A Photo & Discussion Forum for Wharram Design Enthusiasts

Diesel motor idea.

Why not use a Mercruiser style outdrive leg with a small diesel engine on deck?
The drive leg fitted to pod wil take care of propultion gearing, forward neutral and reverse, water pump and pickup for engine cooling, steering iff needed , trimming and return of exhaust and water. The engine housed in a small enclosure wil be connected with short driveshaft and u joints with slip provided in driveshaft for lifting. U joints wil allow for lifting of pod out of water ( no drive at that acute angle ) . The water and exhust intake and return hoses can easily be extended. The engine enclosure wil not allow any water in and outdrive on pod can happily be submerged if needed at times without any problems. Weight of engine carried on deck, no syphoning possible so no gooseneck/loopes etc needed. Small Japanese import car engine in 1 liter class ideal. Also already equiped with alternator for battery charging, ac pump ( ac in cabins!) and powerstearing pump for capstan or something els. Sterndrive units widely available for cheap here and normally includes engine and controlls with most of marinizing already on engine. Drive any size prop you like....
Only negative : you have to have leg in water iff you run engine for charging only( in neutral)
Thoughts ???

▶ Reply to This

Replies to This Discussion

Permalink Reply by Maxim Jurgens on March 1, 2016 at 2:26am

It's all possible , I guess but if you want to go that way yo might as well consider a ready made catamaran drive like Sonic Sillette. They come with or without a gear box ,such as you prefer.

Re the small 1 liter car engine : you still need to marinize it ( water cooled exhaust , impeller pump, heat exchanger etc .Problem with car engines is that they often have an enormous oil sump which is difficult to tuck in the confined space of an engine box and which usually also very susceptible to corrosion .

Also I'm not so sure about a "one liter "diesel engine" being adequate. On a T30 or smaller any diesel installation is way too heavy .With a T 38 or bigger a diesel is a consideration worth making .Our T 38's are driven by a single Kubota VE 1200 ( 1235 cc) which gives about 24-26 HP . In our case they drive a twin propeller hydraulic system. In flat water we get 6- 61/2 kts out of them at cruising (2400 ) rpm. So adequate but certainly not overpowered .