Thanks for the kind comments, but that racing part is not true. In fact, the vast majority of the Jett engines are designed for sport, scale, and aerobatics applications. The only two engines for racing these days are the QM40 and QJ-40.

Dub does configure some of the engines for speed applications. You will read a great deal about whiplash and diamond dust speed planes. The key here is that all of the engines are build and configured to order, based on the application for which they are intended.

Over the past couple of years, Dub has developed the big-block BSE engines into amazing powerplants.

Although Dub does make an awesome "90" engine, the SJ-90L and BSE-90L, the Jett BSE-100 and BSE-120 were designed from the ground-up for pattern/3D/scale applications. They turn larger props at lower rpm. All 3 engine are "60" size cases, and they match the mounting dimensions of the OS91FX. Any of the Jett engines are available in either side or rear exhaust configuration. The BSE-120 FIRE version, engine only and spinner nut, weighs about 21oz.

The engines typically are set up to turn in the 9000-11000 rpm range, but when set with a longer pipe, they gladly turn down in the 8500-9500 range.

The engines are not pumped, as with the OS91 or ST90.

As a pattern flyer from some time ago (1980s, early 90s), I sure wish I had one of these back when I was flying I had a sweet flying EU-1A that would have really enjoyed having a 90L in the nose.

I hope this is useful, and provides another "90" size option to consider. Any questions, feel free to email or PM.
Bob