Heater pipe layout on Amazon
 

My heater pipes need connecting in the engine bay of my B18 Amazon .
It is ages since the engine was sourced and ive just noticed there is a plug in the back of the head rather than the 90 degree pipe. Is this common ? All my other engines had the pipe and Im wondering how the head gets cool and also how the heater pipes and the one from the water pump under the manifold will work and connect up ? Any thoughts anyone ?

R122;

A simple plug in the back of Cyl Head is not common, and it is something I've ever seen before (on cars...don't know so much about marine B18s!)...it eliminates the Heater Core Loop entirely (so this suggests a brute-force solution to a leak in this loop in the donor vehicle, or origin from a boat maybe...if your Heater Loop is not known to leak, I'd go ahead and remove this plug, and reconnect normally).

...just wondering...what does the return from that loop at (8) into Water Pump look like?...that's a smooth tube fitting...one can't just wang a plug into that, and it would need to be closed off if Heater Core Loop was abandoned or be a leak in the Cooling Sys...

https://www.sw-em.com/cooling_system...low_detail.jpg

Source: https://www.sw-em.com/Cooling_System...cooling_system

Cheers

heater woes
 

Hello Ron
Thanks for your thoughts . The engine was cobbled together from several donors but the heater in the car was fine . I am resigned to the idea that i will have to take the head off remove the plug and retro fit a 90 degree section . Of course the engine is now in the car which makes getting to the plug (a sunken allen key design ) tricky .. might as well do it properly ,ive been 4 years on it so far !

cheers

Alan

R122;

"i will have to take the head off remove the plug and retro fit a 90 degree section"...I don't know about you, but I would expend a fair amount of effort and creativeness to access and remove that plug, without removing the Cyl Head!...if I understand a "sunken allen key design" right, wouldn't simply shortening the short side of an Allen wrench be enough...?...that departs the hole at right angles and would take very little room between engine and firewall, but would allow applying torque to remove...

And the state of Heater Loop return into the Water Pump still interests me...

Cheers

I think the normal angle brass fitting is BSP taper thread so once you get it started it should come out easily. As Ron said, a shortened Allen key should do the trick. Brookhouse do the brass elbow if you don't have one.