A ‘Cornet’ engine showing the Y shape conrod and 2 pistons also showing the easy access to the crankshaft.


1952Express with Kuchensplit single motor 2
A rare Express Radex with a slit/single motor designed in 1938 by Richard Kuchen and made by Baker and Polling designed by Kuchen Hence the name BP-K the motor was not reliable rear piston suffered from  seizing and was drop after a year by Express.



1952Express with Kuchensplit single motor

Zundapp split single
A Richard Kuchen split/single design for Zundapp in 1936 a very sleek design but was nether put into production! but the engine became the BP-K design for the above Express.


Triumph ?TWN cornet engine
inside the Cornet engine with the one Y shape conrod.The image top lefthand corner is of a prototype 250cc engine which double up 2 x 125 engines looks good but power output was similiar to the standar 250 BDG engine,so it was only a prototype.
This is a PUCH 175 SVS engine showing the configuration of the Puch split single system
Puch and 'Cornet
Puch ‘s split/single system (showing the 250 SGS crank) and bottom picture showing the’Cornet, barrel and head.
A unique racing car from the 30’s a Monaco-Trossi 8 barrels= 16 cylinders =16 pistons plus 2 superchargers = 260 BHP and a two/stroke! what must it sound like??also note the spark plugs protrude beyond the engine cowling.
Monaco Trossi
early version with no engine cowling.
Nice drawing showing the 8 barrels = 16 cylinders not 32 as said above! also it had 2 superchargers power out put was 260 BHP but the balance ratio was 75% front and 25% rear resulting in hugh understeer!!
Commer lorry
The British made Commer lorry had a 3 cylinder split/single engine also it was two/stroke diesel!!

I have taken a look at the Commer engine given the name Rootes TS3 yes it has 3 cylinders yes it has 6 pistons and yes it has 3 combustion chambers so does it qualify as a split single!! as Doctor Spock would say yes’ it’s a split single, but not as we would know it’!!!


The Italian make ISO made a split/single in the fifties called the Isomoto(very similar in design to Puch 125SV) they also made a Isetta  bubblecar useing a 246cc split/single engine .later Iso went on to make high powered V8 engine luxury sports cars in the sixties.
iso 125 split single
Often confused with the Puch engine!! this is the snit view of the Iso 125 engine (motorcycle above) the puch has a primary chain! not a gear drive to the clutch.
A Puch crankshaft from a 1942 125T A Y shaped conrod but in a fore and aft configuration.also note the rear ie the one to the right small-end has a slight rectangle shape,so the piston can slide back and forth!!!