I think it has been overlooked that the MG Metro water heated manifold flows very well. If you read Vizard's books he comments favourable on the flow rates of this manifold. So there is a flow rate benefit to fitting it in addition to having more stable inlet air temps.

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But he's thriving and striving and hugging the turns.

I run one of these manifolds connected and have not had a problem at all, in fact the bloke that built my engine [Ron Williams] has been using this manifold in this fashion for years on untold amounts of cars without problems so the recomendations must start there.

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That's why it's good to be.............ME

There never was a problem with the manifold. As someone said it actually flows better than the usual cast iron versions.

You just need to decide if your carburettor is freezing up or not. If it does, than connect the heater hose up through the manifold.

If it doesn't, then you may be heating up your intake manifold pointlessly. This may lead to power loss if you reason that it causes air density to go down by heating it, or it may be so inconsequential because of the velocity of the air passing through that it causes no issues at all. Any one got a dyno and some time to kill?

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

If you want something you can turn on and off, go to the wrecker and find a heater tap and control cable/dial of the same size to suit the hose you are using and connect that into the line, it wont matter if it is before or after the manifold. This will allow you to run it at half or whatever, if you want you can "tune" it to the conditions.

What is the likelyness that the manifold is actually being cooled by the water passing through it? The manifold is attached to the cylinder and sits between three exhaust ports so has the potential to get VERY hot.

I'm thinking it could be referred to as a 'Temperature Controlled' manifold rather than Water Heated/Cooled?

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But he's thriving and striving and hugging the turns.

Maybe there is an element of spot cooling but a mini has a lot of frontal area and the air has to go somewhere when the car is moving. Much of the air goes over the motor and down between the engine and the firewall.

I would argue that this has a far more noticable cooling effect that the spot cooling of a 90 degree C water.

Like an 'Oil Stabilizer' heats/cools oil on a car, maybe you could call it a 'Manifold Stabilizer'

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

back to the intake thingo though, i'm not sure if this bigger intake is as good as the smaller one i protoyped, i'm gonna record how far i get on a certain amount of litres then change to a smaller one and see if there is a difference.

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Sunday Morning Mini Sprint http://www.youtube.com/watch?v=UtGuzqBQ32Q my "rendezvous"

There's quite alot of physics involved with intake runners. The long and short of it is that a long narrow intake will lead to reduced airfolow at higher RPM. Look at a bit of ram tube theory in Vizard to get a better idea.

But if it works for you, then hey why not? Getting cold air to the carb is something the performance boys have been doing for years.

That picture is still a corker though....

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

when everything is done i'll dust of the black spray can.

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Sunday Morning Mini Sprint http://www.youtube.com/watch?v=UtGuzqBQ32Q my "rendezvous"