I have had an EJ22 in our bus for years now, but no heater yet.

The physical placement, ducting, cabling etc is easy stuff, I will make all that. The main question I need technical support on is the actual tap.

I understand the two heater pipes on the EJ22 engine must maintain a flow when the heater is off as part of the thermostat bypass. I have a bit of hose doing that now. The tap required?

Would it be a tap like a VN, VR, VS, VT Commodore with the 4 way openings that would have two to the engine and two to the heater, allowing bypass when off and full loop flow when on?

This type of tap is available new with electric actuation, cable actuation or vacuum like the Commodore.

Hi

Good question. I think the 4 way tap like the Coomodres use would work.

I have a 3 way tap from an old Holden Kingswood I think. Im not upto that stage as yet but I think it will work OK.

Steve

I have a heater matrix mounted under the floor upfront and hooked into the vent up pipe. I don't use a bypass tap and the core has water passing through it at all times. The blower on/off and the vanes control heat to the cab. Once the system is bled of air it works fine.

Brendan

an early toyota landcruser / larger coaster bus has a very good heater set up in the rear. These are very compact not like the subaru set up ! I purchsed my coaster bus heater from a place that kits the busses out for the mines $50.00 .

Same as Brendan for me although I'm running a H made up of coppe plumbing fittings under the rear seat

Donk
H
Matrix

The horizontal part of the "H" is an isolator valve so I can have all the flow to the heater or 50:50 it.
My matrix is from an Alfa and can be shut down but I haven't needed to.

A Mk1 Golf (apparently) or T3 Caravelle (rear) matrix unit is very compact with the blower and sits under the rear seat very nicely BTW

If you can't be bothered wiring a switch use a central heating room thermostat to the motor via a relay - job's a good un.

(hey Brendan, where you been? Need photos)

There is a fellow in Canada that has created a spacer that allows the use of a heater without making the thermostat go nuts from the larger volume of coolant in the heater loop.



The heater loop goes to the regular nipple on the water pump while the 1/2 inch nipple connects to a line run directly from the coolant outlet manifold. That way the thermostat sees only the temperature directly from the engine.

http://www.subaruvanagon.com/tom/Thermostat%20housingk.htm 

One caution: Always use a genuine Subaru thermostat. Aftermarket thermostats may not have a wax pellet housing long enough to be in the flow from the outlet manifold.

Unless the heater becomes uncomfortably warm you really don't need a valve. Just turn the fan on when you want heat, off when you don't.

When I spoke to Tom he said he's supplied some of these to Oz for people utilising clorifiers(sp? the water heater thingies).

Yeah a lot of jap cars run the coolant through the heater all the time and it's regulated by flaps in the heater box as to whether the air goes through it or not. I intend to run mine constantly through and just control heat by the fan speed. But no dramas in the heater tap, as long as there is coolant flow in and out of the heater pipes to the engine at all times.

The problem with bus heaters seems to be that they extract a lot of heat and can significantly lower the temperature of the circulating coolant, unlike the stock Subaru heater. This keeps the thermostat too cool and might allow it to behave in erratic ways.

The Tom Shiels thermostat spacer ensures that the thermostat always sees the true engine temperature. A good bit of insurance, IMO.

Hi

I would prefer to keep hot coolant away from the inside of my car (heater core) and only bring it in when I need it.

Steve

With a 1975 bus you wont need hot coolant in the vehicle. There is enough room under the floor at the front, in the gap where the front belly pan is to allow fitting a heater core. The constant heat core is outside the vehicle, but inside a covered area, and the heater can be fitted to the original vent tubes that run up the nose of the bus, allowing original foot heating vent and demister vent.

I like the idea of not needing an actual tap, and using the fan to make heat travel inside the bus or not.

The thermostat spacer makes so much sense. I had a look at his website. It is amazing to think that it is busses are overheating in winter without the thermostat bypass unit he makes. The heater cools the water so much in winter that it keeps the thermostat closed. His unit makes the thermostat operate off coolant manifold temperature.

I like this discussion it is very helpful.

Would it be wise to fit a Davies Craig electric heater pump. 5/8 inlet and outlet electric coolant pump to make stronger water flow for heaters

For what it's worth, my cut down heater matrix. Fits below the floor and hooks in to the original up pipe. I have a cut down Kombi blower fan behind it. One of the old heater control cables for the blockoff vane and the blower is trigered by a limit switch on one of the heater control levers behind the dash panel. Looks stock and works toasty.


