Heater Control Valve Idea

[carfreak6970]

Hello,

Would there be any interest in a rebuild-able heater control valve?

I have a 70 Polara that I would like to take on a road trip to the beach one day and my old man was always hesitant on taking that car to far from home due to the heater control valve and its proneness to cracking. He was concerned that you could carry a spare but that one may not even be good.

I have access to 3D modeling software and a machine shop. My background is in mechanical engineering, specifically designing valves. I was thinking of seeing if I can get one design and tested to hopefully use easily sourced seals.

Thoughts?

 

[david hill]

If you can replicate the OE control valve performance there are too many applications it would cover. An excellent choice as many of us could use them. With your engineering skill I'm all for it.

 

[Chrome58]

AFAIK, universal ones are already on the market.

 

[Big_John]

If you do build one, the two suggestions I would have would be to make it look like the original plastic version and shut off both inlet and outlet rather than just the inlet. I understand that might not be possible, just adding food for thought.

 

[Carmine]

All-metal replacement has been the only thing on shelves for decades.

 

[live4theking]

Hello,

Would there be any interest in a rebuild-able heater control valve?

I have a 70 Polara that I would like to take on a road trip to the beach one day and my old man was always hesitant on taking that car to far from home due to the heater control valve and its proneness to cracking. He was concerned that you could carry a spare but that one may not even be good.

I have access to 3D modeling software and a machine shop. My background is in mechanical engineering, specifically designing valves. I was thinking of seeing if I can get one design and tested to hopefully use easily sourced seals.

Thoughts?

If you choose to pursue this and you need help with seals you should contact AJ at Sealing Specialist and Services in Glenshaw. He's a great guy and like to do unique things.

 

[CBODY67]

After I replaced trouble-prone OEM valve with the aftermarket one, I noticed that the vacuum bleed in the dash control (factory a/c), for the temp adjustment, would vibrate at certain throttle positions. I could vary the sound with just a change of vacuum levels. Apparently the smaller vac diaphragm on the aftermarket unit didn't dampen the vacuum pulses from the intake manifold vac feed as well as the OEM unit did. Worked well, past that.

That was in the later '70s.

As for a single-hose vacuum controlled valve, GM has several applications of those.

Check the applicability of an exact repro unit and related copyright/patent issues, too. Making it with a license from Chrysler/FCA, but with improved materials, might be a better option.

CBODY67

 

[ceebuddy]

Not wanting to crash this thread, but two observations:

- After replacing the original unit with the Everco H1949 all-metal unit depicted above I noticed I couldn't keep a steady temperature from the heater in my 1971 Sport Fury. I was always readjusting the lever trying to keep a constant temperature.

- Note that the Mopar valve (and also the Everco H1949) has different diameter inlet/outlet hose nipples on the actual valve, probably making it difficult to replace these with GM or other aftermarket units.

 

[ceebuddy]

If you do build one, the two suggestions I would have would be to make it look like the original plastic version and shut off both inlet and outlet rather than just the inlet. I understand that might not be possible, just adding food for thought.

I think the original valve is cleverly designed in that it allows a blending of the incoming hot water with the colder water flowing back to the engine, making for a more constant temperature at the heater. This might explain my observation using the Everco unit as described in my previous post. I remember opening an old (cracked) Mopar valve and trying to figure out how the water flows, but I forgot to take a picture. Does anyone have an old/leaking unit to open up and look into?

 

[Big_John]

I think the original valve is cleverly designed in that it allows a blending of the incoming hot water with the colder water flowing back to the engine, making for a more constant temperature at the heater. This might explain my observation using the Everco unit as described in my previous post. I remember opening an old (cracked) Mopar valve and trying to figure out how the water flows, but I forgot to take a picture. Does anyone have an old/leaking unit to open up and look into?

I don't know. After reading the FSM on my '70, I think it just restricts flow to the heater inlet. The aftermarket piece does this and, interestingly enough, the auto-temp heater valve just works on the inlet side with a straight through connection to the outlet.

Of course, I've never had one of those valves apart so that's just really speculation on my part. I do have to wonder if the water flowing back to the block would be that much cooler that adding a mixing valve to the system would be worth the cost.

Interesting stuff!

Myself, I just want the water in the heater core not to be hot when the A/C is on.

I thought about using this valve, but after what I could find, the valve shown works backwards from the original valve with vacuum applied stopping flow rather than vacuum applied creating flow. Optional Heater Control Valve for Better AC cooling.

