RE: MVVS 1.20 with long pipe
AJF,
I have not seen such an engine yet, nor have I seen its 1.44 sibling.
They are said to be a bit problematic to set up.
Maybe Pé Reivers could add more info on it.
It does have two piston+cylinder sets, from the very successful #3090 GFS/R 10.0 cc (.61 cid) engine.
Induction balance and reliability are not one of its fortés, however.