6V92 oil galleries

[Iceni John]

I've installed a pre-oiler pump for my bus, because the engine sometimes isn't started for several weeks or more while I'm still converting the bus.   The oil feed from the pre-oiler pump goes into 3/4" port 25 at the front of the passenger side (engine's left side) of the block, where the DDEC oil pressure sensor is also located.   Port 24 at the rear of the block on the same side has a small-diameter hose to supply a non-Detroit oil manifold fitting that's connected to the driver's and rear oil pressure gauges.   These ports are shown in the left photo on page 1 of the Detroit Service Manual  -   https://www.wanderlodgeownersgroup.com/downloads/DETROIT%2092%20SERIES%20ENGINE%20SERVICE%20MANUAL/Sect%201%20-%20Engine[1]6v92.pdf
I know these photos are for 8V92 blocks, but I'm assuming the 6V92 block's oil passages are similar.   Section 4 (Lubrication System) of that same manual isn't clear what goes where;  the drawing on its page 2 doesn't help me.

When I operate the pre-oiler pump neither the driver's nor the rear oil pressure gauges fed by port 24 show any pressure at all.   Why?   When the engine is running, both those gauges show the correct oil pressure, as does the DDEC oil pressure sensor in port 25 (I have a Pro-Link scanner).   I've temporarily connected a gauge to the pre-oiler's output, and it shows a steady 20 PSI after a few seconds.   Are ports 24 and 25 connected by a gallery?   I'm curious where the pre-oiler's oil goes after it enters port 25  -  does it only feed down to the main bearings, or does it also feed the top end of the engine?   If I connect an oil line (with a check valve) between ports 25 and 24 to feed the two gauges, will that cause problems?

To prevent oil from back-feeding through the pre-oiler while the engine is running I have a check valve after the pre-oiler pump and a NC solenoid valve before the pre-oiler pump.   All the pre-oiler's lines and fittings are 1/2", and the two valves are 3/4" to minimize flow restriction (cold 40-weight oil doesn't flow too well!).

Any ideas on this unexpected hickup with my pre-oiler project?   I want the two original oil pressure gauges to work while the pre-oiler is running, then I can operate the pre-oiler from the front if I want.

Many thanks, John

PS  -  the URL for the Detroit manual refuses to paste here correctly, so you'll need to copy and paste it separately.   Sorry!   

[luvrbus]

There  is really no need for a pre lube on the 2 cycle unless the one of the regulators on each side of the block needs replacing the oil galleys are always full they start pumping when the starter is engaged, to answer your question I have no idea what causing it unless you are trying to use the right side galley for supply you can only use the left galley for a supply entrance on the 8v92 and the 6v92 should be the same, the oil dumps back into the pan at the oil cooler the bypass valve on the cooler controls that function  good luck everything for lubing is tied to the oil gallery's   

[Iceni John]

Thanks for your reply.   I'm using only the passenger-side (i.e. engine's "left" side) for my oil connection, and that's the side also used for the DDEC pressure sensor and pressure gauges' feeds.   What confuses me is why the gauges don't see any pressure when I'm pre-oiling, but they all work fine when the engine's running.   I think I'll run a short 1/4" line from where the pre-oiler's oil now goes into the engine back to the manifold fitting for the gauges, and I'll use a check valve there to prevent any backflow.   Nothing's simple!

Most of the time I probably won't need a pre-oiler, but sometimes it's a few months between using the bus;  that's when I'm worried about the bearings' oil being squeezed out over time.   I know that a pre-oiler is usually unnecessary,  but after having my engine completely rebuilt I don't want to compromise it after long periods of inactivity.   Better safe than sorry!   Besides, it's another fun project completed.

Thanks again,
John

[luvrbus]

Thanks for your reply.   I'm using only the passenger-side (i.e. engine's "left" side) for my oil connection, and that's the side also used for the DDEC pressure sensor and pressure gauges' feeds.   What confuses me is why the gauges don't see any pressure when I'm pre-oiling, but they all work fine when the engine's running.   I think I'll run a short 1/4" line from where the pre-oiler's oil now goes into the engine back to the manifold fitting for the gauges, and I'll use a check valve there to prevent any backflow.   Nothing's simple!

Most of the time I probably won't need a pre-oiler, but sometimes it's a few months between using the bus;  that's when I'm worried about the bearings' oil being squeezed out over time.   I know that a pre-oiler is usually unnecessary,  but after having my engine completely rebuilt I don't want to compromise it after long periods of inactivity.   Better safe than sorry!   Besides, it's another fun project completed.

Thanks again,
John

The film oil  leaves on the rod and main bearing is amazing stuff, I did some work on old army tanks they hired me to disable some for Vet centers and rest areas, I would drain the oil over a couple of days and start the 2 cycle lol some of those would run for 15 minutes before they seized up on the average they would run at least 5 minutes, I would be in tears doing that but they wanted the engine left complete, who knows why