RCV Engines

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:

Quality made engines manufactured in the United Kingdom.

A slim line shape that allows for close or minimum cowling and streamlining.

The SP series allows a larger scale propeller to be used, as the prop speed is lower due to a 2:1 reduction.

The CD series features a lower head height allowing installations in a tighter space than most four strokes.

A 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.

                                                    FAQ 

1.        Are the engines 2 or 4 cycle?  They are true 4 cycle engines.

2.        What 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.

3.        Can they be used as pushers?   Yes!  Make sure you have adequate cooling, especially on the SP engines.

4.        Can the engines be reversed?   No!  They go CCW and cannot be made to run clockwise with out extensive engineering modifications.

5.        Are 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.

6.        The next engine to be produced is the 96CD available in Jan. 2004.

7.        How do the gears hold up?   They are flame hardened and have been tested for 50 hours with no signs of ware

                                              FAQ   58 CD

1     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.

2     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 on this!

3.    What is the fuel consumption of the 58 CD?   Tested by using 50 ml consumption comparisons at various engine speeds.

RPM          TIME (secs) ML/min            OZ/ min

3000                 580                       5.17                  0.18

5000                 500                       6.00                  0.21

7000                      390                       7.69                  0.27

9000                 250                     12.00               0.42

4.   What 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.

5.   Can I run the engine inverted?   Yes!  However it is suggested to break the engine in while in the upright              position.

6.        Can I rotate the carburetor 180 degrees?  Yes! 

7.        What 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.

8.        I 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.

9.        Oil 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.

RCV SP Series

1.        What 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.

2.         

3.        What 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

4.        What 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

5.        .   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 revolution.   The 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.

6.        Would 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.

7.        What 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.

8.        IF 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.

9.        What 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.

10.     Can 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.

11.     Are spinners available for the engines?  Yes.  Tru-turn can supply them if you can’t find them t your hobby shops.

12.     Can 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. 

13.     How 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.

14.     Can 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.

15.     How do we mount the engines?   Larger torque from the geared prop means

 The 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.

2   How 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 speed.

Correct settings:  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.

3   Checking 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.

4   Starting troubles: When properly set up, RCV engines are very easy to start.  Most troubles are in

5   A.  A weak starter

6   B   Starter going in the wrong direction. Very common Prop should go CC.

7   C.  Improper fuel

8   D Insufficient battery power for starting and the glow plug OS F plugs draw about 3 amps

9   To 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 /3^rd., energizer the glow plug

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