My search for POWER!!

A Honda CBR600 head would really liven it up ;D
Fits the 1098, I'm not sure if the more common BMW K1100 head does.

...I don't really have any useful suggestions I'm afraid. But something for you to think about ;D

For the best power per pound, fit a cylinder head of a 1275 metro, HIF44 carb and inlet manifold off a MG metro with K&N filter. Had that setup on my 998 metro along with a Maniflow lcb manifold and exhaust, really livened it up and would do 80mph all day long. It you want to go a step further fit a camshaft from a MG metro and a distributor with a modifed advance curve, should give you a good bit more torque as well then.

Yep certainly is effective. It's the mainly the cylinder head that restricts the small bore engines (998, 1098) as they have the closed type chambers and small valves, so fitting the larg bore head will liven it up a fair bit. Forgot to say though, if you do want to fit a MG metro camshaft, you would have to recess the exhaust valves into the head about 1-2mm, as the exhaust valves of the large bore head overlap the small bores of the 1098 and will hit the block if not done. It's an easy job for an engineering company to do though.

Not sure tbh, never had experience running a weber on an A series engine, have read that people have had good results with them though. The standard 1.5" SU would still perform well on that setup along as you fit it to a decent inlet manifold and use a K&N filter, a HIF44 (1.75") SU just gives more top end power and my 998 engine was more responsive with one fitted.

Nausssssssssssssssssssssssssssssssssssssssssssss.......

;D

Before you kick off, you really should have a long hard read through David Vizards book - How to Hot Rod Your A Series. If you don't have it, buy it. It's worth every single penny. And then some.

I never knew the 1275cc head would fit a "small block" Mini. I always thought they were about an inch or so longer. But comparison of head gaskets would answer that one anyway. As far as I know the only difference between the 1098 and 998 was a long-throw crank. So the 998 will rev harder but the 1098 would be torquier.

The biggest secret with my 1380A+ are the valves. They're standard Mini Metro Turbo A+ valves. The ports are huge, the combustion chambers are cut back as far as possible, the pistons are really high compression. But the valves are standard and supposedly "tiny". But that little bit of restriction makes for monster air speeds into the chamber. Think of it like putting your thumb over the end of the garden hose. Big air speed is how I can get a big cam to work at 1500rpm, not 4000rpm like it's supposed to. It does lose out at the top end (she runs out of puff about 6500rpm), but it makes frying tyres easy. It also pushes the Morrie to 220kph (so far).

If I was going to do up a 1098 on the cheap, I'd start by putting a respectably big cam in the 1098 and porting the head. Try to make the ports large (they are horrible standard) without lowering the floor too much. Aim for a shallow angle between port and valve. Cut down the valve guides (a bit, not remove them completely) too. De-shrouding the valves is a good idea, but you'll lose compression unless you shave the head/drop in high compression pistons to compensate. While you have the grinder out, dowell the head and intake so you can port-match them. But don't do that to the exhaust. So at this point, all you've shelled out for a Dremel (or similar) and a cam kit.

Now, before you do anything else, drop the head back on it and take it for a drive. Try the combo of small valves, lots of porting and larger cam for yourself. If you like it, keep it. If it's too restrictive, then take the head off it and go up in the valve size. It'll only cost you one head gasket more that way - and if it all goes according to plan, you'll end up with a really driveable car. I know this advice flies in the face of everything everyone has ever said about getting horsepower out of cars, but this is a road car, not a high-rpm screamer race car.

As for the Webber, you've got it, use it. My personal preference would be for a single 1.5 inch SU. My 1380 runs as sweet as a nut on a HIF44 1.75 inch SU.

But aside from all that, remember that at the end of the day - it'd be cheaper and more horsepower laden if you started out with a 1275...