Taurus OT Stunt - engine choice

I have been looking at the plans for Taurus, a UK old time stunter for quite a while and have been put off by the expensive engine choice on the plan a rear rotor McCoy .60.

The plane is a 67" span plane that allegedly flew on 100' lines and could glide for two full laps after the engine cut.

What would be a suitable and affordable modern replacement for the McCoy?

Cheers

I'm pretty certain that you are in England, so your OT/Vintage Stunt rules would be pretty much unknown to us. You didn't say if the McCoy used spark or glow, or if you are going to fly contests with it. However, a Super Tigre ST .60 came immediately to mind, but look at Stalkers, Double Stars, Merco .61, MDS .58, and the bigger PAW Diesels. How about a 4-cycle? I would look for a good used Merco .61. The .49 is just as heavy (same case). Also, the first Fox Eagle .60 was about 14 oz, close to the weight of the ST .60. Many baffled piston RC .60's should be available used at very reasonable prices, and they would work, and most of them are about the same weight as the McCoy and at least as powerful. If they won't run a 4-2-4 run, just go to a flatter pitch prop to
control the speed and add blade area to keep the rpm down. Hope this helps, Steve