Heater valve question

[bigjones]

This is a hose from Lowes:

The DPO unfortunately removed the heater control valve so I was thinking of cuting that top hose from the heater box and inserting that 1/2" valve:

Thought I'd better check to make sure it is not a bad idea.
Cheers

 

[regularman]

I would think it would be fine. Anything to stop the flow of water though the heater. I am not up on how the spit engine works with the water and all. It all seems backwards under the hood.

 

[JPSmit]

FWIW I'm not aware that there ever was a heater control valve on the 1500's - though I'm contemplating the same thing. If you put the valve there and shut it off, it won't mess with flow elsewhere will it?

 

[SilentUnicorn]

1500's have heater valves. They also have a bypass to route coolant around the heater when the valve is closed. Pictures here https://www.britishcarforum.com/bcforum/u...tion#Post631803

i would not just arbitrarily block the heater core off without a bypass.- you could be asking for big trouble.

m

 

[JPSmit]

I would love someone else to weigh in here but I'm pretty sure that is a later addition. It looks like they have taken the hose off the junction that used to go to the water choke for the Zenith Stromberg - for sure my car had nothing that looked like that and I can't imagine the PO's taking it off since most everything else was there.

 

[tweety]

It's hard to tell, but it looks like that bypass is still there on your car.

My '79 had a valve when I got it. It sure seemed like it had been there since day one. The pars diagrams show one. It leaked pretty badly and was getting worse over time.

I replaced it with a valve very similar to what you're thinking.. It works great.

 

[RickB]

My 78 had the valve too.
I'd like to put in a bypass valve, on my list of things to do - that heater is cooking me. Not bad on cold mornings though.

 

[bigjones]

Thanks guys for saving me from myself.

On my car at least, two hard "T"s are already there and look factory to me.
One "T" at the end of the hard line coming out of the intake manifold and there is another "T" on the hard line that runs down at the back of the block.

All I need to do is install the valve in the LOWER hose that comes out the heater box. (correct?)

JP, I'm betting there are two holes your bodywork where the valve used to be:

Cheers!

PS Yes, you are quite right Tweety. Thanks.

 

[RichBall]

I will second that the 1500's came with the heater shut off valve as shown in the pictures. The usual path for the water to the heater comes off a tube directed off the back of the water pump and returnes via the intake manifold. If you have the water chock as I do, this is split off from here also. You can see the valve and some associated hoses for the diffrent options.

https://www.victoriabritish.com/icatalog/sm/full.aspx?Page=56

The stock heater shut off valve on my '76 was leaking a little and stuck solid. It is a brass twist valve with an O-ring used to seal it. I took mine apart, cleaned it up, replaced the O-ring, lubed it up and reassembled it. Works great and cost me less that a buck to do. It is easy to do since the whole valve is held together with a single set screw on the back side (hidden by the mounting bracket).

 

[SilentUnicorn]

Mine is a little different due to the twin su's. I have dealt with at least a half a dozen 1500's and they all had heater valves....

m

 

[Guest]

My 1500 had one but was changed out with a ball valve. It works great and I also had it looped when the heater was removed will no problems. My car never ran hot and it gets 100* down here sometimes (like now). IMO, block off, loop or valve at will.

 

[bigjones]

OK, it's a done deal and I'm very pleased!
Went on a test drive with valve closed and then open. No leaks and it's so nice to have relatively cool air coming into the cockpit.

Thanks for putting me right on the cooling configuration - it looked a big mess but now I understand it.

(Slight word of warning: the 1/2" ball valve from Lowes (American Valve, Made in China) was a real sloppy fit with 1/2" cooling hose. Not sure what is going on there - haven't a clue when it comes to plumbing. However, I tightened down real hard on the hose clamps and no leaks)

Cheers!

 

[JPSmit]

JP, I'm betting there are two holes your bodywork where the valve used to be:

OK I learned something today - I had no idea! Thanks for all of this. Could you guys post a pic or two of your setups - it sounds like a doable plan for me but, I still want the rad fluid to circulate while the heater core is off.

 

[bigjones]

I still want the rad fluid to circulate while the heater core is off.

It does! As others have explained to me, there are two loops. One of which is the heater loop. This can be isolated with the valve. If so, the water still circulates through the second loop.

I'll take a picture tomorrow - its now dark and raining - but all I done was cut the lower hose from the heater and insert that ball valve from Lowes.

Cheers!

 

[Guest]

I do think mine has a provision for that.

 

[JPSmit]

I do think mine has a provision for that.

can you post a pic too? thanks

 

[bigjones]

JP,

Here's a pic of the ball valve installed:

BTW, here's a pic of that hard pipe that disappears down the back of the block - see where it enter the water pump housing:

Cheers!

Well, kinda hard to see but its that lower pipe.

 

[JPSmit]

Cool! Yes, I know and have the pipe - so, presumably it doesn't matter which line it goes on?

 

[bthompson]

Here's a pretty clear shot of my hose routing, if it helps: