9 replies to this topic

[mbolt998]

Like most Minis mine has a Bowden cable, on the other side from the choke, which you can pull to shut off a valve, which stops hot water going to the heater. I have never turned it off, thinking that it was better not to interfere. I also assumed that the engine would cool more if the water was going round the heater matrix as well as the radiator. But it now occurs to me that since the heater is connected in parallel to the radiator, and there is nothing to bypass it, this might not be true. If you have the heater on, some of the water comes out of the engine, goes around the heater, and then goes back into the engine. It will lose less heat that way than if it had gone through the proper radiator. Since there is also only one water pump, with the heater off, it will pump water better through the radiator. So maybe it's better to actually turn the heater off in summer, crazy though it sounds? (Assuming it's hot-- it's so cold this summer in UK I actually want the heater on!)

[timmy850]

The heater circuit normally bypasses the radiator. However the heater core behaves similar to a radiator, but works best to cool when it's got air passing over it

 

The other factor to consider is that if the heater takeoff point is on the top end of the head on the drivers side it'll help keep an even temperature across the head and avoid that end of the head getting hot spots. 

[nicklouse]

What year is the car?

 

the cooling circuits are not all the same.

 

stopping the flow through the heater does different things depending on the set up.

[mbolt998]

What year is the car?

 

the cooling circuits are not all the same.

 

stopping the flow through the heater does different things depending on the set up.

1979 1000.

[Ethel]

They are all basically the same in this respect. The pump can draw water from either of 2 parallel circuits.

 

I think you could look at it as a whole & see how much heat exits the system where. The heater won't affect the radiator unless it reduces the flow through the latter enough to make the outlet temperature drop more.

 

There's way more heat in the water than can be transferred in to the air. It's got 4 times the heat capacity & about a 1000 times the density.

[slidehammer]

I never turn mine off on the valve, only by the use of the flap on the heater its self. I have used the heater with the fan on (on hot days in traffic) to help take a bit of heat off the engine and you can see the gauge gradually move down once it is left running. The other reason I don't move the valve is they can start to leak once disturbed, unless they are moved regularly. 

[coopertaz]

it does seem true theory wise but know for a fact that using the heater to cool engine, especially waiting to get into shows does work. also leaving heater tap on may prevent build up of crud in the heater matrix

[Spider]

Yes, it does help with cooling. Here's some advice from Special Tuning in which they mention the heater;-

 

 

[nicklouse]

Had to google 2A803.

[mbolt998]

Yes, it does help with cooling. Here's some advice from Special Tuning in which they mention the heater;-

 

 

 Brilliant info thanks!