Classic Water-Cooled Model Power Boat Engines.
Back in the 1960's when I made my first Classic Model Power Boat kit (an Aerokits Swordsman) almost everyone that ran model power boats chose to power them with a glow plug engine, occasionally a diesel engine, sometimes a petrol engine (in the bigger sized models), and only a few were powered by electric motors.
My Swordsman was powered by a 6.5cc OS40 Marine glow engine, and later by a 10cc Merco 61 Twin-Plug glow engine.
In those days, Classic Model Power Boats were probably at their most popular with lots of us building and running them in almost any stretch of water that could be found.
Places that I run my first model boat included various locations on the River Avon, the local Avon and Kennet canal, in the open sea off Torquay and Exmouth, several different village ponds (!) and the occasional visit to Victoria Park in Bath where the boating lake was filled with the sights and sounds of various r/c power boats hammering around making lots of noise and exhaust smoke!
These Classic Water-Cooled Model Engines have now been excluded from almost all waters where they were previously accepted, and most model boat clubs now actually ban their use.
Electric motors are much cleaner and easier to use, and can easily produce more power too - but they lack the "soul" of these internal combustion engines - and this is something that I really miss.
Part of the "operating procedure" included buying the correct grade of glow fuel (or diesel fuel) with the appropriate amount nitro content, making sure that your battery was charged enough to give a good bright glow when connected to the glow plug, remembering to pack the leather bootlace to start the engine with (electric starters came much later) and of course making sure that your radio equipment was working with fresh batteries too.
The procedure needed to bring the motor to life became a classic "starting ceremony" that often intrigued the casual onlooker as the owner/operator enthusiastically gripped the model by whatever means was preferred (I used my knees) to stop it jumping upwards as the leather starting lace was rocked backwards and forwards until the motor spluttered into life - when the bootlace was rapidly withdrawn in a flourish leaving the motor running (hopefully in the right direction!) and ready for action.
This was followed fairly quickly by the need to get the boat into the water before it overheated, when any final needle valve adjustment could be made (when the boat was in the water) before opening the throttle and seeing the model take-off and run until the fuel run out.
Judging the running time available (the amount of fuel that was left after starting it) became quite an art - especially when running in the fast flowing river waters as a model with a "dead" engine could be swept away causing all kinds of "interesting" recovery problems!
Anyone that had a small inflatable dingy became an instant friend and companion who was able to paddle after the stricken model and haul it onboard before paddling against the river flow to return it safely - often at a point some way further down-stream when the current was too strong to paddle against!
After the model was run (and recovered) the model needed to have a good clean to wipe away any spilled fuel and to remove any exhaust "goo" - before removing the glow plug to turn the motor over and placing a few drops of oil into the bore and then turning the motor over to give a good coating of oil all around the inside of the engine.
This after-run oiling procedure prevented the caster oil in the fuel from gumming-up the engine and the nitro content of any fuel that remained in the engine from eating into the chrome/nickel coating of the bore and the engine bearings!
Diesel engine operators could sometimes be compared to "wizards" as they balanced the compression needed to start the engine with that needed for it to run cleanly - with the same need to adjust the carburettor once the boat was in the water.
Compared with running an electric motor, these water-cooled model engines were hard work that could also be dirty and time consuming too - BUT - I really enjoyed the whole event - every time I took my Classic Model Power Boat out for a run it became a real occasion that plugging-in the battery on my current model boats can never compare with!
This "blog" gives an opportunity for others like myself that really miss these nitro and diesel fuelled engines to reminisce and picture their Classic Model Power Boat Water-Cooled Glow and Diesel Engines.
Bob.
My Swordsman was powered by a 6.5cc OS40 Marine glow engine, and later by a 10cc Merco 61 Twin-Plug glow engine.
In those days, Classic Model Power Boats were probably at their most popular with lots of us building and running them in almost any stretch of water that could be found.
