recycling again

[max midas]

Yet another use for an empty tin can.
Last week I replaced the exhaust manifold gasket - AGAIN, only for it to blow 20 miles into a 200 mile journey to Lancashire.
I wasn't going to go all the way back sounding like a V1 bomber, but not knowing of a useful motor factors, I thought laterally.
Having ascertained that the flanges of my Ali inlet manifold are thicker than the flanges of the LCB, therefore not clamping the centre branch sufficiently, I decided to make a shim out of some thin metal sheet - a peach tin from the recycling bin.
With 5 minutes of tin-snipping, I had an C shaped piece of shim which went open end down over the centre branch flange, between the flange and the securing washer/nut.
Result - complete success!
In fact I'd doubled up initially, but found the inlet manifold a little loose with both shims.
I'd heard that an aluminium coke can is either 2 or 5 thou thick (I forget which), and when cut to shape can be used to fill the gap between the two centre cylinders on top of the head gasket if the head is a little warped. The steel can I used is a little thicker, but makes excellent shimage.

[Hans Efde]

I am looking at buying an LCB, and I wonder if this is a common problem of aftermarket LCB's? Or is this just one or 2 brands (or perhaps nameless) that have it wrong and can I trust a quality exhaust to have it sorted out properly?

[mikeeskriett]

It's common to quite a few LCB brands, the more you spend the better they are generally. The cheaper ones tended to just have plan flanges so you used to have the weld two washers together than cut one of them in half making a stepped washer to get the clamping pressure right. The more expensive ones have a spacer welded to the flange to make up the difference between the inlet and exhaust flanges. I have an old minispares one on the Bronze with no fixed spacers and the Maniflow one on the gold which has them welded on. It's a bit of guess work in terms of the spacer thickness the maniflow ones seem to be setup for the stock MG manifold but it's worth having a quick measure up before you fit it as it saves you time and gaskets.

The other tip is to tighten the nuts get the engine warm then nip them up again this method has worked for me for years and touch wood I've not had any issues with it since doing it.

[manifold]

another method is to file down the flange on the inlet manifold to match the exhaust. I never found an exhaust to match the thickness of the inlet.

[MrBounce]

Whenever I've had an LCB I have always filed down the inlet to sort it. First one I had on my 1275GT had stepped washer which were, to put it bluntly, rubbish. Dremel is your friend!