Please note:
1. Your engine will be covered with a light coating of oil used to protect it during transit.
2. The RCV engine will feel different from conventional engines. The RCV design is a geared en-
gine and when cold it will possible to feel the gear teeth meshing as the engine is turned over.
3.
Remove plastic plug from crankcase breather (this is to prevent oil seepage during transit)
4.
The rotary cylinder valve may also appear slightly stiff and oil seepage may occur from around
the starter bearing.
5. As part of quality control some engines are tested prior to use, therefore mounting marks may
be seen on your new engine
GLOW PLUG
•
As the glow plug on the RCV is ported, selection is more critical than on conventional engines,
and fitting a non-recommended plug may produce a significant drop in performance when the
glow battery is disconnected.
It is strongly recommended that the OS type F plug is fitted.
•
DO NOT USE AN IDLE BAR PLUG. This may protrude into the rotary valve, and lock the engine
up, damaging the surface of the rotary valve.
FUEL
•
For maximum efficiency we recommend that
10% Nitro
content fuel is used and the RCV
compression ratio is set up to use 10% Nitro. Fuel with too low a Nitro content will produce a
significant drop in RPM when the glow battery is disconnected as well as an unreliable idle. Do
not use fuel with more than 15% Nitro as this can result in engine failure.
•
Fuels must have an oil content of around 15%,
between 3 & 6%
of which
should be Castor Oil
,
but not more than 6% as this can cause rough running. The reason we recommend a blend of
castor and synthetic is because castor promotes cooling, whilst synthetic protects the engine
components from wear
•
Model Technics Duraglo fuel with a mixture of 6% Castor Oil, 9% EDL (Synthetic Oil), 10%
Nitromethane, 75% Methanol, has been used for the bulk of the flying and bench testing to date
and found to give good results. Other suitable fuels include: Wildcat Premium 10%, Morgan
Omega 10%, 10% Byron Sports 'Standard or 4-cycle'
PROPELLERS
•
Due to the 2:1 gearing the propellers are turning at half the RPM you would normally expect,
therefore propellers used are both larger in diameter than would normally be used with a conven-
tional engine but also
TWICE THE PITCH
is needed to maintain a reasonable airspeed and to
ensure the engine does not over-rev. A list of propeller sizes can be seen in
SECTION 5
.
•
RCV do not recommend most wooden propellers, as they can cause increased vibration and are
less efficient.
SECTION 3 GLOWPLUG, FUEL & PROP SELECTION
Prior to use, please ensure your exhaust is tightened
RECOMMENDED PROCEDURE FOR TIGHTENING YOUR EXHAUST PIPE
Use a 14 mm spanner which has a ring spanner at one end and a conventional open spanner at the
other. Use the open-ended spanner to remove the muffler. Slide the ring spanner along the exhaust
pipe and locate it over the exhaust pipe lock nut. Turn the exhaust pipe to the desired angle and
tighten the lock nut firmly. Slide ring spanner off down pipe. Replace silencer and tighten locking nut
with open-ended spanner. Carry out the above operation with the engine warm so that the exhaust is
tightened when the threads are expanded and use the maximum amount of thread.
If you need a different angled exhaust pipe, you can use one that is suitable for other 4-stroke engines.
RCV have standard exhaust thread sizes – 90SP = M11 x 0.75
We take every care to ensure this engine reaches you in perfect condition. If this is not the case,
please advise us at the earliest opportunity. Your package should contain the following items:
SECTION 2 RECEIVING YOUR ENGINE
•
RCV90-SP engine
•
Exhaust pipe and muffler
•
Spare starter cap screw
•
Mounting Backplate & Screws
•
Warranty Form (
please complete and return immediately
)
Issue 2 01/06/2004 © RCV Engines Ltd
Page 2
This engine is subject to Global Patents and Design Copyrights
Reassembly of the engine is a simple operation. The main difficulty is in ensuring that the gears are
engaged in the correct position so that the engine is timed correctly. ABOVE ALL THE TIMING MUST
BE CHECKED CAREFULLY BEFORE BOLTING THE CARB AND EXHAUST BACK ONTO THE
ENGINE.
The engine is timed at top dead centre between the inlet and exhaust stroke. At this point in the cycle
the cylinder port is exactly halfway between the exhaust and inlet. If the engine is assembled so that
the piston is at top dead centre when the cylinder port is halfway between the exhaust and inlet, then it
is timed correctly.
Insert a 5 mm Allen key in the starter drive Allen screw. Turn the crank to top dead centre. Carefully
note the angle the Allen key assumes when at top dead centre, and as an additional check mark the
top of the starter drive Allen screw to mark the position of top dead centre.
Take the cylinder jacket and rotate the cylinder until the cylinder port is equally visible in the exhaust
and inlet ports. About 1/8 of the port should be visible in each. This will require a bright light shining
directly down the inlet or exhaust port to be sure of the position of the port. Now insert two cocktail
sticks (or similar suitable wooden or plastic implements) into the exposed segments of the port to lock
the cylinder in position. Finally, holding both components in these positions, bring them together
carefully with the four boltholes lined up.
There are four possible rotational positions where the boltholes will line up. The one that is most con-
venient for the particular installation can be selected. As the cases are finally brought together the
gears should mesh with no movement of either component. Now insert and tighten the four bolts and
remove the cocktail sticks to free the cylinder. Do not attempt to rotate the engine until the bolts are
done up at least finger tight as the compression will force the two halves apart and the gears will jump
out of mesh. Rotate the engine one turn, until it is again at top dead centre between inlet and exhaust.
Carefully check that the cylinder port is equally visible in the exhaust and inlet ports.
If it is not, dismantle and carry out this assembly procedure again.
When reassembling the exhaust, it may be necessary to use a small amount of silicon sealant to limit
any leakage that might occur.
REASSEMBLING AND TIMING THE RCV
When timing ring is set correctly,
daylight can be seen through
inlet/exhaust ports as shown.
Issue 2 01/06/2004 © RCV Engines Ltd
Page 7
This engine is subject to Global Patents and Design copyrights
