TR7 & TR8 Mailing List

TR8 heater valve

0 Members and 1 Guest are viewing this topic.

Benjamin Zwissler

TR8 heater valve
« on: May 12, 2018, 08:11:20 PM »
I've been doing it every summer for over 10 years with no issue.



Ben



On Sat, May 12, 2018, 7:50 PM Mark Elbers <elbersm@telus.net> wrote:



> For a TR8 with a default option heater (no Air conditioning)  the engine

> coolant is always circulating through the heater matrix from the back of

> the

> intake manifold through to the water pump.  Even though the airflow can be

> cut

> off, the constant coolant flow still introduces some heat into the cabin on

> hot sunny days.

>

> Ib d like to fit a coolant shut off valve to the heater, but Ib m wondering

> if the coolant flow through the heater is necessary for normal engine

> operation.

>

> Is there any danger to the engine if this flow is blocked?

>

>

> Sent from Mail for Windows 10

> --

> .

> Archives provided courtesy  http://www.triumphwedgeowners.org

>

--

.

Archives provided courtesy  http://www.triumphwedgeowners.org



"John M. Sanders"

Re: TR8 heater valve
« Reply #1 on: May 12, 2018, 08:35:43 PM »
I too installed an inline cut off on my TR8 DHC non a/c car. No problems in

the past 5 years with it.

Cheers

John Sanders



Sent from my iPhone



>

Michael Madden

Re: TR8 heater valve
« Reply #2 on: May 12, 2018, 08:45:41 PM »
I would be interested in seeing what you guys did as for connections and

plumbing on this issue. I too was curious ....

Mark Elbers

Re: TR8 heater valve
« Reply #3 on: May 13, 2018, 10:50:41 AM »
Michael,  I have done it yet,  but Ibm hoping to rebuild a spare heater core

this year, hence the interest in incorporating this mod.



Ideally I would like to have a valve that operates in an bHb diverter

configuration,  when activated it loops the coolant from manifold directly to

water pump and when not active,  loops in the heater matrix.  But most seem to

be a simple on off switch.  Ibd also like to use an electrical valve,

thinking that adding a micro switch to the heater controls is easier than a

Bowden cable.



My thought was something like this VW/Audi part:

https://www.ebay.com/itm/Coolant-Solenoid-Valve-Heater-Control-Fit-Audi-A4-A6

-C7-A8-Q5-VW-Golf-1-8T-2-0T-/272707807708



VW also used this manual valve in all sorts of models for 20 years:

http://volkswagenownersclub.com/vw/showthread.php/27473-Internals-of-a-Heater

-Valve.



Ibd also suggest something like the MGB valve fitted to the back of the

manifold with an old choke cable for control,  but the MGB crowd have done a

affair bit of work on this because their engine mounted valve is notoriously

fickle. Here are some ideas.

https://www.mgexp.com/article/heater-valve.html

https://www.mgexp.com/phorum/read.php?1,2008230





BTW ,  all these ideas apply equally well to the TR7 heater configuration.



Mark











Sent from Mail for Windows 10



From: Michael Madden

Sent: Saturday, May 12, 2018 5:45 PM

To: John M. Sanders

Cc: Benjamin Zwissler; Mark Elbers; tr8@mercury.lcs.mit.edu List

Subject: Re:  TR8 heater valve



I would be interested in seeing what you guys did as for connections and

plumbing on this issue. I too was curious ....

Bill Derksen

Re: TR8 heater valve
« Reply #4 on: May 13, 2018, 04:40:04 PM »
I tried the electrical solenoid valve. I mounted a micro switch to the

side of the heater box such that as soon as the HEAT control was moved

off the cold stop, the valve would open. Worked great - except that the

only valve I could find at the time that would physically fit had a very

small water passage, and wouldn't flow enough water to the heater core

to actually supply any heat to the cabin. So I wound up replacing the

solenoid with a small ball valve (such as used to shut off the water to

a toilet). I can JUST reach it from the driver's seat.



It looks like Mark found some better alternatives to what I had, so if I

ever have to have the dash out again, I may revisit the automatic valve.



To answer an earlier concern: the hot water to the heater comes from

just below the thermostat and returns to the inlet side of the water

pump. So shutting off this flow should have no negative effect.



(I attached a couple of photos my heater modifications - which will get

stripped out for the rest of the list. If anyone else wants to see them,

send me a note.)



Cheers

Bill

Mark Elbers

Re: TR8 heater valve
« Reply #5 on: May 13, 2018, 07:59:43 PM »
Thank you Odd,  it looks like you may have a winner.



Ibll take a look at availability on this side of the pond.



Cheers



Mark



Sent from Mail for Windows 10

"Karl Knowles"

Re: TR8 heater valve
« Reply #6 on: May 14, 2018, 09:24:37 AM »
Odd,



Is the Audi solenoid valve a variable flow, or on/off?  Variable flow would

require adding a resistive path (pot or linear taper) for heat volume

control to match what the OEM valve provides.  On/off only could heat the

cabin up excessively - in my neck of the woods.



Karl

Tallahassee, FL

Odd Hedberg

Re: TR8 heater valve
« Reply #7 on: May 14, 2018, 10:45:13 AM »
I don't know - I just thought it looked the part Mark was looking for

both flow vice and fastening vice...

/Odd





Den 2018-05-14 kl. 15:23, skrev Karl Knowles:

DAVID MASSEY

Re: TR8 heater valve
« Reply #8 on: May 14, 2018, 01:13:23 PM »
Variable flow is not necessary on the non-AC heaters since it has a bypass damper.  The damper varies how much of the air goes through the heater and how much goes around it and the variable mix will vary the discharge temperature.  The valve is only needed when no heat is needed.  But if variable heat is really desired you can fit a heater control valve from the AC version.



 



 



Dave Massey