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MG Midget and Sprite Technical - Heater hose question for D Plumb

I'm trying to convert my heater hose connection from the bottom to top hose and wondered where Mr D Plumb got the hose from in the photo below. I can do it with all sorts of connectors and hose clips but I'd prefer a neat one hose solution like the one shown. Cheers!

John Payne

Photo:


John Payne

I was interested in this from the previous post John , I was trying work out if a cut down bottom hose would work
Mike Fairclough

Yes, just looked at that tonight but I think the angles are wrong. I've been running with mine into the bottom hose for years without any issues but I now need a bit more cooling and could see the reason why this would be better from the previous thread.

Might have a look again at the bottom hose option, even if I can just use the T piece it will help.
John Payne

I used a Mini bottom hose with a vertical flow rad. I *think* I may have used the same with a crossflow, but I can't be sure.
Dave O'Neill 2

This is what I did with mine using a standard vertical flow hose although it is silicone.


Martyn Wilks

Sorry should have listed what parts I used,

I made a -6 outlet from the head then used a 90° Goodridge 811 connector along with a piece of 811 hose I had left over from the internal fuel lines - this hose is PTFE lined and can be bent into very tight shapes as it is convoluted.

I then made a stainless steel adaptor that was BSP on one end and a barbed diameter to accept the existing heater hose outlet.

I then used a straight BSP to male -6 adaptor and a straight Goodridge 811 connector to finish the installation.

I attached the 811 hose with two stainless steel half saddle clips which secured to the rocker cover with button head socket screws.

The standard top hose heater outlet ran very close to the exhaust manifold so I shielded it with a Lava boot cover which is rated for 920°C continuous which I tested at work with a burner (we blow glass so I have access to very powerful burners) and it passed with flying colours.
Martyn Wilks

Martin, I'm only on my phone at the mo so your photo is very small but it appears your heater take off goes into the bottom hose as normal?

It's very neat wherever it goes though!
John Payne

Hi John, yes sorry it is off the bottom hose, just away from the water pump
Martyn Wilks

Just spotted another error should read Goodridge 90° not a straight connector - I was going to use a straight but then changed my mind
Martyn Wilks

John
Whereabouts is your other heater hose connected to the engine
I'm a bit concerned that fitting the return to the top hose instead of the bottom will bypass the thermostat and effect the proper operation of your cooling system
willy
William Revit

Thermostat? What thermostat? ;o)

Blanking sleeve fitted.

This is the (trimmed) Mini bottom hose...




Dave O'Neill 2

Question?
Many people say you must have the heater out let connected to something,i.e. Heater/ leading back to one of the hoses, or else No.4 cyl will overheat. this is something I have never understood as when I fitted my metro head I am sure I had to drill the point at which the heater tap is fitted. On other vehicles fitted with the A series engine, early ones had no heater and the later ones had an on/off tap controled from inside the car. Consequently during the hottest months the heater was off why did'nt siezures happen
Does overheating No.4 cyl only happen when racing, or is this a myth?
The only time I can remember overheating any No.4 cyl was in the Middle East when the LandRover dealers took out the thermostats as a matter of course and I had one sieze a piston,which I made them repair under warranty. I put thermostats back in the other 12 vehicles and never had another problem.

discuss

Mike P
M J Pearson

The car had raced in both the midget & Sprite Challenge and AHC series when I bought it for track day use. The hose was already fitted but I recall the vendor saying a batch of the spcial top hoses had been made presumabely for a group of racers.

On my road Midget in summer, I bypass the heater by connecting the outlet tap on the head to the return to the standard bottom hose to reduce the radiant heat in the cockpit.
D Plumb

Picture of crossflow bottom hose overlaid on standard top hose . Looks like it would work


Mike Fairclough

Thanks Mike F, looks like it might work, I'll dig one out and give it a go.

Thanks D, looks like I'll have to get one made if I don't find an alternative.

I must admit I've always wondered about the 'never turn the heater tap off' thing. The Metro didn't have an outlet at all at that point on the head and didn't suffer any problems. The reason I want to try it is that as was pointed out in the other thread, it seems wrong to be pumping hot water from the head into the coolant inlet. Plumbing it into the hose that goes back to the rad seems right.

My car has always run nice and cool, around 70-80 degrees C. But since I've started doing longer runs at constant high revs it is more like 80-90. I'm changing the stat to a 75 degree so thought I would try the hose swap as well. If those things don't work then I'll go for the blanking sleeve and finally an ally rad as last resort.
John Payne

You shouldn't need an ally rad. A lot of the time, I had to add tape to the rad to stop it running too cold.

I could do 45 minutes round the Nordschleife without cooling issues.
Dave O'Neill 2

No I'm hoping it will be ok Dave. It's just a bit borderline at the mo so I'm hoping a few tweaks will do the trick. I think it's a case of heat building up because if anything it runs a bit cool at times. I don't think the oil temperature helps as that gets very high as well so I'm going to drop the pressure a bit. Even when hot it gives about 70psi above 3000 rpm so I might try and drop it to 60. I'm hoping that the combination of a few small changes to both systems will result in overall lower temps. If not then it's big rad and big oil cooler time!!
John Payne

This thread was discussed between 08/08/2017 and 09/08/2017

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