I should have mentioned that there are OX5 engines for sale also. A Cruisair with an OX5 on the front???? Velly intelesting. On a more serious note, one of the Franklins might be a horizontal helicopter engine. I only say that because it has a timing access on the accessory case. I have never seen that on a 150/165, but I have seen that on a 235 HP horizontal copter engine. ___Grant.