Twin HS2 heat shield position? Cooper S MK2

[minstix]

Hi,

Here's a question that I seem to be going round in circles with. I'm fitting my refurbished original to the car twin HS2 carbs to my Cooper S MK2. The question is in which order should the parts be assembled onto the manifold?

The manifold is fitted to the car. Should it be:

'Heat shield-spacer-carb' in that order or should it be "spacer-heat shield-carb?'

I've had equal number of people tell me it should be one way or the other. Anyone any thoughts on this?

Thanks,

Steve

Heat shield next to manifold_.jpg

[richardACS]

I would say the second image appears more balanced - I could check on mine a bit later....

[Peter Laidler]

I agree, otherwise the rearward step in the heat shield takes it very close to the manifold from memory

[andy1071]

I thought the spacer was an insulator, therefore picture 1 seems more logical..?

[Ronnie]

Parts lists show stacked abutment brackets next to manifold as photo 1 so heat shield would be the same.

[richardACS]

I would say the second image appears more balanced - I could check on mine a bit later....

Have just checked on my Mk 2 S and it is configured as per image no 2...

[minstix]

I have just temporarily put it together as a trial (without tightening any nuts) trying both options and offered up the original solid metal fuel pipe that runs between both float chambers. There's a bracket on the pipe to the right that bolts through a hole on the right hand heat shield. Then there's a smaller bracketon the same pipe that screws to the same place the throttle cable mount is attached to, which is screwed down to the top of the manifold.

If screwed to both locations when the set up is with 'spacer then heat shield,' ie picture 2, the pipe gets a bit of a bend in it to accomodate. If when the heat shields are 'straight on to the manifold' first, picture 1, then the spacer, the pipe will run straight. So I'm inclined to think that's the way it was intended. But I could be wrong.

Anyone any further thoughts?

Thanks for your help,

Steve

[Polarsilver]

Suggest you trial fit with the exhaust manifold that you are using . my experiences with a Maniflow LCB the problem was the carb heat shield fouled the exhaust manifold .. solution was Heatshield needed to be located the carb side of the spacer but then ran close but clear of the Float Chambers .. this set up has never been a issue with the car in use.

[richardACS]

Have just checked on BMC AKD 3509 and it appears that the spacer/insulator sits between the heat shield and the carburettor and therefore that would match what you are finding...

Unfortunately the schematic is not clear but does seem to match with your first image..

[Ronnie]

Pictures taken I/2 hrs ago I can vouch for the Mk 3 as being as factory position the Mk 2 was purchased much later but both as your photo 1. and Mk 2 is known to MCR and is purported to be very original.

[minstix]

I have fitted a new Maniflow LCB manifold and yes, if the heatshield is fitted as in picture 2 it comes very close to the cross bar of the heat shields. It doesn't actualy touch but is close, there's about a about 2mm gap between them. Probably not ideal bearing in mind how hot the exhaust manifold will get.

I've tried spacing the bar away from the exhaust manifold using extra nuts as in the picture. Picture 1 is a bit misleading as it looks like there's two nuts on each side but it's the reflection in the gloss paint. I just fitted one nut and a flat washer either side in between each heat shield and the cross bar. It's given a significant bigger space between the bar and the manifold and there's still a decent amount of space between the bar and the bodywork. Hopefully it means the solid petrol pipe should fit correctly now.

Thanks for your input everyone, much apreciated.

Steve Hills

[Ronnie]

I have fitted a new Maniflow LCB manifold and yes, if the heatshield is fitted as in picture 2 it comes very close to the cross bar of the heat shields. It doesn't actualy touch but is close, there's about a about 2mm gap between them. Probably not ideal bearing in mind how hot the exhaust manifold will get.

I've tried spacing the bar away from the exhaust manifold using extra nuts as in the picture. Picture 1 is a bit misleading as it looks like there's two nuts on each side but it's the reflection in the gloss paint. I just fitted one nut and a flat washer either side in between each heat shield and the cross bar. It's given a significant bigger space between the bar and the manifold and there's still a decent amount of space between the bar and the bodywork. Hopefully it means the solid petrol pipe should fit correctly now.

Thanks for your input everyone, much apreciated.

Steve Hills

Can you not turn the bridge piece around so that the angled flange is towards the bulk head

[Dr.Mabo]

Change the carb spacer and the heat shield and problem is solved.

Installation sequence: inlet manifold > spacer > heat shield > carb

[Cammsjb]

Hi all,
This is how my carbs are set up on my 69 MK2 S & also fitted with a Maniflow LCB manifold, no problems fitting/clearances.
Heat shield-Spacer-HS2 carbs.

Hope this helps Steve.

John.

IMG_2907.jpeg

[Peter Laidler]

The reality is that so long as there is clearance around the parts that matter....., no rattles or chafing etc etc, then it doesn't matter a jot which order that it's assembled. That's because whatever order it's assembled, the front face of the carb flange always remains the same distance from the inlet manifold.

I've got my doubts that the insulator is a thermal barrier*. It's just a spacer
(* it might...., but it won't act as a thermal shunt as in an insulator)

[Allen Brzeczek]

I have the original HS2 manifold and carbs from my early 67 S still assembled as removed from the car, I am using an alternative 1380 engine etc and have retained the original engine and ancillaries to re-fit to return the car to standard at some later date.

The order from this is manifold, heat shield, spacer then carb and obviously relevant gaskets in each joint.

[minstix]

Hi everyone,

All very helpful, thanks. I think Peter is right in that in practice, it shouldn't make any difference which way it's assembled. I was just trying to put it back together the way it left the factory. Looks like that was Manifold-Heat shield-Spacer-carb. Of course it didn't have a Maniflow LCB exhaust manifold when it left the factory. The original manifold was last seen in mt ex wife's loft 35 years ago bit that's another story!

I've noticed that if you buy a new heat sink kit from Mini Spares, it has a modified cross bar to allow more space.

Steve

[minstix]

Thinking about it, yes, you probably could just turn the cross bar round.