Gardner LW question

[Clambake]

Hello! Any Gardner LW people out there? Any idea what the purpose of this oil pressure sensor stack would be? Is it wackiness or does it make sense?
9DF8C167-F0E2-4F26-8A21-D42DD3B74407.jpg

[Hugh MacD]

I'm guessing here, but I'd think sensors for a light or two, an alarm or maybe one to an electronic gauge although the line out the top looks like it's going to a mechanical gauge. Certainly not O.E.M.

[Clambake]

I have not gotten a chance to trace them, but I assume they all go SOMEWHERE -I’m just not sure why so much redundant information about oil would be needed in a one-helm boat. Maybe a gauge, a light, an alarm, an engine room gauge -but you’d think they could all work off the same sensor (except the mechanical one)

[J. Brown]

I have not gotten a chance to trace them, but I assume they all go SOMEWHERE -I’m just not sure why so much redundant information about oil would be needed in a one-helm boat. Maybe a gauge, a light, an alarm, an engine room gauge -but you’d think they could all work off the same sensor (except the mechanical one)

No, one of the sensors will likely be a switch for an alarm light, one might be a switch for a solenoid fuel shut-off, one might be a variable resistance sensor for an electric gauge, and one is for a mechanical gauge. Makes sense to me.

[TerryLL]

I looked up the repair manual for the Gardner LW series of engines. There's nothing like that on any of the engine photos. It seems like a previous owner was completely anal about keeping tabs on the oil pressure. The bottom oil tube will certainly be better off without that mass of fittings vibrating it to death. I'd junk that mess and have a single direct feed to an analog pressure gauge using something similar to the white plastic tube at the top.

[Garret]

Top is to a mechanical gauge, top left is for a light or alarm, bottom 2 are for electric gauges.

As said, the FO really wanted to keep tabs on oil pressure!

On a boat, I prefer an electric gauge so I don't have a pipe that could pump oil all over the place if it chafed through.

[Hugh MacD]

Clambake, is that another sensor port I see coming off the oil manifold just below the lowest white sending unit? Another possibility for sensor application might be a low oil pressure engine shutdown/torque reduction system, but those are pretty obvious usually as they'll tie in with the fuel delivery system.

[Clambake]

For interest’s sake, here’s a shot of the same area from an original Marine Gardner LW brochure:
9BFA7E3C-4807-4896-8C2E-CFA67863351C.jpg

[Clambake]

On a boat, I prefer an electric gauge so I don't have a pipe that could pump oil all over the place if it chafed through.

A good 30 years ago while doing an emergency repair on my car in the dark, I unknowingly snapped a plastic oil sender pipe just like that one. Mere minutes of driving blasted the entire crankcase all over the engine compartment. Oddly enough the pressure gauge didn’t show anything wrong until it suddenly dropped to zero and I pulled over to find the mess

...might have been it was not a complete break, and the oil blasting by kept the pressure up in the pipe to the gauge until there was no more oil? I don’t know. It was an unpleasant experience.

[Clambake]

Pretty sure that’s a Pressure Gauge. Narrow Boat engines often have one there on top of the gearbox
Attachment 80563

[Slacko]

I was once on a bus that had the oil pressure sender hose let go.
Oil spraying out of the dash was enough to put me off having a non-electric guage.
My gearbox has a pressure gauge, but it is screwed onto the gearbox where I can peer at it.