Coolant flow in 1HZ and Glind heat exchanger

I don't know the construction of the heat exchanger but it sounds like your si set up co-current and your mates is counter current. ie yours has the flow of cold water running in the same direction thru the heat exchanger as the hot water, and your mates is reverse. if so, this will account for a difference in performance.

The coolant flow and the shower water flow MUST run in opposite directions and that is the way heat exchangers work in any application. To check if your coolant is running the right way, remove the coolant hose from the exchanger, the one right next to the shower outlet fitting. The coolant must be running from the hose into the exchanger to have correct direction of coolant flow.
Also with most 1HZ's, to get a constant flow of hot water, you should screw up the engine rpm to about 1200 rpm to get sufficient coolant flow to heat water, especially cold water. All diesels require more coolant flow than petrols and nearly all diesels benefit from the lift in engine rpm. Heat exchangers require a minimum of 6 l/min of coolanr flow in order to heat water sufficiently, some diesels at idle only pump through about 4 to 5 l/min, not enough, hence the increase in rpm to increase coolant flow and resultant heat.
The Troopie has a heater control valve and the 100 doesn't, but the coolant pipe on the back of the block on the passenger side of both is the feed line.
Another big area where heat is lost is when you may have an aftermarket turbo and water is tee'd off to the turbo. Some people put the heat exchangers in the line between the 2 tee's. What happens here is that the coolant flow after 1 tee is only about half as part of the coolant is diverted to the turbo and the other part runs along the main hose. This does nothing for either the shower or the turbo.
To do it properly, the heat exchanger must be plumbed into the coolant feed hose first and before it is tee'd off. This ensures the heat exchanger gets the full flow of coolant and the turbo gets its recommended amount of coolant. Otherwise both pieces of equipment will be compromised and not work to their fullest.
I hope this helps
Tim

Further to the above, if a heat exchanger is plumbed with the coolant and the shower water running in the same direction, you will get a blast of hot water for about 5 seconds and then it will run cold and even if you rev the guts out of the motor, you will only get very luke warm water. If yours is doing this, then it is plumbed in back to front and will never work. The efficiency of a heat exchanger is dropped by over half.
Simply flip the coolant hoses to opposite ends and hey presto it will wprk as it is meant to.

Tim,

Thanks for that; very informative. I suspect that mine is plumbed wrong, as the cooland inlet on the H/E (with the arrow for directional flow) is connected to the pipe on the drivers side of the block. If this is correct, then I would actually have the pumped water flowing in the same direction as the coolant (heatant?).

It works OK if you restrict the flow and up the idle, and it works pretty well when I recirculate the water into a container for wating up water etc.

I'm not even sure if I need the valve on the inlet side of the H/E either, as it never really gets hot enought to have to restrict the coolant flow, but, then again, if it's all plumbed wrong, it wouldn't make much difference anyway,

thanks for you reply,

Andrew

Hi Andrew,
It sounds like yours is plumbed up the wrong way. With a 1HZ, you should be able to get a constant flow of hot water at full flow simply by increasing engine rpm to 1200 and if you reduce the flow at the shower rose, it will get very hot.
As the 100 series does not have a heater control valve, you can still use the hose on the drivers side but it must run out of the firewall, into the exchanger and run from the exchanger into the hose on the drivers side. To fix yours, simply swap the coolant hoses to the opposite ends.
You won't need a flow valve either as these are only used to slow coolant flow down if the shower is too hot at idle.
Tim

Andrew

I have 1HZ Trooper with a shower in it and the sucker will 'boil you alive' if you are not carefull.

So I would suggest you definitely have something A' about in your set up.