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Does anyone know what size the heater hoses that go from the back of the cylinder head to the heater box are? Need to order some stuff to go with a T7 design heater box but can't get at the back of the head on the slug at the mo because it has stuff piled on the bonnet!

ill measure them tomorrow but I'm pretty sure they are 25mm

Sorry Jim - I thought you'd been told on other thread.

The one I have here is 25mm.

Presumably that's external diameter. Need to know internal if you have the bit of hose handy.

The end of the hose that connects to the heater box from the heater water valve is 17mm inside diameter but the pipe from the heater water valve to the back of the head is 24mm inside diameter on the end at back of the head and 17mm at the valve end..I think the other hose to the heater is 17mm inside diameter both ends....

Marvellously detailed replies there. Having looked at the situation, the hose size is not that relevant after all.

I have a hose coming out of the back of the head with a nice alloy blanking plug in it.

I have no OEM H&V setup at all.

I have S14 throttle bodies rather than the original manifold, which means modified water connections at the front of the head, meaning the heater return has nowhere to connect to.

So

I have ordered the heater setup with 13mm hose as standard. Will get some 13mm hose barbs from machine mart, get a hole drilled and tapped in my alloy plug so one can fit in there, then drill a hole in the top of the radiator and fit another barb in there, maybe get another bit of more substantial metal threaded and solder/epoxy it to the head, or just reach in with long bendy tools and get a nut on the inside.

Debated heater control valves etc, but I think I'll fit it with no off valve for the time being - any trackdays I get to in the near future will involve heat/demisting!

on injected m10 engines there is a metal pipe from the waterpump to the hose for the heater that sits under the inlet ...could this be the answer ..have look at the pic in the link..edd
http://77e21.info/photogallery/stroker/ ... lled_2.jpg

Cheers Edd

I had assumed the heater pipe went to the housing at the front of the cylinder head. Looking at that and realoem reminds me that the pipe off the back of the pump has a y adaptor in it, one goes to the manifold, the other presumably is a heater pipe. Presumably that's the return straight into the pump, I believe the feed to the heater is the one from the back of the head.

Unfortunately the slug is wedged in my garage and there is no way I can get under or even to the inlet side to look. Also have a skip on the drive so I can't push it out at present. However sticking fingers in there I can feel something coming off the back of the pump. If I have another blanked off hose in there I can connect to that as well and leave the rad intact.

Anyone have further thoughts?

Jim

two photos of my injection engine in recks old car(engine swap part 3......) on face lift cars the heater valve is in the hose to the back of the head. .hope these pics help jim