Bear in mind it is sitting directly above the centre branch of the manifold, which can and does get red hot...
Alloy is way more durable here than phenolic, or any plastic.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

yes not cheap & you can imagine how much it would cost to have a run of 20x or 30x of them on the CNC machine

alloy is often less expensive than plastic funny enough

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Just revisiting this thread to find out the outer dimensions of a regular 1 1/2 carb inlet flange. Im planning on making a spacer block too.

I know it is 38.1mm at the carb opening and 9mm/12mm bolt holes or whatever, but what is the maximum lengthXwidthxheight of the block I need?
I'd guess something like 15x7cm? how high can I make it? is 1 inch too thick?
Does anyone know a rough size off the top of their head? I can always cut it down...

If you mean the outside shape? I have a pair of alloy ones here that have been created to exactly match the size of the gasket and no more.

There's a gasket template in the how-to's you can print off in A4 if you don't have one handy. This will give you the dimensions.

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SooperDooperMiniCooperExpertEngineering

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

Just found it, Awesome, thanks!

Hi

on spacers, (alloy/alum Vs phenolic type), my thoughts were spacer is there to
a) avoid hanging up on extractor etc.. ie space it out
b) add some length to the induction side... better for atomisation

but are they also supposed to
c) stop heat transfer ????? think icing up and old water heated style manifolds (possibly why phenolic)
d) create heat sink, (possibly why alloy etc), but would gaskets interfere with this theory

if a and b are correct? then why dont you see more on the smaller carbs, ( i mostly only hear about the hs6.. is that down to inlet manifold shape?)

No idea what they are reeeeeally for, but I know I need mine because I have an original manifold which has been cut in half to use the inlet bit, so my 1 1/2" hits the extractors otherwise as mentioned above

They certainly do stop heat transfer. I have 1/2 inch phenolic spacers on the twin 1.5s I have put on my car.
After a long run through the country the carbs will be nearly ambient with the only heat in the carbs coming from the heat transfer through the mounting studs and nuts.

I'm not sure how this translates into performance, but would imagine a bit of heat would be useful in winter down here in the southern alps to keep ice from forming?

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SooperDooperMiniCooperExpertEngineering

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

As I understand it, that's why the mini originally had the exhaust manifold attached to the inlet. Carb icing was an issue in England, so the exhaust is used to heat the carby up. Not so much of a problem for most places in Australia though.

I believe you want cold air to the carby and a hot mixture to the engine for performance.
Phenolic stops the carby heating up which would be good in hot weather but in cold weather, alloy
would be better to help prevent the icing that Irish mentioned.
Tough if you live in a place that has both extremes.

*enters*

*suggests a stack of 20 or so gaskets*

*salutes*

*exits*

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Plus a shirt load of gasket goo

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1967 Cooper S - new front bearings to do.
1965 Cooper S shell - Slow progress. No time or money!
1966 Deluxe- next rustoration!
Mk 2 & XJ6 Jags. Less said the better.

= freshly bent carby flange...

As for the carb icing, I sometimes get it in my 45 Dellorto if cruising at 110KMH or higher. Carb is bolted straight on, with no wussy soft mount kit. Next time the manifold comes off, it's getting a bit of alloy tube TIG welded across the back of the carb mounting flange, and I'll plumb the `matic heater through it..
It's fine running at 100KMH.. but that's a pita on the freeway.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

i had some 1cm thick plate of aluminuim in the shed, so i banged up some spacers, in half an hour just use a drill. drill around a circle, then jigsaw (with a wood blade) then use a sanding wheel and sand out the spikes left between the drill holes, voila, cheap n no machining or laser cuting, also 1.5 carby spacers are hard to find in phenolic, for me anyhow.

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1969 Blue Mini K, 1330cc, Weber 45, polished aluminum roll cage, Race seats, 4 point harness, full rewire incorporating 8 fuses, 6 relays and new headlights just needs tyres front shocks and a windscreen til re-register