We have recently decided to add the RCV
line of engines to our products list.
These engines are unique and offer advantages for the
modeler/flyer that are not available with other types.
Some of these advantages include:
made engines manufactured in the United Kingdom.
slim line shape that allows for close or minimum cowling and
SP series allows a larger scale propeller to be used, as the prop
speed is lower due to a 2:1 reduction.
CD series features a lower head height allowing installations in a
tighter space than most four strokes.
2-year factory warrantee.
We are publishing a list of the most
frequently asked questions, furnished by RCV limited, to help
acquaint you with these fine engines. You can contact us or the
factory for any further or specific questions on or for more
information concerning these products.
the engines 2 or 4 cycle? They
are true 4 cycle engines.
fuels are recommended?
10% nitro/ 15% oil (inc.
between 3 and 6% castor oil). Specific recommendations include:
Morgan omega 10%, Byron Premium Sport 4 –cycle 10%,
Wildcat Premium 10%. The
engines are more fuel sensitive and it is essential to use the
fuels or mixes shown above and they highly recommend the use the
OS “F” type plugs.
they be used as pushers?
Yes! Make sure
you have adequate cooling, especially on the SP engines.
the engines be reversed?
No! They go
CCW and cannot be made to run clockwise with out extensive
there different angles for the exhaust pipes?
NO. Only the
standard ones furnished with each engines are being produced by
RCV but the pipe threads are standard and other ones can be fitted
to them. . RCV 60SP = M10 X 0.75.
RCV 58-CD, 90-SP and 1.20-SP are M11x 0.75.
next engine to be produced is the 96CD available in Jan. 2004.
do the gears hold up? They
are flame hardened and have been tested for 50 hours with no signs
How does the power of the 58 CD compare to other engines?
The factory says the engines are equivalent to other 4
cycles of the same displacement, or a 40 2 cycle.
Some field reports, however, indicate they have greater
torque and are stronger than the regular engines.
Is the 58 suitable for control line stunt flying?
The engine is currently being tested for this and RCV is
waiting for the needle valve and venture assembly to be developed
and tested. More soon
What is the fuel consumption of the 58 CD?
Tested by using 50 ml consumption comparisons at various
TIME (secs) ML/min
size propeller is recommended?
The 58 CD uses conventional sized propellers.
11x6, 12x6, for
break in. Operational
uses include the 10x9, 10x10, 11x7 and 11x8.
I run the engine inverted?
it is suggested to break the engine in while in the upright
I rotate the carburetor 180 degrees?
kind of engine mount is needed?
Although much shorter than the conventional engines, this
engi9ne is slight wider. Any mount that is strong enough including
a flexible one.
have oil leaking from the crankcase breather!
This is normal during the break in period. This should slow
and then stop as the engine is broken in. Break in time is 1 hour.
is leaking from the front bearing!
Some green grease may be seeping from the front bearing
during the break in period. This
too should slow and stop after the breaking period.
are the SP series engines equivalent to in power ratings?
Again the factory says they are equivalent to other 4
stroke engines of the same displacement. However, field test again
point out their greater torque and power.
is the fuel consumption of the SP series engines? Using average flying as the parameter:
60 Sp = or > 0.4 oz/min
90 SP = or > 0.55 Oz/ min
120 SP = or > 0.7 oz/min
is a typical noise level of the SP series? At about 22 feet the
following levels were recorded.
60 SP = 80 – 82 Db
90 SP = 80 – 86 DB
120 SP = 82 + DB
How does the engine sound?
The sound is different that the normal 4 strokes.
Most like it, some do not.
The difference is mainly in the gears.
It tends to give out a slight click due to gear lash each
drive direction reverses at TDC thus the noise. If your engine is
noisy after break in check the backlash.
Refer to Backlash in tips and hints.
it be better to have the cooling fins run the other direction?
This is one of the most asked questions we receive.
This engine is cnc machined and not cast.
On testing, we discovered the direction of the fins does
not cause any cooling problems.
happens if the engines get hot?
They are designed to run at reasonably high temperatures
due to good thermal characteristics, therefore, insufficient
cooling should not have any adverse effect.
