7 replies to this topic

[whistler]

I have a 1275 A+ engine which has a head with the heater valve takeoff blanked and the heater pipes running from the bottom hose to the heater and back through the thermostat housing sandwich.

I'm fitting a different 12g940 head (original one cracked) which I believe is from a 1990 Cooper/RSP. This one has the heater pipe takeoff on one end of the head and a thermostat sandwich takeoff on the other end. All the water holes on the head face are open (the original head had some closed) so do I have to use the pipe connections on both ends and cap the bottom hose take off or blank the sandwich plate connection and use the bottom hose. I'm concerned that if I don't use the far end hose take off and blank it off that I'll end up with uneven cooling and hot spots. This head has no bypass either so I'll be drilling the thermostat and capping the water pump connection.

There is an inline heater valve for controlling flow by the bulkhead so that is not an issue.

Need some experienced input here.

Hope this makes sense to someone as I'm a bit stuck. Neither Haynes or Vizard are much help on this subject.

[whistler]

Hmm. 35 views and no answers. Have I asked a stupid question?

[1968andyf]

Feed off either heater outlet or sandwich plate block off the easiest and feed back into the bottom hose

[phil hill]

You have one of four options:

 

1. Buy/make a blanking plate for the heater tap hole at the end of the cylinder head and use the original heater arrangement with the sandwich plate.

2. Using a heater tap or stub-pipe with suitable hose connected to the heater tap hole at the end of the cylinder head and do-away with the sandwich plate pipework.

3. Using the unique lower radiator hose for the HIF carb Rover Cooper and the stub-pipe and hose connected to the heater tap hole at the end of the cyliner head and routed via the water heated inlet manifold (MG Metro type as used on the Carb Cooper ) you can retain the heater take-off from the sandwich plate and connect the original heater tap to the bottom hose via the water heated inlet.

 

There is yet another variation:

 

4. Connect the heater tap to the cylinder head, plumb to the heater as usual.  Using a T-piece connect both the short hose from the sandwich plate and the return from the heater to the radiator bottom hose.  This has the benefit of effectively replacing the function of the original bypass hose when the heater tap or valve is closed, but allowing hot water flow from the cylinder head to the heater when the heater is required.

 

Phil.

[whistler]

Thanks Phil and Andyf,

Just went out to take some photos of both heads and realised I should have put them alongside each other before I posted. The 'new' head has the waterways blocked with brass plugs and the 'old' cracked head with small core plugs. So my mention of waterways holes being open is a load of bollards, sorry to all the readers; I'm having a very senior moment.

 

I'm going to blank off where the stub is and use the sandwich plate and bottom hose for the heater.

 

Perhaps I'll think about my perceived problems a little more before asking questions

[phil hill]

Hi there.

 

I hope you don't mean that all the waterways in the head are blocked off with brass plugs, but rather that there are some brass plugs with holes drilled through them.  The waterways (from memory........) are plain holes drilled into the cast iron, and the oilways are drilled into brass inserts in the head. 

 

Phil.

[whistler]

here's a picture of my b..gered head showing the 3 blanking plugs circled. on the 'new' head these have brass plugs instead and that's what threw me.

Attached Files

•  DSC_0020.JPG   81.65K   6 downloads

[gazza82]

My 12G940 head has one brass plug in the centre one you marked but the two end holes are steel on mine .. no plugs or marks.

 

I think the water ways are the three larger holes below the combustion chambers in your picture. The oil ways the two brass plugs with holes at each end.

 

Looking at Des Hamill's book, you might find that you can tell the oil ways by the head gasket (although I think he shows the BK450). These seems to have brass edges so the eight along the top edge either side of the plugs may also be oil ways.

Edited by gazza82, 15 April 2015 - 01:38 PM.