Remove Heater box wrapped over exhaust?

[Barking Squirrel]

Hey Samba Folks.
Looking for advice on what to do with the heater/exhaust on the 1980 air cooled Matilda.
I have removed the auxiliary heater and supply parts from the engine. CO2 leaks, fire, stuck flaps, etc made it a necessary choice to remove as it was 43 years old and suspect.
Curious what to do with the remaining heater exchangers around the exhaust. Leave them? Remove the outside sleeve and let the exhaust breath?
What would you do?
Thanks Paul

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1980 Vanagon L 235k, Dual Carbs, "Mattie". Air Cooled.

[zerotofifty]

The heater shroud on the pipes are needed to keep the heads cool on VWs. If you remove them, you should add shielding. But why remove them, if you fear exhaust gases in the cab, dont use them, but leave them in place. If you have an exhaust leak, well you should fix it by replacing with better units.
Did you gasoline heater actually catch fire, actually pump CO (CO2?) into the cabin, or was it you suspect it might?
Anyway ripping of the shrouding is not good for the engine. the shrouding blocks radiant heat from cooking the heads, and air flow thru them also blocks heat. the air flows thru them even when heater is off.
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Sorry About That Chief.

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[djkeev]

IIRC .... newer air cooled heater boxes ALWAYS have air flowing through them.
The air either flows into the passenger cabin to heat it or it is dumped on the road.

The cooling jacket (heater box) MUST be operational for proper engine cooling.
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Ghia
http://www.thesamba.com/vw/forum/viewtopic.php?t=392473

Vanagon
http://www.thesamba.com/vw/forum/viewtopic.php?p=6315537#6315537

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https://www.thesamba.com/vw/forum/viewtopic.php?t=482968&highlight=74+super+vert

[Barking Squirrel]

Thanks for the wisdom. I will be leaving the jackets on.
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1980 Vanagon L 235k, Dual Carbs, "Mattie". Air Cooled.

[Xevin]

Was the heater a Ba6 under the car style or Ba4 torpedo style in the engine bay you removed?
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Keep on Busin'

[zerotofifty]

That thing in your last photo, with the domed metal cover is the heater valve. The heater control cable is hooked to it. When heat is on that valve directs the flowing air into the cabin, when heat is off, the flowing air is directed out from under the dome, bleeding out under the car, hence there should ALWAYS be air flowing thru the heater exchanger boxes when engine is running, this assumes they are hooked up correctly to the fan house. In addition to the fan house supplied air (fan powered by crank shaft) there is the auxiliary electric booster fan in the engine bay. This fan need not be on for air flow when heater is in off position. HOWEVER, the electric fan should have one way check valves on its ports (flaps) that only open when electric fan is running, and seal when electric fan is off. This in combination with sealed plastic or paper hoses from electric fan to the heater exchanger boxes are NEEDED to...1 Keep the air flowing thru the heater boxes, and 2... Keep the hot air from going into the engine bay, which will in effect preheat the engine cooling air (bad!!!) So make sure all your heater hoses and those electric fan check valves are in place and sealed correctly. As this does affect your engine temperature and the longevity of the heater boxes. This is IMPORTANT!!!
_________________
Sorry About That Chief.

Give Peace a Chance.

Words to live by.

[AZ Landshaper]

no hoses so their inoperable. Gonna have some cold nova scotia air blowing through your heater ducts unless you capped off the ports for the heater hose. Im curious to see what the hell else you might be cancelling. Those motors are highly dependent on the ducting of cool air around the heads and deflecting hot air is part of that equation. you can go from a hot dog to a boat anchor in 100 miles of hilly terrain. Faster than one can say "dropped valve seat".
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85 Weekender w/ EJ22
Previously
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and a 67 bug.

[zerotofifty]

[Barking Squirrel]

Thanks for all the thoughts.
There was an axillary heater under the van that was rusted out and disconnected by PO and myself. Most of the flaps, cables from the exhaust heat exchangers were rusted with holes and are removed. All ports that could allow cold air into the van have been sealed.

