These are some engines I've converted or otherwise modified. I've been working on
some diesel conversions of radio control (RC) model four stroke glow engines. The engines start easily and run well. Power is
on par with the original glow version or better. The engines run
quietly and are tolerant of needle settings. Fuel consumption is
typical of diesels, roughly half that of glow. Compression adjustment is accomplished via the glow
plug hole by an adjustable volume chamber.
The conversion process consists of increasing the compression ratio to what
is required by the fuel. To increase compression ratio I modify the head, crankcase, pushrods, pushrod covers, and intake manifold. I also
modify the carb slightly to improve fuel draw and throttle response. The "lanova cell"
is what we are calling the adjustable compression device is made to suit the engine size.
To date, the following engines have been successfully converted: OS FS-25(an OS
FS-20 stroked with an FS-26 crankshaft), OS FS-26S, OS FS-30S, OS FS-40(1981 version), OS FS-48S, OS FS-52S, Magnum XL52AR, and Thunder Tiger F-75S.
These engines are in progress and should make acceptable conversions: OS FS-40S, OS FS-70S, OS FS-91S.
O.S. FS-26 Surpass
The FS-26S is
probably the nicest running of all of them. It requires many modifications, however. The video was taken before
final tuning so it knocks a little. Click the image to the left to see the video. The clip is about 2.4Mb.
O.S. FS-40
This is
an old OS FS-40 conversion. It runs well on Eric Clutton's bearing mix
fuel.
Graupner Nylon Props
10x6 9700RPM
11x7 8200RPM
12x6 8200RPM
O.S. FS-48 Surpass
OS FS-48S Surpass makes
plenty of power. I have the most flying time on this engine. I used a Grupaner 12x7 during the 2011 season and it ran very well. The airplane was faster and climbed better.
Graupner Super Nylon 12x6, 10200RPM
Enya 41-4CD
This is a designed for diesel four stroke from Enya. They are readily avilable through the Enya website.
Thunder Tiger F-75S
The TT F-75S diesel conversion turned out well. It's running a Graupner 12x7 Super Nylon prop in the
video at about 9000 RPM. The engine still needs a lot of time to break in as it is new. I did the conversion for an Australian mate who I'm sure will enjoy it. Fuel is typical
model diesel fuel containing castor oil, kerosene, ether, and DII. The knocking you hear is normal for my diesel conversions. It's alarmingly loud, but I found this is the result
of my test bench amplifying it. Properly warmed and tuned it doesn't make any of these sounds as can be seen toward the end of the clip.
