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MG Midget and Sprite Technical - New LCB Exhaust On... Heat Shield Clash...


Evening all,


I'm new to these forums. So along with an hello, I shall ask a question that has stumped me today.

I have just fitted a new LCB 3>2>1 exhaust system to my '73 RWA midget. The system when on okay with only a bit of tailoring needed for the rear hanger.

Today I refurbished the HS2s. After they were both nice and sparkly it came to the re-assembly business.

The thin heat shield that sits between the manifolds and the carbs clashes with the centre down pipe from the exhaust manifold.

This leaves me with several options;

1) Cut out a hole for the centre down pipe to poke through.

2) Mount the heat shield on the other side of the black plastic spacers and then cut a slot for the throttle linkage bar so it doesn't clash.

3) Form a new heat shield with a lump in the middle to clear the exhaust manifold.

4) Run without a heat shield.


Any advice/suggestions most appreciated.


Sincerely,
- Richard
R L J Oakley

Richard,
I think there are supposed to be two phenolic spacers between the heat shield and the manifold. These would move the heat shield out away from the manifold, and giving the required clearance.

Oh, and Hi and Welcome !

Guy
Guy Oneandahalf Sprites

Thank you Guy.

That was my point 2). Apologies if I did not word it well enough.

The spacers were between the shield and the carbs before I took it apart. If I do mount them between the manifold and shield then the throttle linkage bar clashes with heat shield. Rather Catch-22 at the moment.


Sincerely,
- Richard
R L J Oakley

a very common problem, almost all LCB manifolds foul the shield; usually folk cut a lump out of the heatshield, you might need to run a stiffening bar along the lower edge where the springs attach, to stop it going all floppy.
David Smith

Sorry Richard; My mistake for not reading your message carefully enough before diving in with my reply!

Problem with #4 is that you need somewhere to attach the linkage springs to! Maybe there is an option #5 if you could find a second set of the spacing washers and fit the heatshield with them on both sides.

Or option #6 which is to fit a single HIF44 !
Guy Oneandahalf Sprites

Sorry Richard but I have never had any vapour lock problems and have never fitted a heatshield so can not really say what would work and what wouldn't.

However if I were in your position I suspect I would do go for number 3 or at a push number 2

Good luck mate.
Robert (Bob) Midget Turbo

With either 2 or 3 it would pay to check whether the linkage will clear. Simplets way would be to do a trial fit leaving the heat shield out all together so you can see how much room you have between lingage and centre branch.
Paul Walbran

Thanks for the replies gentlemen.

I am thinking I might purchase two more spacers. This method would require another pair of gaskets to be used so yes, an increased possibility of leaks, but I think it's preferable at the moment over having an Emmental heat shield.

Does anyone foresee an issue with clearance to the N/S wing and/or bonnet? I will have to purchase longer bolts but I am hoping that would be quite an easy source?


Regards,
- Richard
R L J Oakley

Richard,
You could offer up one carb to check clearance, using the two spacers. It may well depend on what sort of air cleaner you are using.
Guy Oneandahalf Sprites

When we had the same problem and tried double spacers we did have a clearance issue - with the bonnet I IIRC
Paul Walbran

Richard see my first post - many of us have been here before; the solution that works best is to cut an oval-shaped chunk out of the centre of the heat shield - size dependent on the exact curvature of the centre exhaust pipe.
David Smith

Richard

I had the same problem too. Simply solved by bending the heat shield just sufficient to obtain clearance - mine is stainless steel one so bending took some effort. I'd be reluctant to cut a slot because it negates the purpose of the heat shield in the first place. That said, I have seen some shields advertised that do have slot and a bar across the bottom with holes for the springs.
Peter B

I used double spacers and a small ally sheet to protect the float/jet areas; easy to bend in situ; fixed on the carb lower mount bolts.

A
Anthony Cutler

The other option I've seen used is to fit the Mini Cooper/Cooper S shields. These are designed to fit with a LCB type exhaust and are basically in two halves with a link bar across the bottom for the spring fitting.

Stu
S J Simons

This thread was discussed between 13/11/2010 and 21/11/2010

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