Clutch for Engine Driven Bilge Pump

[redbopeep]

Hey guys, rooting through my stuff looking at everything the previous owner of our boat had bought, I found an engine-driven bilge pump. Needs a new sheave and I'd like to put together the sort which has a clutch...don't know where to start with that, though. The pump is Oberdorfer pump 6658. There are, with the pump, two extra rubber impellers and a rebuild kit (which includes an impeller) for the oberdorfer pump 402M--which looks like the same pump when I looked it up online to get the specs/rpm, etc.

Anyone know the best/easiest way to put this together with a clutch for the sheave?

Thanks!

[Ross M]

I seem to recall reading that older Cadillac a/c compressor clutches were the hot ticket for this.

Ross

[The Bigfella]

Yeah, I was trying to track down a new clutch a few years back and the cost was ridiculous - until someone gave me a car air conditioning compressor.

[Rob Stokes, N. Vancouver]

Automotive A/C compressors may (probably?) may be set up for a tapered shaft and the pump shaft is almost guaranteed to be straight, keyed and a different diameter. When you find a good used automotive clutch, take it to a machine shop, along with the pump and have them mill the clutch to fit the pump shaft.

If the pump is large, you may want to source a used electric clutch from a wrecking yard that deals with large semi-sized transport trucks. Some use similar clutches for their air compressors, and these are a much larger and stronger clutch (when compared to an automotive A/C clutch).

These type of clutches work quite well - I used to use on on a big washdown pump on a commercial boat. I also used one on a back-up hydraulic pump and even though it was barely enough, it got me out of a few scrapes when needed. Make sure you have a good 12VDC (or maybe 24VDC on the larger one? not sure..) source to the clutch though, as the electro magnet doesn't draw a lot of power, but it needs enough else it will slip and glaze. If/when that happens, it's time for a new clutch.

Rob

[Canoeyawl]

If this is truly an emergency set-up you will be well advised to stay away from all electrical devices. It is only an inconvenience if your air conditioner doesn’t work but if your standby pump doesn’t work it could be a disaster. The most reliable clutches are mechanically operated.
I have seen simple sliding pump mounts that tighten or loosen the driving belts that work well.
Twin Disc probably makes a front driven pto mount with a clutch for your engine and application, but they are very expensive.