Like Ian Lougher at Chapman Racing, Michael Dunlop is another rider who has the choice of two Agostini-era 500cc MV triples for the Senior Classic TT.

In Dunlop’s case, he has to decide between a Black Eagle Racing machine of the kind that won the race last year, and a new short-stroke version designed by the team’s young engineer Mitchell Kay. Dunlop has now done four laps - the equivalent of tomorrow’s 151-mile race - on the short-stroke engine, and Mitchell says:

“We can’t ask for better from it. It’s all new out of the crate, so to speak, and had only been run for five minutes on the dyno before we came here. It’s a long lap here if you want to make adjustments, which means you can’t get at the bike for 30 minutes. With the older engine we’ve got all the settings, but we have to learn them with the new engine.”

The Kay family, who run the Black Eagle team, had the same motivation in creating a short-stroke engine as factory teams have - higher revs, more power. Mitchell’s justification for building an engine that MV itself never made in the classic era is that it’s what the factory would have done if it had remained in racing.

Dunlop, Mitchell and Black Eagle director Mark Kay will sit down tonight to decide whether he should race the older engine or the new short-stroke. The decision might be complicated if the forecast rain curtails 500cc practising. That will mean that Dunlop will have ridden only the newer motor, and will have to rely on his memory of the older bike as a comparison.

It’s only classic racing, but to the participants out here in the Isle of Man, the drama and tension is as high as at any MotoGP round.