[Make-wifi-fast] Car tire tracking

[Jonathan Morton]

> On 22 Nov, 2018, at 11:22 pm, Dave Taht <dave at taht.net> wrote:
> 
> I've gone and looked at new motors, and in comparison they seem
> impossibly fragile. I've also looked over the latest in electric
> propulsion... but I cannot imagine an electric motor at this stage of
> the game surviving 40 years in an aquatic environent. And the best
> batteries are kind of a fire hazard.

I do note that the recommended configuration for narrowboat hybrid propulsion involves old-school wet-cell lead-acid batteries (with an automatic watering system to reduce maintenance), a 10kW motor mounted well above the propshaft on a belt drive, and no fewer than *three* alternators hanging off the free end of the engine, one of which is dedicated to the starter battery circuit; the other two can recharge the main batteries while the mechanical drive pushes the boat along.  The hybrid circuit runs at 48V (so I think they're using two 24V alternators in series), and there's a mains inverter hanging off that.

One of the upsides to this setup is that there's loads of power to run standard mains-power electric appliances in the cabin, instead of weedy 12V models and/or LPG.  The projected lifetime of wet-cell batteries is about 10 years, which is better than the 3 years replacement interval recommended for gel types; they can be recycled, and their materials effectively remade into new batteries, when they do eventually go bad.

The engine itself, in the example shown, is basically a converted Kubota unit, normally associated with mini-diggers and the like.  Yes, they're still making new engines of the same basic simplicity; they meet emissions regulations by paying careful attention to the injectors, I think.  Meeting US regulations (stricter than Euro) appears to require reducing mid-range torque by a large factor, but that usually doesn't matter in a marine application.

The company apparently does seagoing versions of their engines as well as those designed for canal and river boats:
	https://betamarine.co.uk/engine-selection-for-yachts/

> I don't know if I'll rebuild this motor or not, as finding a mechanic or
> shop willing to work on it has been impossible thus far.

Fuel-oil mixing suggests worn piston rings to me, as that's the main place the two meet.  Any competent car or motorbike mechanic should be able to do something about that, without invoking a complete rebuild.  Fuel *leaks* will just involve figuring out where the leak is, and replacing either the joint or the pipe that's at fault; you may be able to do that more easily while the engine's out of the hull.

That's assuming the leak is in the supply/return system, not in the high-pressure fuel circuit of the engine itself.  I think older diesels tend to use a common-rail system instead of unit injectors, so more of the fuel system is at high pressure when running.

 - Jonathan Morton