heater Mk1 cooling system heater connections

[AlanL 0]

Hi 

I stumped !!!!! ( or reached my level of understanding) 

I have a Mk1 Airflow ( import) with a 711m 16 crossflow  and I'm working though it. 

Effectively the heater is on all the time and no heater valve is installed. 

The attached picture should show what I have but clearly does not show what is missing@@@@ 

The return pipe from the heater deadheads into the inlet manifold ( for twin choke) but I'm lost as to  how that circulates and where the line should go to

I can put an inline heater valve in the supply line but don't think that all that needs done  

 

[SusanButcher 33]

Apologies if you know this already, but the normal Mk1 heater system doesn't have a water valve. The  hot water circulates constantly through the heater core, and the amount of heat reaching the car's interior is determined by the position of the two flaps in the heater box that control the air flow through the core. If your car originally had the "heavy duty"' heater system, then there is only one flap in the heater box, and there would have been a dashboard-controlled water valve that screwed into a hole on top of the engine block. So if you've got the normal constant-flow system, the flaps are faulty. I think the circulation of the heater water is in the opposite direction to the arrows, because the water flows down the radiator and into the pump.

Edited June 2, 2023 by SusanButcher

[AlanL 0]

Firstly thank you Susan for taking the time to  respond,  I do  appreciate it ! 

very helpful info for me! 

Flaps may have been open at time of testing !!!!!

Its a South African car and as such may be akin to the Australian cars anyway ( including the BW axle )

The previous owner said there was no heater fitted when he imported it,  the heater unit in the boot  as a spare part, so  he installed it ( correctly ? was my issue)

I was very suspicious, which as you can see in the picture ( 4" in front of the righthand yellow arrow)  there is a joint in the line from the water pump where possibly an inline shut off valve could have been. 

The heater unit has only one lever  ( OFF/ INTERIOR /SCREEN)  plus the two  flap controls +fan,  so suspect  this unit is the "light weight"   Scots don't need them anyway @@@

  

 My only query now is the circulation route as can't see an outlet on the inlet manifold and never seen a water jacket in a head before  ****

I did take the inlet manifold  hose off today and a constant trickle of coolant ( hot) came from the manifold and no other hoses appear to  be attach,  had to  top up the radiator  for the losses

bloody  weird but will pull the motor in the winter to  tidy it up so  will have that manifold naked to  get a good look from the underside clearly

I'll leave as is and move on to the other stuff I have to fix 

thanks again Susan ( very  helpful) 

[AlanL 0]

correction

just seen the same inlet manifold on Ebay   flange side water jacket clear as day 

I'm a numty 

 

[SusanButcher 33]

No trouble Alan. Good luck sorting out the heating. I should also mention the non-heated "fresh air" system. This has the same basic box as the one-flap heavy duty system, but no heater core or fan. Most Australian Cortinas had this setup because it rarely gets below zero here, and if it's really hot you just reverse the front quarter-lights for a blast of air in your face. No good in a traffic jam though! Same deal in South Africa I expect.

[AlanL 0]

Ha Ha 

You are educating the Northern Hemisphere Susan

I'll give you a shout on my next inquire

thanks again for your contribution to this forum