1098 4-speed to 5-speed

[Chipper]

AFAIK, he fitted a 12G940 (1275cc A-series) head to it, and probably some other mods, I shouldn't wonder.

[amgrave]

To quote BMC

"it has a 940 head which I have cleaned up in the valve throat areas, especially the exhausts which are very tight. The ex valves sunk by 40 thou for clearance. HIF 38 SU on an unheated alloy inlet manifold, both carb and manifold cleaned up more or less as per the Wizard, and AAA needle used with KnN air filter. Also a slightly larger bore exhaust, with straight through Cooper S silencer, and modified MG 1100 ex manifold to make it fit ... So NOT an LCB which is only any good with a hotter camshaft. Very essential crankshaft damper ( or the crank WILL snap ) and Duplex Gears. I reckon 60 / 65 bhp, but at decent revs of course, although should never be taken much above 6000. It works well with the 3.7 final drive"

You don't have to do it all though just fit a better carb on an alloy inlet manifold with K&N filter a 12g940 cylinder head noting the above and the crankshaft damper pully. This will increase the power output enough for a 5 speed box or 3.7 diff. I will be doing the upgrades myself later this year. If you want a chat about it I will be in your area Saturday 19th march around 11am.

[John Naylor]

Would love to, will you be in your Minor? Will PM you my details.
John

[amgrave]

Hopefully in the moggy but only if it's not raining

[warb21]

Again, all useful thanks.

What's the difference between a 1275 Marina and 1275 Midget engine - in terms of reliability/performance.. or is it so negligible I wouldn't notice?

[bmcecosse]

Midget engine may have the 'big inlet valve' head - and the Midget engine is much easier to install provided it comes with the original flywheel and clutch. Also has the correct front mounting plate to allow it to bolt straight in to a Minor.

[Chipper]

Midget engine also used better quality parts, e.g., a tuftrided crank as opposed to a plain cast iron one such as used in the Marina.

However, if you drive at normal speeds, I doubt you'd notice much, if any, difference between the two engines, in terms of power and torque, since both were similarly rated.

[bmcecosse]

They quietly dropped the Tuftriding after a while......