"What is this?" you might ask... These images are of George Morse's custom Prop. Speed Reduction Unit (PSRU). I have noticed there are 3 basic types in the market for experimental aircraft engines. The 3 types are Belted, Chain-drive, and Geared. The more popular ones, primarily due to co$t, is the Belted variety. There is a "SeaBee" that uses an LS-1 automotive conversion engine which uses a chain-drive PSRU. This Morse PSRU is the only one I know of in the market that is of the "geared" variety (of note, Teldyne Continental & Lycoming use geared reduction units for their FAA certified engines, as well as the Allison & RR Merlin V-12s ). George designed this PSRU around Chevy Muncie 4-speed manual transmission gears & bearings. The reduction works out to 1.67:1 gear ratio allowing the LS-1 to run at 4800PRM while the prop turns 2600RPM (max speed for the 3 bladed McCauley prop). Note also the small gear is splined and fits onto a splined snout of a custom forged stroker crank used in the LS-1 conversion. This redux unit is also used as a timing chain cover but the oil pump must be removed and a external high-output oil pump is used in it's place.

Nice Job George!