time. It's a spray nozzle as opposed to the open holes of old where oil came out even at 700 RPM.
I'm not saying there's no control at all, just can imagine it's not necessarily necessary, depending on the amount of controlled leakage.

 

[ShadowsPapa]

Is the internet big enough for @ShadowsPapa big head to fit in?

Doubtful.........

 

[Charles 236]

The piston oil jets have a spring loaded check valve, I seem to remember that it requires about 15 psi to open, allowing oil to spray. These Pentastar engines use a very high volume oil pump, but only need high volume and pressure at higher RPMs, hence the solenoid to switch modes.

 

[ShadowsPapa]

The piston oil jets have a spring loaded check valve, I seem to remember that it requires about 15 psi to open, allowing oil to spray. These Pentastar engines use a very high volume oil pump, but only need high volume and pressure at higher RPMs, hence the solenoid to switch modes.

That's the thing - these oil pumps move a crazy amount of volume compared to older gear pump designs.
The check valve is likely to force oil to travel to the upper ends and more critical areas before allowing the "leakage" to begin. If you watch the OP while these start cold, it's very very fast.
The amount of volume these pumps provide is pretty high.
By the time you have 15 psi built up, it's been running maybe 2 seconds and oil will be getting to the top end.
Think of what the old gear pumps provided on V8 engines with all of that oil going up the push rods, running over the rockers, and shooting out the holes in the rods toward the pistons, and yet those old gear pumps with a fraction of the volume still kept up.

 

[Cburd61]

I had a 3 speed oil pump once. It was a crash box, like an old VW bug. Real pain to get into gear, and you didn’t dare down shift.

Sponsored