Just wondering if anyone has experience with running the RW 162 engine above the 4250 for extended time,

I am looking for what would happen IF the engine was run at say 5000rpm, continuously would it make more power, would it explode, would it last?

In this idea I am not using the FADEC system I am using the TBI system which I have proven at the regular 4250 rpm, and my outside scoop cooling system.

But just thinking outside the box.... what if a gearbox was designed with an output at 520rpm but the input around the 5000 would the engine be OK?

i think Joe Huff would be the one to talk to about this.
my main concern would be the valve train being designed for an additional 18% RPM plus margin. this isnt an unreasonable RPM for the sake of the engine design looking at an automotive point of view. our displacement and rotating mass weight is light enough this could support the acceleration forces at the piston. i Know Joe addresses his piston weight/increase in acceleration forces in his stroked out 172's by using lighter and shorter piston skirts. maybe a similar piston used in an original 162F would render safer operation at higher RPM.

another major factor to consider is we are a single cam Push Rod engine so there is that in the engine design that goes against High RPM operation, and we are not talking about an automotive momentary rev up to 7000 like they are designed to do, we operate at a sustained continuous 4250 which is a high rpm for cruise in any car. 5000 is asking for trouble even if you used a subaru engine for hours on hours. i actually like the idea of the 3900 RPM engines over the 4250 engines because of decreased cyclic loads over time reducing wear but would take some modification to maintain the same power.

hope i gave some food for thought.

Thankyou @Lyle Swallows yes a lot of food for thought, engines are not my speciality.

I don't like the idea, but this is definitely a Joe Huff question. I'll see if I can get him to respond here. Putting all wear/tear theories aside, a big difference is the lack of torque. In our helicopters if you get behind to power curve there can be situations where there is not enough torque to bring the rpm back up with throttle alone. At sea level, it's not really an issue but when you're heavy, flying in high DA, it's very noticeable compared to the low-rpm powerhouse of a Lycoming.

Now as far as wear/tear goes, the rotorway engine is considered damaged if operated above 5,000 rpm as-is. There are likely many engineering-related modifications required to make the engine safe to operate at that high of an rpm (like different valve springs to prevent float). At which point, it may be better to spend that money on a Lycoming and figuring out the rest, since you'd have to change drivetrain ratios anyhow.

(12-31-2025, 04:15 AM)Graeme Smith Wrote: Just wondering if anyone has experience with running the RW 162 engine above the 4250 for extended time,

I am looking for what would happen IF the engine was run at say 5000rpm, continuously would it make more power, would it explode, would it last?

In this idea I am not using the FADEC system I am using the TBI system which I have proven at the regular 4250 rpm, and my outside scoop cooling system.

But just thinking outside the box.... what if a gearbox was designed with an output at 520rpm but the input around the 5000 would the engine be OK?

I am under the assumption you are referring to the "stock" 162 engine.  If that is correct I will make a statement regarding that assumption.
If my memory serves me correctly the 162 has a 4.0" bore, 3.28+- stroke and a 5.4" rod.  The cylinder head configuration is the limiting factor in the desire to increase the RPM in order to produce more power.  At 4250 the engine is below 85% VE and atmospheric pressure at sea level.  The short rod increases the angular velocity to a point of loosing power above 4000 RPM.  Camshaft cannot make up the needed increase.  At 5000 RPM the valve springs would be consumed prior to 500 hours.
That being said, not to be a pessimist but realist, the engine is a poor design.  The naturally aspirated 162, fuel injected engine averaged 123 HP at 4250.  Injector angles, atomization, compression ratios, all were incorrect and I won't even talk about the valve geometry.  
I have developed a better engine for the helicopter. I have three different versions.  N/A 4250/160HP, N/A 4250 175HP and a turbo version 3900 225HP.  All of these require a complete change of internals including crank, rods, pistons, cam, and injectors.  I, along with help from Kyle Carter and Brad Champlin have made a very good 160HP n/a engine using the FADEC that was used in the earlier 162's.  
Sorry for such a long reply

Thank you all who have replied,
and a special thank you to the guru of the RW engine Joe Huff!

My question was to see if the RW at 5000rpm would be able to run a generator, that would produce enough power to power an electric motor, that being said the 5000rpm was needed to get enough power from the generator and that power was enough to power the electric motor (axial flux technology) All of that was to eliminate all the RW drive systems and their associated losses getting a lot of power to the rotors.
For now I have shelved that idea till a future project, a 4 seat electric helicopter.

Now I am working out the details of a gearbox to eliminate the RW drive system. and have another engine in mind. 
The design will allow the RW engine to also be the powerplant but it will need a small reduction gearbox that would be bolted to the underside of the gearbox making the gearbox a 2 stage reduction (which we will work out how soon) that will match the engine we plan to use which has a continuous RPM at 2420 at 180hp and runs a turbo (the engine spins at 4500 with a reduction gearing already installed and proven on it)
we will still need to refine the connection of the engine to the gearbox via a centrifugal clutch, an isolating damper and a one way, all of which we have done on the Delta D2.
The gearbox will have a tail rotor output where the shaft drive will mount to the top of the boom at the bulkheads, and the tail rotor gearbox will use spiral bevel gearing with a hunting tooth design.

The idea is I would like to keep my brain working and this kind of a project does just that, I also have been introduced to some VERY clever aeronautical engineers during the Delta D2 project and they are still open to a challenge, so I am not alone yet.

So sometime in the next 6 months or so we will see how much of what I hope will happen, actually does happen. 
Also a completely new tail rotor system with composite blades will be driven by the T/R gearbox.

I do hope I am successful in making these upgrades available to all RW owners as I do believe in the experimental category and with now commonplace CNC machining, nearly anything is possible.