Places that I run my first model boat included various locations on the River Avon, the local Avon and Kennet canal, in the open sea off Torquay and Exmouth, several different village ponds (!) and the occasional visit to Victoria Park in Bath where the boating lake was filled with the sights and sounds of various r/c power boats hammering around making lots of noise and exhaust smoke!
These Classic Water-Cooled Model Engines have now been excluded from almost all waters where they were previously accepted, and most model boat clubs now actually ban their use.
Electric motors are much cleaner and easier to use, and can easily produce more power too - but they lack the "soul" of these internal combustion engines - and this is something that I really miss.
Part of the "operating procedure" included buying the correct grade of glow fuel (or diesel fuel) with the appropriate amount nitro content, making sure that your battery was charged enough to give a good bright glow when connected to the glow plug, remembering to pack the leather bootlace to start the engine with (electric starters came much later) and of course making sure that your radio equipment was working with fresh batteries too.
The procedure needed to bring the motor to life became a classic "starting ceremony" that often intrigued the casual onlooker as the owner/operator enthusiastically gripped the model by whatever means was preferred (I used my knees) to stop it jumping upwards as the leather starting lace was rocked backwards and forwards until the motor spluttered into life - when the bootlace was rapidly withdrawn in a flourish leaving the motor running (hopefully in the right direction!) and ready for action.
This was followed fairly quickly by the need to get the boat into the water before it overheated, when any final needle valve adjustment could be made (when the boat was in the water) before opening the throttle and seeing the model take-off and run until the fuel run out.
Judging the running time available (the amount of fuel that was left after starting it) became quite an art - especially when running in the fast flowing river waters as a model with a "dead" engine could be swept away causing all kinds of "interesting" recovery problems!
Anyone that had a small inflatable dingy became an instant friend and companion who was able to paddle after the stricken model and haul it onboard before paddling against the river flow to return it safely - often at a point some way further down-stream when the current was too strong to paddle against!
After the model was run (and recovered) the model needed to have a good clean to wipe away any spilled fuel and to remove any exhaust "goo" - before removing the glow plug to turn the motor over and placing a few drops of oil into the bore and then turning the motor over to give a good coating of oil all around the inside of the engine.
This after-run oiling procedure prevented the caster oil in the fuel from gumming-up the engine and the nitro content of any fuel that remained in the engine from eating into the chrome/nickel coating of the bore and the engine bearings!
Diesel engine operators could sometimes be compared to "wizards" as they balanced the compression needed to start the engine with that needed for it to run cleanly - with the same need to adjust the carburettor once the boat was in the water.
Compared with running an electric motor, these water-cooled model engines were hard work that could also be dirty and time consuming too - BUT - I really enjoyed the whole event - every time I took my Classic Model Power Boat out for a run it became a real occasion that plugging-in the battery on my current model boats can never compare with!
This "blog" gives an opportunity for others like myself that really miss these nitro and diesel fuelled engines to reminisce and picture their Classic Model Power Boat Water-Cooled Glow and Diesel Engines.
Bob.
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This racy looking engine came in one of the LesRo Fisherman boats that I acquired not so long ago, and like my Merco 61 pictured above, it was in a pretty poor condition as it was covered in baked-on fuel and was totally seized solid.
Getting this engine cleaned-up and free to turn-over was actually the first glow plug motor that I worked on and it was the one that started my interest in trying to add a few more of the engines that I either owned or remember driving back in the 1960's and 70's.
The engine has good compression and looks nice on the shelf in my office.
Bob.
The third motor to join my collection of Classic Model Power Boat Engines was this lovely little OS20 that was kindly given to me by Ed, shortly after I sent him some drawings for a Perkassa.
I have done nothing to this engine yet as I have been away a lot since it arrived, but it is free to turn-over and so is the first engine to join my small collection that was not seized solid or covered in a baked-on layer of castor oil.
Cleaning this engine up wont take very long at all, but first I would like to find a carburettor needle and possibly a metal carburettor operating arm (?) to make this lovely little motor complete.
If anyone has these carburettor parts - or even a complete carburettor of the right size to fit this motor, please let me know.
Bob.