[EcoMCA]

Originally Posted by freebeard

My thought is you left out the most important constraining variable: Year, make and model.

Via duckduckgo.com/?q=652cc+air+cooled+rear+engine+-motorcycle the likely candidate is the Fiat Panda.

According to www.classicandsportscar.com/features/square-space-fiat-panda-40:


23hp sounds like not too much.

Year/make/model is somewhat not applicable in this case as it is a v low volume kit car hence the option to change most things.
It's not currently on the road and hasn't been for a few years so it's somewhat a reasonable option to approach from either viewpoint for engine choice.


But current drivetrain is from an air cooled fiat 126 (presumed 1978-86)

They were originally speed limited to around 65mph @ ~4800, max bhp @4500
Wheels are only 12"

The 3cylinder is an EJ-VE daihatsu unit and is sat in a complete donor vehicle hence is an option with all parts available.
6k rpm would give a top speed north of 80mph with power being made up there on the EJ motor anyway would give the benefit of something in hand for safety in all gears.
Donor config is FE FWD AT
Parts other than the engine will likely be donated to update the project where possible.

A relatively low cost 'recycling' project using mostly parts already 'in stock' for a 2 person commuter with FE, some reliability and a bit of future proofing as well as not ruining the handling with a reasonable chance to would be a good set of goals.

Power is not a goal here and definitely would require a new transmission from the offset.
I'd even be willing to potentially detune the 3 cylinder in the future as anything north of 35 should be adequate.

A diesel/diesel hybrid would be a great end solution or possibly full electric and was a consideration;
But this doesn't fit in entirely with the low cost recycling project as well as using the above doner or keeping the current drivetrain would.
It may be a future option.