Manky Monkey Motors

Following on from previous threads regarding pipe layouts on Reliant engines.It occurred to me that the pipe from the rear of the head, that we connect back to the pump, sometimes via the heated jacket on the inlet manifold but usually not, may  actually be causing problems.
Reasoning being, that it allows too much bypass of coolant, (there is already a bypass hose) reducing the amount of flow through the radiator.
Flow through the rad seems to increase significantly with this pipe clamped.
I know a few have discarded this hose completely but I intend to restrict this pipe to reduce the bypass effect.
Any comments?

The hose to the rear is essential to circulate the water away from number 3 & 4 cylinders .
If the water is not circulated you can get a hot spot especially if there is a build up of hard limescale or casting residue left in that area .
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When the heater and manifold block are connected into this hose,the coolant must be pumping through the hose at the same  pressure? So why not leave it?On the other hand,maybe the flow slows down a bit as it runs through the heater etc?I know there is a fair bit of pressure in that hose,as it pumps with a fair old pressure into my exp tank.
 

Fifer, what happens in a Reliant when the heater is turned to cold?

Thanks.
Wondered if that might be the case, hence the asking for comments. I believe that on early engines the rear tapping was for the heater unit which when the heater was off would have no flow, but when the capacity was increased to 850 they did away with that system.  

You interupt the flow and the extra cooling achieved by the coolant flowing through the heater matrix is lost .
Long time Reliant owners either chuck the heater on/off assembly away or keep it in the on position all the time .
I launch the blighter as far as my arthritic fingers can manage and run with the heater on all the time .
I just use the inbuilt climate control fitted in all Reliants during the summer months .  ;D
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Im none the wiser ..."those to the rear is essential.." what does that mean?

I think fifer is saying that the hose from the rear tapping to the pump is required due to poor internal flow characteristics.
The manual is not clear about hose directions ( seems Reliant changed them around a bit) but it looks like they ended up with, hose from stat housing to manifold adaptor, hose from manifold adaptor to pump, hose from rear cylinder head to heater, heater to pump.(think that's right :-\)


A Reliant I looked at had a three port heater control fitted. So when the heater was off the matrix was bypassed. An owner modification I expect.

Result of typing without my glasses on  :-[ and should read ;
The following link to my site gives alternative hose layouts ;
Of course where the heater is shown that is now just a continuation of the hose .

https://sites.google.com/site/fifersrelianthintsandtips/water-coolant-stuff/water-hose-layouts

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is that a prob? it will get the chance to cool better?

Apparently not. My reasoning was, if there is too much bypass, all that might happen is, that too much coolant just circulates around the engine and not enough flows through the radiator, to be thermally efficient.