The 140 HP, four-cylinder, water-cooled Vulcan V-4 marine engine has been installed on a Rotorway Scorpion helicopter.

From Appendix 9: Manufacturer of the Raptor 105 turbocharged, horizontal 4-cylinder, diesel (Jet-A1) model. (Note: This may not be the same Vulcan.)

"The Raptor 105 turbocharged"

-It has a large reduction gear that also serves as a coupling for accessories such as the starter.