Well Ive spent hours searching for the twin cylinder A series
someone chopped up so someone pls help me with the link?

Ive been seriously thinking of a super economy engine since
for quite sometime now and would like to do an a12 bored to 76mm
for a 630cc turbo twin cylinder engine.

then I thought of another engine that would be interesting an SD25
diesel with small turbo chopped in halve would make a 1145cc twin
and probably around 80hp with the torque of a 2litre.
However the pump is the issue and would need careful machining to
turn it into a dual unit or maybe a perkins unit could be used?
edit: oiling could be an issue also with pickup at rear section
but the LD20 ohc diesel is better suited for a 1ltr twin.

I was looking at my friends motor bike the other day. It is a V twin @ 1400cc, 6spd box, shaft drive. It develops more HP and Torque than a stock A12. So why not just drop in a Vulcan and off we go.

It is the infamous A6 Engine

Pete you are mad Nah seriously Im in the same boat
looked into a v4 halve chevy 3.2 motor.
The Kawa v-twin is so expensive the v4 sesco type motor is cheaper
in the end.

But the exercise now is an easy to make nissan twinnie in either
lpg/turbo or diesel.

DD thanxs forgot about the a6 naming quite logical really

Have you considered the subaru sherpa engine, its essentially half a boxer 4. My wife used to drive around in one, years ago, and i remember that we drove it to brisbane and back to sydney on around $85. From memory it was around 550cc and was a crosflow OHC engine. It just kept on going.

edit: I looked it up on the web, advertised engine specs are as follows.

Subaru Sherpa / 700
1982 - 1989
Engine: Water-cooled 2-cylinder
Capacity: 665 cc
Power: 27 kW / 54 Nm
Transmission: 4 spd. man
Top Speed: 125 km/h

I used to have a sherpa but the truth is it was no more economical as an a10.
Id like to keep it nissan if possible at worst a 700cc A6 with boost
the gearbox mount could be made using the side engine mounts for extra
support. A kind of C plate to cover hold the rear main seal and bolt up to the
engine mounts, exhaust side of the head and inlet side.

I think now on looking at several Diesel engines and the limited info
Ive done a backflip and decided the L20B engine with a Ka24e head would be the go.
Everything is in the right place with oil pick-up, dizzie and mount on the front
section of the block.

The Ka24e head has two large inlet valves at 34mm and one fat 40mm exhaust

Why not just convert one of the ma10 micra engines to rwd, aren't they only a 1000 and turbo from factory?
Or is that too easy? :)

or even better the ma09ert. From the nissan march superturbo............... That name makes me laugh everytime!

whats the fun in that?

Nah seriously a simple A6 on boost would do for 70hp and good economy
654cc
76mm bore
70mm stroke
The only issue is finding 126mm rods to allow for better rod/stroke ratio
of 1.785 or so to smoothen the nervous shaker
Does anyone know of any 125mm rods or there abouts? I know toyota 4age rods
are 122mm but .5mm wont cut it.

but what about torque, cant see a a6 doing much even boosted, i feel that a better built a10 with balancing would do a lot better in bossted form and with the increased torque would be better for economy due to not having to rev the crap out of it up any sort of incline... i know 400cc but still almost double the capacity and on lpg, would be a miser