Heater Block Off Plate

[scannon]

I decided I needed something to block the flow of air through the heater core since the valve does not turn the hot water completely off. I can feel hot air blowing into the foot well through the heater vents.

 

I made this from a 1/4" thick sheet of black rubber. It is held in place with two picture hanger suction cups. A quarter turn on the metal part releases the rubber plate and it can be lifted out. I went with the suction cups as I didn't want to drill a hole in the heater housing. It took all of 20 minutes to design, engineer and install.

 

I'm thinking about removing the heater completely this winter. Should save a few pounds and clean up the engine compartment as well as under the scuttle.

[pksurveyor]

It looks a lot more professional than my card board insulation installation. My 2003 has the same type of heater as yours and it leaks very little hot air into the car. But the 2009 has the round blower heater and a lot more hot air comes thorough.

[bsimon]

I'm thinking about removing the heater completely this winter. Should save a few pounds and clean up the engine compartment as well as under the scuttle.

 

Yes Luke, come on over to the dark side...

 

I never could quite understand the logic of having a heater in a 200HP Seven. It's like installing a cab heater in a steam locomotive. :ack:

[southwind25]

be careful..

 

back when i was racing my 1275cc sprite...some people would blank of the heater inlet/outlets, and cook the head!!

when someone would blank them off they would develop a steam pocket and that part of the head wasnt getting properly cooled.

 

i would always run a line that fed back into the cooling system. that way i was getting good circulation through the inlet outlet ports and it aided cooling.

[solder_guy]

I would always run a line that fed back into the cooling system. that way i was getting good circulation through the inlet outlet ports and it aided cooling.

 

Hmmm ... interesting .. I may think of doing this .. at least it will prevent sludge from building up too..

[scannon]

It was my intention to run a bypass hose between the head and the water pump when I do remove the heater.

 

On my engine it is probably not needed as the heater feeds from just upstream of the thermostat and dumps into the water pump inlet.

 

However, the cooling system pressure tank is T'd into the heater hose that connects to the water pump so the bypass will remain just to connect the pressure tank to the system.

[bsimon]

i would always run a line that fed back into the cooling system. that way i was getting good circulation through the inlet outlet ports and it aided cooling.

 

It depends on the design of the coolant passages in the head. Some engines do use the heater circuit to effect flow in certain areas. Most modern designs have eliminated this method of cooling for reliability reasons. Some newer designs bypass the rad internally when the 'stat is closed as well.

 

A good rule of thumb; If the original heater circuit uses a 3 way bypass valve, chances are the engine needs that circulation to cool something that might be vital. If the heater valve is a simple throttle, the engine probably has properly designed internal passages that preclude the need for external circulation.

As always, check with a reputable builder that is experienced with the particular prime mover in question.

[MHKflyer52]

You can always just remove the heater and connect the hoses to each other so circulation continues as if through the heater box as it wasstill in place.

Just a thought and a simple solution that would let you reinstall the heater box fairly easy with out a lot of fuss.

[supersportsp]

Your solutions are all pretty high tech. I just used three pieces of duct tape over mine.

 

Question. Is there a way to block this down stream instead of at the inlet so it still gets airflow to the core, just not allowing any to go to the passenger compartment?

[scannon]

Your solutions are all pretty high tech. I just used three pieces of duct tape over mine.

 

Question. Is there a way to block this down stream instead of at the inlet so it still gets airflow to the core, just not allowing any to go to the passenger compartment?

 

What's high tech about a piece of rubber and two suction cups with picture hangers hooks attached to them?

 

There is one entrance and four exits to the heater system. If you block all four exits that heater box is going to get very warm and radiate heat into the cockpit.

 

You might be able to add a duct to the outside of the car but it would take up space and you never know what will happen when you try to direct air around various components of a car. You might end up with a reverse flow from what you expected.

[supersportsp]

What's high tech about a piece of rubber and two suction cups with picture hangers hooks attached to them?

 

Its all relative, but you solution actually required thought. I was going to use cardboard, but then I was like, why not just duct tape it?

 

So, what I am reading here is that there is some belief that the heater core needs the ventilation passing through it? If the bypass valve is working properly, wouldn't there be limited risk here?

[MHKflyer52]

So, what I am reading here is that there is some belief that the heater core needs the ventilation passing through it? If the bypass valve is working properly, wouldn't there be limited risk here?

 

No not so.

Most heater control valves that I have seen and used are usually a true valve without a bypass when closed and allow you to open the valve to a certain setting so it only lets a specific amount of coolant through. A good example is the heater valve on an MGB as it is cable controlled and is controlled by a knob on the dash which moves the arm on the valve to open it a certain distance which lets coolant flow into the inlet side of the heater box to provide heat to the passenger compartment or defroster vents when air flows through the heater box core (think small radiator).

Back to blocking the Heater to prevent heat from coming into the passenger compartment is done all the time providing that your heater control valve is not leaking internally and allowing hot coolant into the heater core area by just closing the valve that lets coolant from the engine into the heater box.

Blocking the air flow to the heater box will not stop the radiant heat from entering the passenger compartment if the heater valve is bypassing or leaking into the heater box when it is closed.

Replacing the heater valve is one solution another is to unhook the inlet host to the heater box and then connect it to the return hose thus bypassing the heater box and preventing heat from getting into the passenger compartment but not air flow for ventilation if needed.

At this point you can then cover the intake of the heater box with whatever you have handy or even remove the heater box completely and place a blank off plate over the area where the heater box was to prevent hot air from the engine compartment from entering the passenger compartment through the opening that the heater box was blocking.

If you remove the heater box you can actually block off the hose's on some engines but on some engines the water jackets and hose's also let the coolant flow to areas that might not have good flow when blocked off and not running through the heater core so that is why you would hook the inlet hose to the outlet hose instead of blocking these hoses off at the engine.

Also do you understand that most people remove the heater box from the car for a couple of reasons; 1. To reduce the amount of weight in the car for racing. 2. To eliminate it from the behind the dash area to make more room. 3. To eliminate heat transfer into the passenger compartment because they live in an area where heaters are not necessary like where I live in Southern California. 4. Because they sometimes develop leaks and are expensive to replace.

Hope this helps.