Heater Delete

[robsad]

I would like to delete the plumbing and function of my heater. There is the elbow on the cylinder head below the timing cover that goes to the heater and the other small outlet coming off the water pump. Not sure which is the supply and which is the return but can I just connect these two outlets with a piece of hose ? Seems like this should work. Has anyone else done this ?

Bob

 

[carl]

Yes, short section of hose between the two spigots will work just fine.

 

[Dr.Jeff]

For a completely clean conversion you could remove the fittings completely. The one on the head is threaded so it could be replaced with a flush fitting plug. The hose barb on the coolant pipe (between the water pump and T-stat housing) would also need to be plugged or eliminated. There is another pipe with no hose barb (early 1300 engines I believe?) that can replace your existing one. Or your pipe can be modified. Or make a new one from stainless.
All of this is extra work but then no bypass hose is needed and it will clean up things quite a bit.

 

[rachaeljf]

Cap the pipes off. Connecting them with a short length of hose will short circuit the coolant pump and guarantee overheating!

 

[Dr.Jeff]

Great point. The hose will effectively be re-routing hot water back to the water pump (then recirculated through the engine) without going through the radiator.

 

[X1/9Cruiser]

Just FYI, some states (Virginia for one) won't pass your car in a state inspection without a
working defroster (i.e. a defroster that blows warm air). Don't know if it applies to you or
not.

 

[robsad]

Great point. The hose will effectively be re-routing hot water back to the water pump (then recirculated through the engine) without going through the radiator.

I'm confused. The heater circuit is essentially a closed loop. The coolant that leaves and goes to the heater core returns via this loop and never gets to the radiator. So what difference would it make what length the loop is ? If you put in a short piece of hose or the existing heater hoses it's still a loop. This short hose would not disturb the main flow from the thermostat housing outlets to the radiator. Maybe I'm not understanding the flow path of coolant. Help !

Bob

 

[robsad]

Just FYI, some states (Virginia for one) won't pass your car in a state inspection without a
working defroster (i.e. a defroster that blows warm air). Don't know if it applies to you or
not.

My car has a permanent antique plate and registration. PA does not require inspection for antiques.

 

[Dr.Jeff]

The difference here (with a bypass) is the loop is wide open at all times. In the case of a heater it is usually a closed loop, and only open when the heater is on. That's also when its cold out so there is less need for the water to get cooled. Also the heater core acts as a radiator when it is open.

So the water path for the system as a whole is: cool water from the radiator goes to the water pump, through the engine where the water gets hot, out to the radiator again. The heater hose connections are at each end of the engine path: the hot water (after going through the engine) comes out of the head (the barb by the alternator) to the heater core, back to the engine just before the water pump (the barb on the coolant pipe, which is normally the cooled water). When the heater is removed and the bypass loop added, the hot water from the head goes directly back to the water pump inlet (at the pipe). Therefore hot water is recirculated through the engine without going through the radiator first.

That's why Rachael's suggestion of plugging the fittings is better than adding a hose loop. This way no water passes from the hot head back to the water pump.

 

[lookforjoe]

Plus having a piece of heater hose routed over the exhaust manifold where it can get nice and crispy is just a bad move. Removing the I/O of the circuit makes the most sense.

 

[kmead]

I'm confused. The heater circuit is essentially a closed loop. The coolant that leaves and goes to the heater core returns via this loop and never gets to the radiator. So what difference would it make what length the loop is ? If you put in a short piece of hose or the existing heater hoses it's still a loop. This short hose would not disturb the main flow from the thermostat housing outlets to the radiator. Maybe I'm not understanding the flow path of coolant. Help !

Bob

Simply put, the heater is in fact a radiator.

If your car starts to heat up you can dump a notable amount of heat to draw the temp down.

So, effectively running coolant from the head through the heater will cool it and return cool coolant to the base of the pump.

Going direct from one to the other will bring hot coolant directly back into the pump and will cause overheating.

 

[carl]

Or you can shove a bolt shank into the bypass hose and it will effectively block the circuit. Kind of depends on how much work you want to put into this. When I deleted the heater on my Bertone I put a threaded plug into the opening in the head and installed an early pipe without any heater hose barb on it. A short length of hose is the easiest and I guess my idea of a plug in the center of the hose will calm those who indicate the short circuit is not a good idea for ultimate cooling. As for the hose getting crispy from engine heat, it just mimics the stock hoses.

 

[Isotope9]

Perfectly timed post...I just discovered my heater core is leaking (coolant coming from in the heater box, heater valve and connections are dry) and I'm not interesting in removing the dash to replace it as there are precious few days of driving left in my neck of the woods.

I'm going to remove the hoses, cap them off so nothing makes a nest in them, and put temporary hose/caps on the inlet/outlet so I can drive the car. I'll deal with the heater core over the winter, if at all.

EDIT: quick glance at the shop manual shows it's possible to remove the heater core without removing the dash...but yeesh, what a job!