I went with a small manual valve in the line for summer operation after the vacuum valve to be sure the flow is completely stopped. The A/C in my 'vert is only used when it's too hot for the top to be down and maximum cold is desired.

 

[commando1]

Myself, I just want the water in the heater core not to be hot when the A/C is on.

 

[Big_John]

View attachment 259597

I had a big old nasty ball valve from an air line until I found a decent replacement at the price I wanted to pay. I remember lifting the hood at Carlisle for someone and getting a "WTF?" look.

I have one of these in the line now... and I seem to remember first seeing one in some Florida guy's two tone Formal.

 

[Nadir Point]

 

[ayilar]

Looks like there are two threads, simultaneously, on the same topic. Here is the other thread, where @saforwardlook and others, including @Big_John, share their experiences with the valves. Reliability is discussed -- using a large sample in Steve's case, which is extremely useful to know.

@71Polara383 found out last week that the valve in my '71 Monaco (the one I bought a couple of weeks ago, which is now at his shop for a health check) was leaking.

I hesitated between NOS ("teapot" red/black/silver look, made partly of bakelite) and all-metal ("mushroom" look, made by Everco). In the end, I hedged / prevaricated:

--> I bought both a NOS replacement (in case I restore the Monaco to new condition) because Steve found me one at half the price that most other places seem to ask;
--> I also bought an all-metal one, which Wyatt has installed.

I'll report about the temp performance of the Everco H1949 in the other thread.

 

[carfreak6970]

Ayilar, thank you for that. I guess that metal one is the best option for longevity. I have heard some rumors that the metal ones dont provide a smooth transition for temperature changes. Did you find that to be the case with your metal one? Having a valve that leaks sucks, but having a valve that doesnt allow you to dial in the temperature of the HVAC system isnt good either.

 

[ayilar]

Ayilar, thank you for that. I guess that metal one is the best option for longevity. I have heard some rumors that the metal ones dont provide a smooth transition for temperature changes. Did you find that to be the case with your metal one? Having a valve that leaks sucks, but having a valve that doesnt allow you to dial in the temperature of the HVAC system isnt good either.

I’ve seen the same comments on temp control but decided to go with @saforwardlook ’s advice prioritizing longevity. He did not mention issues with the “quality” of the heat inside the cabin, so if there is any such issue I’d guess they were minor. Steve, it would be great if you could confirm your experience across many cars in this respect?

I’ll report my own experience once salt is gone from the roads and I can start driving the car next month. Right now, Medina is getting a full service (oil, air and oil filters, various gaskets, voltage regulator, etc. ) courtesy of @71Polara383.

 

[saforwardlook]

I’ve seen the same comments on temp control but decided to go with @saforwardlook ’s advice prioritizing longevity. He did not mention issues with the “quality” of the heat inside the cabin, so if there is any such issue I’d guess they were minor. Steve, it would be great if you could confirm your experience across many cars in this respect?

I’ll report my own experience once salt is gone from the roads and I can start driving the car next month. Right now, Medina is getting a full service (oil, air and oil filters, various gaskets, voltage regulator, etc. ) courtesy of @71Polara383.

I would agree that the temperature modulation on the metal valve is not nearly as good as the factory unit, but one can always blend in additional air through the manual vents in the car if necessary or drop one of the windows a bit or reduce the fan speed or a combination of choices to achieve what you want. For dehumidification, use the a/c in conjunction with the heater as needed too. I have rarely needed to do any of that though, but then I live in a warmer climate than most as well. I just don't think the factory unit is worth putting up with the cracking and leaks that come along within two years on average if you drive the car much. Those units are increasingly hard to find and costly as well. The choice is yours.

 

[ayilar]

Ayilar, thank you for that. I guess that metal one is the best option for longevity. I have heard some rumors that the metal ones dont provide a smooth transition for temperature changes. Did you find that to be the case with your metal one?

No issues to report. I have not driven the car much in colder weather, but when I did, the heater performed flawlessly and I got the temperature I wanted.

 

[carfreak6970]

okay good to know! thank you! Ill have to pick one or two up. One for the shelf and one for the trunk in case of emergency. The Polara is slated for a beach road trip sometime soon

 

[ayilar]

I've never seen pictures of your Dad's vert. Would he/you be willing to share some?

PS: are you off to the NJ shore (paging @polara71) or the Delmarva area? If the latter, and the dates work, I'd be happy to meet you somewhere along the way with my own '70 ragtop. As you may know, it's also a Penna car (the first and the second owner were neighbors in Pottstown, PA; I am there third owner).