Marina gearbox

[jazz_devil22]

Hi peeps,

I know this may seem the wrong way round, but can you fit a marina box to a 1098 moggie engine?

what I am planning to do is put a BMW K100 DOHC head on my morris to try and get 80-90HP hence keeping the engine, but I would quite like to put an overdrive gearbox on, hence the marina gearbox.

feel free to tell me to go sit in the corner for being stupid.

Cheers

Jeremy

[Jefftav]

To my knowledge the Marina box will fit but Marina boxes never had overdrive or 5th gears fitted - unless you have something different as I thinkyou can transfer the internals of a spitfire OD gearbox into a Marina GB. Your options are standard 1098/1275 gearbox, higher ratio diff in the back axle, or 5 speed conversion which if you are going to the bother of the the BMW MIni head might be a good option.

[bmcecosse]

Welcome to the forum - and do keep us up to sped on the BMW head conversion - but I fear the 1098 engine is a poor weak thing (although late Spridget 1098 had larger mains) and you would do much better to use a 1275 engine for this conversion! In fact -I think you NEED the big bores of the 1275 to match the chambers on the BMW head. I think the problem with other boxes is in clearance from the chassis rails and the steering rack - the Ford 5 speed box seems to be the common upgrade - but not cheap.

[charlie_morris_minor]

If you want to go down the O/D route you need the output shaft from the triumph box and put the marina gears on to it.

I did it about 10 years ago and really liked it.. if you decide to go down that route please feel free to ask questions..

by the way it is not just the spitfire box the dolomite range (except sprint) is also a source of O/D boxes

[jazz_devil22]

rather than using a 1275 engine i was going to bore the current engine to take imp pistons and see what that does. The important thing is if i don't like it i can always change it for a 1275 engine. But hey, someone's gotta try it, it might as well be the idiot with way too much spare time

[bmcecosse]

If you can still get Imp pistons ??? Seems a hard way to go when the big bore engine route is well known. Snag is - the BMW head is designed for a high revving engine - which the very long stroke 1098 is NOT - especially the normal engine. The later Spridget engines with the 2" mains are a bit stronger - but still not as keen to rev as the 1275.
This one was built by Morspeed on a 970 S block and crank I sold him![frame][/frame][frame][/frame][frame][/frame]

It seemingly does very well in it's class - in Sri Lanka!