In response to George's comments, I do not bypass and on the highway with the front vents open and the heater flap open my temp creeps up from normal operating to +15deg C

Brendan

Hi

In my bug I had a Troopy unit mounted under the rear seat, opposite the battery, that's why I didn't want heat in the unit when not in use.

I just had a thought, looking at WBX heater circuit, it takes hot water from the engine outlet pipe and returns it into the radiator return pipe just before the thermostat, why not leave the Subaru pipes looped as they are and take the heater feed and return like the WBX do?

Steve

I like the idea of using the stock vents. In fact, if you still have the stock heat ducting you could use the rear vents as inlets and recirculate the cabin air simply by inserting the heater core and blower somewhere in the loop.

Keeping the heater core under the bus also reduces air trapping issues.

So far I have decided I will run the heater core/ fan assy under the front floor above the belly pan. I will have it connected full time to the engine in the heater loop with no tap. I will draw all or 75% air from the rear vents that are at the back of the walk through, and connect the heated air into the original front vent system, foot and demist.

The cooling effect of the entire heater loop and it's effect on the thermostat is one thing that concerns me. It sound strange to have a car that overheats only in winter, but it makes sense that the cooled water from the heater loop will keep the thermostat closed in an erratic way.

Should I fit a Davies Craig 5/8 electric booster pump, it can be set to ignition power and be on all the time to keep the heater loop flowing well, or set to the heater fan to give good flow when the heater is needed to heat.

As long as I have hot water and power I can fabricate the heater core, fan, cable, boost, whateva. I do this stuff no problem. It is just the technical intricacies of the heater/ thermostat bypass and loop that I need to know the physics and dimensional information so I can see how I can make an eclectic decision on setting up the heater.

I am now at the same point coming into winter in Sydney..... I need some heat.
I plan on setting something up the same as Hellbus mentioned here....... and I have the same worries re: the overcooling effect of the heatre core.
Reading threads from th eUK guys seems to indicate it would not be a worry unless your talking sub temps?
Did you ever get this sorted Hellbus.
I have been playing with the idea of taking a feed from, and returning to, the radiator that sits under the bus.
I realise that I would not have heat on tap and would have to wait for the whole system to come up to temp for good heating???
alex

Run your matrix under the back seat (subject to your local "demisting" rules) , add in the "bypass valve" that I've posted here. Watch your gauge... then please post results.

There's been a fair few requests from the Aussies on here, but no answers for the buses!

POP to make a bypass & cheap as chips

Share the results please

I got the bus engineered, and there was no requirement to actually heat the demister. You are allowed to have a cold air demister. Two speed fan, and air coming from fresh outside.

So I will put an aftermarket matrix under the back seat. Cheap, new, big and warm.

I'm in the process of adding a heater to mine.
Im using a festiva heater core in a home made enclosure but the mob I'm buying my A/C bits off sell a variety of aftermarket heater cores with fans like this

driving to Gunnedah a few weeks ago -1 out side the vw inside my vw a nice 11 deg what heater
a joel

hmmm i seem to remember the heat off your radiator blasting through the radio hole and glovebox keeping the inside warm last year coming back from dorrigo look out

That is exactly the matrix I ordered late last week... should be here tomorrow.
My plan now is...
That matrix with a few easy mods will sit under the front floor inside the bash plate area. it will take air from the vent that sits at the rear of the walkthrough and blow up into the cabin thru the front vent system.....giving me either toasty toes or demisting the windscreen.
The matix will get a constant water feed with heat controlled by the fan speed.
I will feed it hot water from the ej22 heater pipe out of the top manifold...and return it alongside the radiator hose and to the base of the waterpump/thermostat.
Will keep a bypass loop in place with a valve to alow some 'hot' water to pass directly to the themostat without starving the matrix. Running the return down to the waterpump should help limit air becoming traped in the matrix during fill up, and if it all plays up then it should be easy to add something like that thermostat spacer down the track.
Thats the plan anyway

Quote:

Originally posted by Joel I'm in the process of adding a heater to mine. Im using a festiva heater core in a home made enclosure but the mob I'm buying my A/C bits off sell a variety of aftermarket heater cores with fans like this

I'm doing the same thing but using a commodore heater tap connected to the original heater cable as a bypass.

probbaly have it done just in time for winter finishing, and get the A/C going by the time it comes around again