I understand that water heated inlets result in a quicker warm up etc but are they worth it from a power point of view? I would have thought that there's already enough heat around the Rossa engine bay without heating up the inlet as well!! When I was tuning my Subaru to give massive power one of the tricks was to fit tufnel heat insulating spacers between the inlet and the head to stop heat transfer so a heated inlet on the Rossa (MG1275) seems counter productive Any opinions out there?

Leave it off. As you say its for warm-up and economy, I do'nt think you'll suffer from the carb icing up Do'nt fotget the heatshield, as you say heat is your enemy particularly with the mid-engine bay. I ca'nt remember if the carb spacers for the large SU's are plastic (phenol?) but that would help. If there's enough clearance to use 2 spacers then do so, that can help power too.

Leave it off and try it. If it does ice up you can always re-plumb it. I always had mine water heated as I had very bad icing problems on a Ford Escort engined Dutton Sierra many years ago so I have been wary ever since. That was front engined though with a flow of cold air in through the grille. The Rossa doesn't suffer from a lot of cold air flowing through the engine bay.

Thanks guys. As far as I know none of the A series inlets were heated as standard and I never had any bother with the Minis I owned in the past. I just wondered if I was missing something because all the tuners seem to supply them heated as a matter of course. Good point about the heat shield - there isn't one on the car A cold air inlet for the carb would be helpful too but I expect that it would mean a remote mounted filter - something else to keep me from getting bored I suppose

All of the A series inlet manifolds were heated as standard. They were cast as one piece with the exhaust manifold so they got far too hot for best power. The MG Metro manifold was water heated as standard and so are most 'go faster' manifolds. This is because they actually run cooler than the standard manifold and so produce more power.

Ah yes..of course - the famous A series inlet hot spot I had forgotten about that and was thinking more about the twin SUs that I used to fit. Interesting point about the inlet running cooler - does that mean that it's water cooled rather than water heated?

Definately heated Interestingly the only water heated manifolds seem to be for the single SU. I've never connected the pipes up, in fact i usually cut the pipes off to tidy things up a bit.

personally i would take the technical approach,

Sort out a thermocouple and try to replicate two simular engine bay conditions, and measure the air intake temps in teh man ifold with an without the cooling circuit plumbed up as it may actually remove heat, seeing the inlet manifold is nice and conductuve conducting all that lovely heat fromt eh exhaust manifold,

Thats what i would do get technicall

WEST

There's no way it'd remove heat - on a hot engine you can touch the inlet and it's barely warm if it's a seperate one - if water heated it'd be up around 80 degrees so touching it would be uncomfortable.

It adds heat as Phil says, the idea was for economy as was the hotspot.

That's it then....I'm not going to plumb it in and will probably cut the stubs off too - you're a man after my own heart, Tim As a matter of interest I emailed Mini Spares (who made it) and asked them for their views - I'll let you know what they say if I get a reply.

I wouldn't cut off the stubs till you're sure you don't get icing problams on a cold freezing foggy day. If not then go ahead but I wouldn't remove the option till you're sure you'll never need it.