"Hairbrained" Water Heater

[roverrescue]

So the engine is out of the 130 at the moment.
Doing a little thinking which is always dangerous.

I vaguely remember someone talking about this concept a whiles ago on AULRO but anyway Ill float it again and see what people think.

-Replace existing washer bottle with a larger aluminium tank (10L or so)
-maintain small washer pump at bottom for the windscreen
-plumb the tank such that from the bottom of tank small diameter copper pipe runs down and back then spirals around the exhaust - runs around and up tighter and tighter until it gets to the turbo flange where it then runs back into the top of the tank.
-Just like a solar water heater the water in the tank should thermo symphon and heat as you drive - perhaps put a pressure relief cap (ala radiator cap) on top for safety.

-Obviously dont want to remove too much heat from the exhaust and reduce its scavenge efficiency but other than that I cant see toooo many dramas.

-Once at camp have a drain on the tank drop it into the shower bucket, add cold if needed and voila!


Just how hairbrained is the thinking?

PS I intend to wrap the exhaust with fibreglass exhaust wrap too to try keep heat loading down in the cab

Steve

[Basil135]

The theory is sound.

However.....

This means you couldn't use Rainx or similar, but if that doesn't bother you, then why not...

You never know, it might even get warm enough to make a cuppa from as well :D

[slug_burner]

how is the washer pump going to go in hot water?

you will need some flexible hose to allow for the relative movement between engine/exhaust and your tank.

it will work, how well will depend on how much pipe you wrap around the exhaust.

[Blknight.aus]

correct. done it with a stand a lone bottle. (get one of the bladder bag washers to replace the OEM tank from a disco)

you need to use 3/8th copper and run at less than 30 degrees to perpendicular other wise the turns are too tight around the pipe and its gets prone to kinking while you're installing it. I got 3 turns in on the vertical part of a series exhaust and on a long enough drive it would boil the water off.

One other thing Id do differently for the heater pipe when I do it again is to physically bend the bottom of the feed pipe back up towards the bottle to save stress on the hoses

The only other issue Ive had is with vibration abrading one metal against the other, ID suggest having a crack with stainless pipe for the coil and silver soldering, brazing or even tack welding the 2 at 120ish degree points round the exhaust. (my solution to keeping the pipe on was to run it up between the manifolds and thread it over between the manifolds.)

revising my original tank concept (which was originally a pair of half inch spigots drilled into the top of the tank that allowed me to hook up to the roof rack PVC pipe tank for extra capacity)

Id set the plumbing up like a donkey heater so that your outlet and inlet are both at the top of the tank with the outlet drawing from the top of the tank and the inlet run to the bottom of the tank. water in equals water out.
Use a 1/2 inch outlet and about 3 feet of 1/2inch outlet hose then for the inlet put on a 2 inch to 3/4 inch reducer, drill a 3/4hole in the side of the reducer and get a 2 inch cap. When your not using it simply route the hose through the hole you made in the side of the reducer and poke it into the hole and put the cap back on. to get water out simply feed the hose out through the wheel well area and pour water into the top of the reducer (remove the cap first) if youve gotten the right size reducer most roundish 2l bottles will happily stand in it and gravity feed in and if you need to fill from a bucket youve got a built in funnel.

2l of 80 degree water mixed into 5-6l of room temp water makes for a tepid shower

have fun and thanks for adding another project to try and squeeze into the SWMBOS disco.