If cooling was not sufficient, the worst that should happen
is the engine would loose power and if really hot, could perhaps,
melt a propeller. ____________Thermal
Characteristics: Clearance between the rotating cylinder and outer
jacket is very small < 0.1 mm. The heat is transferred across this gap by an oil film. On
larger versions of the RCV, oil cooling is accomplished by pumping
oil over the outside of the rotating cylinder.
Thermal distortion is very low, unlike a convention engine
there is no hot and cold side to the combustion chamber and no hot
exhaust valve to cause detonation.
tightly cowled, how do we cool it?
The cylinder jacket is designed to dissipate heat and the
airflow over the prop shaft assists in cooling. IF completely
enclosed, airflow should be assisted by baffles or deflection
ducting used to
increase the flow. The exit area should be 2 times the intake
area. Rough guidance is a minimum of 1 sq inch for intake and 2 sq
inches for exits.
size props are recommended? Being
geared, the prop is turning a ˝ the engine speed therefore larger
props are used. Pitches
of 10 to 14 and not less than 10.encluding break ins.
RCV60 SP= 16x12; RCV 90 SP = 18x12; RCV 120 SP = 20x12.
wood props be used? We
always recommend glass composite props, however, wood ones of good
quality can be used and have been in some testing.
It is important to use good quality, heavier wooden props
because generally wood ones are lighter and do not furnish the
flywheel effect. RPM will be lower with wood props.
spinners available for the engines?
can supply them if you can’t find them t your hobby shops.
they be prop started? We
only recommend the behind the prop method for safety reasons, but
you can start them by spinning the props.
Remember the props are larger and spinning at half the
speed of the engine so the 120 sizes is more difficult to start
using this method.
does the starter adaptor work?
Use a standard starter and insert the adaptor directly into
a socket located on the end of the crankshaft.
This turns the crank gear that turns a planetary gear
around the base.
I rotate the engine with the glow plug at other than the 12
o’clock position? Yes.
However, the fuel tank height might require an adjustment
reference the carburetor.
do we mount the engines?
Larger torque from the geared prop means
mounts should be substantial and beefy and the engine securely
mounted. The forward fuselage and firewall area must be strong
enough to handle this torque. The engines would normally be
radially mounted on the firewall. And we recommend using a
reinforcing metal plate. A
mounting plate is now furnished with the SP serried engines.
Rubber mounts are not recommended.
Tips and Hints
1 How can I prevent castor oil build up on
the exhaust? Application
of WD-40 on a rag after you stop running can clean off the oil.
do you adjust the carburetor?
Main needle: This
is done while at full power.
Len out the engine until peak rpm and then enrich a little.
This should nearly duplicate the in fight leaning that
occurs. Raise the nose of the model to vertical and check for
proper running. Lean= screwing in; richer = out. Idle adjustment: If
operation at low or mid throttle is not proper, this usually means
the idle adjustment is incorrect
Too Lean: Tendency
not to start at low throttle settings.
Once started, it usually runs clean at mid throttle but
dies at low throttle or rapid advancing of the throttle and with
little or no increase in speed when the glow plug is energized.
Too rich: Good
starting but runs rough at mid throttle settings pops and sputters
at idle. Runs better with the glow plug energized and will increase in
Good starting and clean running at all throttle settings.
Idle sounds slightly rich and may pop a little. Idle speed
increases slightly when the glow plug is energized and when
throttle is opened rapidly the engine does not stall.
gear clearance: Measure
the free play at the prop. tip by moving the prop in both
directions with out moving the crankshaft, easiest to do with a
hot engine. The free play with a 16-inch prop should be around 1
to 2 mm. If significantly more and the noise is objectionable,
call RCV and RCV will fine-tune the engine.
troubles: When properly set up, RCV engines are very easy to
start. Most troubles
A weak starter
Starter going in the wrong direction. Very common Prop
should go CC.
Insufficient battery power for starting and the glow plug OS F
plugs draw about 3 amps
Start: Make sure the
above are ok then:
Open the main needle valve several turns, too rich is
ok but too lean and it won’t start.
Fully open the throttle. Place finger over the intake
and choke the engine until very wet. Fuel may drip from the
exhaust, this is ok.
Close throttle to 1 /3rd., energizer the
Engine should run needles might need further adjustment for
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