Article on The Internet Mini Encyclopædia
Before you remove anything... ensure you are happy that you have any tools or parts you may need to complete the job (can you jack the car up high enough and safely enough to get access?) ... REMEMBER you are effectively about to take your car "out of service".... exhaust mounting rubbers can rip, manifold-to-head and manifold-to-carb gaskets can be damaged (you should really renew them) and as they say in Stingray...
"Anything can happen in the next half hour!"
Ensure you have manifold studs that are short/long enough for the new manifold with your OLD carb.. remember some studs are UNC (coarse thread) one end and UNF (fine thread) the other.. check your new manifold is threaded the same! ( threads in aluminium are commonly UNC)
Is there is a heat shield or heat insulating spacer?- remember it is there to keep the carburettor (full of petrol) away from, and/or protected from, the hot exhaust likewise the fuel and other lines tothe carburettor.. put them back right.. away from the heat of the exhaust and NOT kinked....
Ensure the manifold flanges you are holding down are the same thickness as each other OR find some way to accomodate the differences between the OLD and the NEW (this would be so easy at the show if MIG welders and angle grinders grew naturally on bushes and were fertilised with rotted down copies of the Mini Haaynes manual)
.. there is nothing like a good air leak for "running on" or "running lean"!
Ensure you have rubber exhaust mountings that all fit where the old ones fit (some cheap ones supplied are pattern parts and DON'T fit on GENUINE subframes - like some seen on the RivRun... check first, you might DESTROY the old ones by accident removing them), however YOUR subframe, if a pattern one, may have the wrong shaped/located holes and the new ones might be spaced ok for REAL Mini subframes?.
Ensure the exhaust clamps are right, you have some exhaust sealing paste to hand too...
Ensure you know where to jack the car up safely so you don't rip out an engine mount and then find no one has new ones for sale and have to drive home with an engine 3" too high (and twisted 2" forward) at one side ;).
If you are embarking on a long drive in a vehicle that is effectively being driven with a loose engine, be prepared for interest from the police. They might not know you are using non genuine wing mirrors on your "Mini Ritz" but they do know how an engine is supposed to fit under, and not proud of, where the bonnet is supposed to be...
Don't expect a car fitted with a better breathing exhaust and inlet manifold to be in an acceptable state of tune when this is all fitted up and your fuelling is not adjusted accordingly.. even if it does run you might return home with a cooked engine and burnt out valves. If it "runs on" when you turn it off, find the air leak around the manifold to cylinder head join or suspect very lean running ( you might get white spark plug tips and overheating too).
Expect to have to "make good" your rush job when you get home, exhaust/manifold fitting is not easy to get right.... mess up the job in the field, drive x hundred miles home and you might just be doing a head rebuild next up.... ;)
It is far easier to take your pride and joy home WITH the bits in the back and do it at home (despite your car looks like a Mini/Abrams Self Propelled Gun hybrid on the journey home)........
.... or find 2 members of the I.M.E. team to assist ( but remember we work WITH you not FOR you while you play football or drink beer :)
Added by FB after returning from the RivRun 2003 having seen the results of a Kwik-Fit in the car park hurtling past him on the A30...
Join the Minilist share your joys and woes with 500+ mini owners worldwide via Minilist at Yahoogroups