Power upgrade - carb?

Post by **Wedding_Car** » Wed May 25, 2005 12:54 pm

Ok I've got the '61 moggy in the garage at the mo for a new headgasket, while i'm at it what can i do in terms of bolt on (with a little modification if needed) power?

Going back to my mini days the first thing i would do is slap on a HIF44 carb and water heated inlet manifold from a MG metro, is this the same for moggies? what about exhaust manifold, can i seperate the original moggy inlet from the exhaust manifold and reuse that?

Engine has already been changed to an 1100cc one (ray of leamington should be able to confirm that!)

Cheers
John.

Post by **Stig** » Wed May 25, 2005 2:02 pm

Well as you've already got the head off I'd suggest a bit of porting if you've got a suitable grinder and the inclination as the cylinder head is probably the biggest restriction. David Vizzard's excellent book should tell you all you need to know.

A bigger carb would help, but a HIF38 would be big enough unless you're improving the flow in the cylinder head. The MG Metro manifold should definitely help, but separating inlet & exhaust on the cast manifold needs great care - unless you're junking the inlet part anyway.

The standard exhaust system is restrictive - I got better power and economy after fitting a larger bore S/S system. You do, sadly, lose most of the characteristic farty noise when you lift off though...

Post by **Wedding_Car** » Wed May 25, 2005 2:14 pm

cool, loosing the standard tone isn't a problem really. I'd like to have the time to do some porting work but that's not going to be an option. I was more thinking along the lines of instead of bolting up the stock parts again (which are pretty tired) I'd go for and improvement.

What metros did the HIF38 come on?

As for exhausts are these available off the shelf?

Cheers
John

Post by **Stig** » Wed May 25, 2005 2:44 pm

I think all 1.0 Metro's had the HIF38 and all 1.3 Metro's had the HIF44 (different jetting for the economy models or the MG). The HIF44 would work if that's all you can get, I just think it'll be overkill.

My exhaust came from Grumpy -now sadly no longer trading, but ESM have taken over the stock. I got the tubular manifold as well, but you can get systems that use a Marina manifold I think. I'd guess various specialists would sell you something similar - have a look in the back of the club magazine. (whatdya mean you're not a member?!)

Post by **Wedding_Car** » Wed May 25, 2005 2:59 pm

Nice one cheers, looks like i'll be metro hunting at the scrappies this weekend then!

Post by **Alec** » Wed May 25, 2005 3:29 pm

Hello John,

as Stig says, the head is the thing to tackle first. A larger carburettor in it's self will not do much. There are alternate heads that can be fitted which will be more effective. There has been a lot of discussion here about alternate heads and what is required to fit them.

Alec

Post by **bmcecosse** » Wed May 25, 2005 8:52 pm

For a real improvement - fit a 12g940 head from a 1275 Mini engine. For safety - you should grind pockets in the block for the exhaust valves - i beleive they will hit if you don't - but various peeps keep coming on and saying they just bolted it on (1275 gasket!) and it worked ok. You also need the 1275 rocker gear - it's different spacing - but you can re-arrnage yours to get the same effect - it just take s a while. The MG inlet is ideal - but 1.5" carb will be plenty - but don't connect the water heating ! You want that mix as cold as possible. Obviously a better exhaust will help loads - this is where I am stuck with my car - trying to make a Mini lcb fit !!