We have installed a Webasto Heater that provides hot air into the living space and to the dash blower should we need heat while driving and clearing the windshield. All engine tin and cooling flaps are in place and working.

My concern was around whether to keep air flowing through the heater boxes and not going into the engine bay since I am missing the "Heater Flap or Heater Control Valve (as Zerotofifty mentioned)" on the drivers side.
As AZ said. "hot dog to a boat anchor"

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1980 Vanagon L 235k, Dual Carbs, "Mattie". Air Cooled.

[MarkWard]

I am going to offer an alternate point of view. In this picture you can see the fresh air duct from the blower on the alternator to both heat exchangers. Not my photo.

The question I read is "is it ok to remove the "cans" aound the heat exchangers? I would say yes it is. There is no reason the engine would run hotter. If the above duct work is missing, I would cap the tin work so no exhaust heat can work it's way up from the exhaust.

In theory, the alternator blower would move cool air across the heat exchangers cooling them, but without the blower, they are running hot anyway. If you removed the cans around the heat exchangers I believe you will find cast fins that could remove heat when exposed to moving air.

I don't think its going to make the engine run hotter. An example would be removing the heat exchangers and running header tubes. This was common on earlier air cooled VW's

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[AndyBees]

[Barking Squirrel]

Thanks Andy and Mark. Very very helpful.
Mark, I have the same set up as your photo. All the piping is in place to allow the alternator fan to push cool air through the horizontal tube to the heat exchangers.
A few thoughts:

I suppose if the Heater Flaps are missing on the drivers side, the front end of the heat exchanger is open and therefore could allow air to be pushed (at highway speeds) in the opposite direction through heat exchanges and against the flow of the fan. That is a bad scenario. Hence your suggestion of "capping the tin".

Also I suppose replacing the heater flap or capping it wouldn't allow any air to flow across the heater exchangers, and therefore the exhaust would be like another time when the original heater was installed but not on: the flaps would be closed.

However, Andy, in your post, I am unclear if the flaps are closed, like when the original heating system was turned off at the dash, how any air could pass through the exchangers?

Just thinking....

I do like the idea of removing the tin around the heat exchangers so it behaves like the older style header tubes of previous years air cooled engines. So long as my engine seal, tin and flaps are good and groovy.
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1980 Vanagon L 235k, Dual Carbs, "Mattie". Air Cooled.

[MarkWard]

Got your pm. If you have the alternator blower and ducting, I’d leave that as is. Having the far ends of the exchanger open or minus the flaps is not the end of the world. I’d be inclined to resurrect the heat exchanger system. That’s just me.

To add some history. Prior buses and bugs used the engine cooling fan to push heat across the heat exchangers. When ambient temp required heat in the van, it was ok to borrow some of the engine cooling air for heat. In higher ambient temp, you’d close the heater flaps and all cooling air was forced over the engine cooling fans. If the heater system had air leaks, you’d lose some engine cooling. The 72 on buses with the type 4 engine had an electric helper blower and the aluminum shroud had two tiny hidden flapper valves. Buses and bugs with the type 1 upright engine had cooling hoses coming off the shroud to the heat exchangers. It was not uncommon in warm climates to remove the hoses and cap the outlets on the shrouds.

The Vanagon heat was a redesign. When functional it does an ok job. My description above is an over simplification, but more of an overview. If you’re going to strip the cans off, there would be no advantage to maintaining the alternator blower and plastic ducts if you have them. I see wanted adds for members looking to buy good used ones. Makes changing the alternator and belt easier.

[AndyBees]

[zerotofifty]

[Barking Squirrel]

This is perfect. Didn't realize the Heater Valves dumped heat under the van when the interior controls are set to off. Explains how there can be flow through the heat exchangers at all times. Makes sense to me now.
I will replace the drivers heat exchanger with one that allows this to happen.
Thanks,
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1980 Vanagon L 235k, Dual Carbs, "Mattie". Air Cooled.

[AndyBees]

[MarkWard]

[AndyBees]

[pathao]

That last photo brought me back to memories' lane (that is one of mine) and made me realize that I'm late to the show.

To keep it simple