OHV Sectional View

[MRD]

Dear All
Recently I came across an interesting picture in an old book.
The book is “The boys book of the Motorcycle” printed in 1928
The picture is a sectional view of a 596cc overhead valve motor.
Are there any knowledgeable people who can tell me which model it came from?
Regards    MRD

[Alan Cun]

Sure can Model OB and OC touring models. The OB having the same type wedge in pulley brakes as per CW also having a gearchange outside the tank. Now the OC has the band brakes as per EW and models up to about 35 other models. The gearshift on the OC was sloted within the tank as per EW. The motor was produced in both 600cc and 350cc versions. As Ian and Graeme will agree a very sporty and great machine for the road. If You click onto the the section View idetification by model good pics there. regards Al

[MRD]

If my memory serves me correct. The late Brin Williams (long serving member of LDMCC) owned an OB in which he completed the Isle of Man TT circuit only using TOP gear. Having ridden the circuit on a Mk3 myself, this mush have been quite a trial in itself.
And it shows how much torque this type of motor must have.
Regards   MRD

[Ian]

Main difference between the OB and OC was that the OC motor introduced a mechanical oil pump in the timing cover - can't see on this whether it is there. Also beefed up crank, etc.

As Alan says they are a wonderful machine - and top gear is all that is required !! When I was running mine in and having problems with timing slipping it still went up Mt Keira Rd in top gear (for those who know it - very steep and windy) with no toruble. Thank goodness as the gearbox is a real pig getting revs right for the 3rd to 2nd change !