Home Up Article Conversion Adaptation R/R Gear Engine Delivery


Ruston & Hornsby 2YC Diesel Engine - Marine Conversion.

(Click on thumbnails to view larger and higher resolution images.)


Engine stripped back to basic parts, masked up and given several coats of red oxide and zinc based primers. The zinc based primer was used only on aluminium parts but in hindsight it would have been better to use it on all the engine as experience has shown that it has much better adhesion properties on all types of metals than the red oxide based primer used.

The original mountings were discarded (only three out of four were with the engine when purchased and all three had been repaired several times). New mountings were fabricated from 10mm mild steel plate incorporating a more substantial 'shelf' for the base of the crankcase to sit on. An inadequate shelf and the cast iron construction of the original mountings probably were the cause of their repeated failure.


Most of the conversion work completed (99%). and painted. Not the correct colour for a Ruston & Hornsby engine, but a colour that appeals to me and suits the application. I used a synthetic enamel paint that was applied either by brush or sprayed (after thinning appropriately). The paint is standing up to the task very well, even on very hot parts including the cylinder head.

Note the large pulley to drive the alternator at the correct ratio, modified vee belt drive to the water pump and the additional copper and brass piping to cool the engine oil.

There are several methods of providing water cooling to the engine. I prefer the keel cooled method used on the majority of narrow boats where a thin tank is welded to the inside of the swim. Water is circulated directly through this tank to the engine using the normal centrifugal pump mounted on the engine. This type of cooling system means that you only need one water pump and not two as required by other systems and by using antifreeze it is not necessary to drain the system down when not in use during the winter months. The engine in it's stationary role had a suitable pump already mounted with a thermostat fitted. The 900 outlet was modified to allow it to be turned to point forward to connect to a bulkhead mounted header tank. The vee belt drive was by an adjustable length belt but this was replaced by a normal fixed length vee belt. To provide a means to tension the belt, an adjustable pulley from a Ford Pinto engine cam belt tensioner was mounted to work on the top face of the vee belt half way between the pump and crankshaft pulleys on the slack side. This is probably all better understood by studying the photograph.

Most marine engines provide some means to cool the engine oil. The most notable exception being the reintroduced Gardner 2LW marine engine. I was somewhat surprised to find this out and was thrown into confusion as to whether the Ruston required an oil cooler or not. In the end, I decided on a compromise, the use of an oilstat. This is a device used mainly on cars to stop over cooling the engine oil when used in winter or other similar circumstances. The oilstat used is set to operate at 780C. If necessary, the temperature element can be changed to 980C or removed altogether!


Rear views showing the instrument panel, exposed flywheel, brass oil pump for empting the sump and made up air filter.

The type and level of engine instrumentation is a personal thing. I prefer to have enough data to be able to diagnose potential problems before serious damage or failure occurs. On a traditional narrow boat engine, brass gauges mounted at point of measurement would be appropriate, but give no early warning of trouble, being remote from the steerer. I decided to use conventional gauges, engine mounted in a housing, with visual and audible alarms, both at the engine and steering positions.

The new mountings were designed for the engine to sit on substantial bearers and thus the sump would be inaccessible for changing engine oil. This is a normal problem for most engine installations in boats and is easily overcome by the use of a hand operated sump pump. One of the 'delights' of a traditional engine room is the amount of polished brass and copper adorning the engine. The pump is made of brass, but a lot of installations are spoiled by using plastic or some other unsuitable material to mount it. After much searching, I found that a brass clamp for making a solder less tee connection to a straight 28mm water pipe would be ideal. A few modifications and the perfect mounting clamp was produced. A bracket from the fuel filter provided the suitable location to attach the pump.

The engine was missing it's air filter assembly when I acquired it. Normally, an oil bath type is used. I had toyed with the idea of finding an original part but I soon decided to fabricate a suitable unit. The design was based on using a foam element from a Peugeot 205 GRD diesel car engine. Two circular end plates were made and a wire gauze tube fabricated to fit inside the end plates and enclose the foam element. Before use, the foam element is soaked in thin engine oil and allowed to drain before being assembled.


After many months of searching I finally acquired a flywheel housing, thanks to the Internet. The housing was fitted and solved the problem of attaching the gearbox. Various views prior to fitting flywheel housing and attaching reverse/reduction gear, all described in the following pages.

Page last updated 20 December 2005

Michael Clarke - 2009