It was Bob Chantland's engine that was used for reference. The Ex had bigger valves, and a better flow setup on top. Cam timing is modern, as we had no figures for the Ex anyway. Paul Brodie has put one of the Ex OHC engines in a modern lightweight roadrace frame he has built using chrome moly, carbon fiber, etc. Although that engine has electronic ignition and a huge Amal carb, it is otherwise standard 1919 technology, and it is now tuned to give out 75 BHP at the rear wheel- pretty impressive! Sorry I don't have a picture, but you can see it on Paul's website flashbackfabrications.com
The road racer has been running in "Battle of the Twins" racing in the northwest, and shows good promise. Quite a craftsman is Paul.
Both the Cyclone and OHC Ex used four valves only.
Scott, My wife and I are interested in hosting a road run from the St. George Hotel in Volcano. Do you think you have any info about those old runs? A route map would be really helpful. That hotel, town and general area are favorite places for us. thanks! Pete