© 2017 Rotec Aerosport 

  • Facebook - Black Circle
  • YouTube - Black Circle

Radial Engines

Technical FAQ

 
Center of Gravity

The centre of gravity (CG) for both the Rotec R2800 and Rotec R3600 is approximately:

  • From the front view, close to the centre of the engine.

  • From the side view, slightly forward from the centre plane of the cylinders.

Noise & Emissions

For maximum performance, the Rotec Radial uses an exhaust collector ring, absent of noise or emission control systems by default.

We have not tested the noise or emissions produced by the engine. If these factors are of concern, you can add mufflers or catalytic converters to the exhaust system.

 

Engine Mount 

We design and fabricate Rotec Radial engine mounts specifically for your airframe.

Save the time and hassle of doing it yourself. The fastest and often cheapest way to move your project forward is to have one of our experienced fabricators produce auxiliary components for you.

 

Just follow these three simple steps:

  1. Fill out the Engine Mount Dimension Form:

  2. Send your completed form to our technical department. An engineering drawing will be generated and then sent back to you for approval.*

  3. We schedule fabrication once your approval is received.†

* Deviations from the standard four mount point fixed position design is allowed although this will incur additional costs. This includes swing mounts, three or five mount points, or non-standard bracing. Free engine mount drawings are offered with the purchase of a new engine if customers wish to fabricate their own.

† While we have previously designed engine mounts for many aircraft, in order to ensure correct fitment customers must provide dimensional data and then approve the engineering drawing before fabrication commences. If the mount is purchased with an engine, it will generally be fabricated towards the end of the engine production batch, assuming payment has been received.

If you are designing and fabricating the engine mount yourself, click here to learn more about the factors you need to be aware of.  

Oil Tank

We design and fabricate Rotec Radial oil tanks, specifically to suit your airframe.

Save the time and hassle of doing it yourself. The fastest and often cheapest way to move your project forward is to have of our experienced fabricators produce auxiliary components for you.

 

Just follow these four simple steps:

  1. Contact us for pricing, if you haven’t already done so.*

  2. Fill out the Oil Tank Dimension Form:

  3. Send your completed form to our technical department. An engineering drawing will be generated and then sent back to you for approval.

  4. Once your approval is received, fabrication will be scheduled.

* Rotec do not supply oil tanks that allow inverted use. Deviations from the standard top mount and side mount designs incur additional costs. For customers who have purchased a new engine and wish to fabricate their own, an oil tank design is offered free of charge if requested.

† While we have designed oil tanks for many aircraft, each is different and in order to ensure correct fitment customers must provide dimensional data and then approve the engineering drawing before fabrication commences. If the mount is purchased with an engine it will generally be fabricated towards the end of the engine production batch, assuming payment has been received.

Engine Oil

Click here for an oil flow diagram and other information on engine oil. 

 

Engine Inversion

To enable inverted use of the Rotec Radial, the following is required.

Fuel Supply:

  • Rotec TBI Fuel System, which is fully aerobatic unlike the Bing Carburettor

  • Electric Fuel Booster Pump

  • Fuel tank with internal flop tube (not available from Rotec)

Oil Supply: 

  • Oil tank with internal flop tube (not available from Rotec)

Propeller – Mounting Bolts

To avoid confusion and waste, propeller bolts are not supplied with new engines. There is no standard propeller thickness and therefore no standard propeller bolt length.

Fuel Supply Propeller Bolts Required:

  • R2800 – 6 x Metric M8 x 1.25

  • R3600 – 6 x Imperial 3/8-24 UNF

  • Propeller bolt torque settings is to be recommended by the propeller manufacturer. Torque specifications are dependent on the propeller material and thickness. For more information on propellers bolt torque specifications, contact Culver Props or Whirl Wind Propellers.

Corrosion Resistance:

  • Propeller drive dowels (lugs) – case hardened

  • Propeller hub – electro-less nickel plated

Fuel Metering

Options available for fuel metering include:

  • The Rotec TBI Fuel System, which is highly recommended as it offers superior performance, in flight mixture control, is fully aerobatic and is less suitable to carburettor ice compared to other carburettors.

  • The Bing Carburettor is offered as standard. Carburettor heat is recommended on this device as it is more susceptible to carburettor icing than the Rotec TBI Fuel System.

We have not seen any attempts to convert the engine to electronic fuel injection at this time.

Fuels & Additives

Note: Only technical information released by Rotec Aerosport should be considered correct. Many third party opinions found on the internet are inaccurate.

  • Recommended Fuel:

The fuel of choice for the Rotec R2800 and R3600 is AVGAS. The compression ratio of the R2800 and R3600 is 8.5 : 1.

All engines built before late 2005 (“B” specification) should restrict fuel type to AVGAS until ignition timing is reduced to 22 degrees to meet later model engines.

All engines supplied beyond late 2005 (Classified as “C” specification or above), will function on Premium unleaded fuels (95 RON or higher). C spec engines have the ignition timing set to 22 degrees to avoid any uncontrolled detonation. When using Premium Unleaded fuels (95 RON or higher), usage should be interrupted from time to time with the one or more tanks of AVGAS. AVGAS can be added to any remaining unleaded fuel in the tank, as there is no need to flush the unleaded fuel out of the system.

When using premium unleaded, it is wise to install a knock sensor to detect instances of uncontrolled detonation along with a close examination of the spark plugs looking for carbon build up; including a regular valve and valve seat examination looking for burning.

  • Recommended fuel additive:

 

Rotec Aerosport have tested and recommend Flash Lubes Valve Saver. It has been found to be beneficial in reducing the harshness of unleaded fuels. The product was found to be compatible with Premium Unleaded, AVGAS and in any mixture of these fuels. When using Valve Saver, flushing out fuels when switching from one to the other is not required.

Apart from less carbon on the heads and pistons, and less wear on the valves and seats; Flash Lubes Valve Saver also cleans the engines fuel delivery system.

Please check the internet for availability of Flash Lubes Valve Saver. http://www.flashlube.com/

Note: Care should be taken to ensure that any additives used are compatible with AVGAS, Premium unleaded or in any mixture of the two.

Warning: Continued use of Premium Unleaded on pre “B” specification engines, without the use of additives, will cause piston rings to crack, as well as valves and valve seats wear more rapidly than expected.

All unmodified engines supplied prior to “B” specification (prior to late 2005), contact us on how to retard the engine timing to 22 degrees.

If you are unsure of your engine specification please contact us. Quote your engine serial number and date of purchase if possible.

Can't find what you are looking for?

Click here to visit our support forum, where you can browse/ post your queries.