Posted Thursday, January 14, 2016 @ 07:02 PM
This is just a note to the general community that I have received approval for the installation of a Great Plains 2180 engine in the RF5 on an EASA Permit to Fly. The approval is under LAA Mod 13988 which is available for anyone who wishes to adopt this.
If anyone would like to pursue such an installation and would like to know more I can provide detailed information and any help. All the necessary stress calculations, mechanical and systems engineering have been done and cleared, which would save any follower of this path considerable time.
In summary the engine is a 2180cc Great Plains (VW Type 1 magnesium block) married with an original Limbach accessory case including flywheel, alternator, starter, magneto and carburettor. The induction and exhaust systems are unchanged and there are no changes to the engine supports, baffles or cowlings. The engine has electronic secondary ignition firing a set of lower plugs in each cylinder. Except for the propeller and spinner there are no external visible changes. In the cockpit there is now a digital tacho, an extra ignition switch and dual gauges replace the old oil temp and pressure.
The current approval uses a Hercules 58Ē x 38Ē propeller, but that could be changed.
My prime reason for changing the engine was not to increase performance but because some parts of my old 1971 L1700 were really coming to the end of their lives and repair didnít seem economic. However the opportunity presented itself to improve the somewhat poor take-off and climb performance so fitting another 1700 didnít make sense.
A rather extortionate quote from Limbach for an L2000 made me look for alternatives. Since I didnít want to change the engine supports and I didnít need a certificated engine I went down the route of building one. Otherwise I would probably have chosen a Sauer.
The project started in May 2014 by asking the LAA whether they might approve such a fit. After an agreement in principle this was followed by a detailed engineering proposal in October 2014, when the engine was also ordered. Building started in December 2015, first flight in August 2015 and following the final test flight in October 2015 a Permit was issued by the CAA in December 2015. There were a lot of delays due to paperwork plus my inspector suffered a grave illness and I injured myself falling off in a cycle race.
I am sure someone else can repeat this in half the time.
Performance isnít totally quantified yet as the engine still needs some adjusting, but take-off and climb are improved. The cruise seems comfortable at 3000 rpm and 110 mph TAS. Fuel consumption is no different.
I estimate the performance isnít much different to an L2000 but it was achieved at less than half the cost. The GP2180 is also less stressed running at a lower compression ratio, has dual ignition and the parts are far more easily obtainable and cheaper than the Limbach.
Hopefully it will power my RF5 for another 45 years.
There are some pictures here:
RF5 #5107 G-BEVO