Last Subie Flight of 2007

[clarkefarm]

[David-aviator]

Good job finding your way back to the airport in the glider, Rupert. Good luck with the replacement engine.

[rv6ejguy]

Glad you made it back to the runway Rupert. I think you are far better off with stock Sube internals. Those Motec ECUs are pricey but nice!

[clarkefarm]

Thanks David & Ross.

Will report on performance when I return. The NSI motor dynoed at 160 hp @ 5,800 rpm at the prop flange and was good for 155 KTAS at 8,500.

I think that a SOHC EJ25 is meant to develop 170 hp but no doubt there will be losses so hopefully performance will be similar.

There is a fair bit of weight in my installation:
Bare engine 195 lbs
Engine in FWF assembly including oils, gearbox & coolant 379 lbs
Exhaust system 18.3 lbs
Prop & spinner 30 lbs

I am thinking of going to integral coil/plugs to get rid of the two heavy Electromotive coil packs. The other heavy item is the two radiator fans but at the moment they are helpful for ground running. I intend to improve my cowl outlet set up so might be able to ditch them also.

How are you going with the cooling for the 10 Ross ?

Rupert

[rrnixonjr]

Ross,

What do you think about the new 3.6 liter subaru engine? Same dimensions as the 3.0 but with an improved cooling system. Maybe weight is the same too. Sounds like a better mousetrap down the road. Just needs a turbo and after market fuel injection. Any thoughts?

[rv6ejguy]

On the -10 I have a ventral radiator in a dedicated duct with controllable exit door like a Hawker Hurricane. I also have a cowling mounted barrel heat exchanger which can either divert hot air overboard for extra engine cooling or into the cabin for heat.

On the new 3.6, I think this finally has enough displacement to do the job in atmo form to compare with Lyco 360s turning reasonable rpms. With forged pistons and turbos, this would be very competitive with an IO-540.

All EJ/ EG/ EZ Subes have well designed internal cooling systems- the best I've seen on any engine in fact. Fuji went to great pains to make this right. We just need to get rid of the coolant heat efficiently with properly designed radiator systems. Mine runs very cool now in the -6A. I think I finally get it.

[Rhouse9044]

I have been flying my RV9A N462BD since it was signed off in June. I have an Eggenfellner 2.5 SOHC naturally aspirated with some minor mods- a mild port job on the heads, three angle valve seats, and a ram air induction with a K&N filter. I currently have 125 hours on it. I have been using it to commute to my job in Seattle from my home near Spokane, but the continuing series of storms moving across the area has put a crimp on that. I managed after two tries to keep my home grass airstrip plowed clear long enough to get the plane home Dec. 24th. I am going to park it for a month or so to install the Gen. 3 gearbox and install the main gear fairings.
I have been happy with the performance so far. At 8,000' I get 140 knots at 2,400 prop RPM with the main wheels and attach brackets hanging out in the wind. My goal at the start was a 150 KTAS cruise speed, so I'm almost there. Climb performance is very good. I timed a climb from sea level at BFI to 11,000' at full gross (mine is 1,800#) in twelve minutes eighteen seconds at ninety knots. Not O-360 territory but still pretty good compared to the Cessnas I used to fly. I think I'll get a couple hundred additional FPM from the 2.02 ratio gearbox and maybe a knot or two in speed. I think these four cylinder engines are a perfect match for the RV9 and with a little more massaging I think I'll end up with very similar performance to the O-320 Lycomings.
Bob House

[rv6ejguy]

Thanks Bob, those are pretty darn good numbers for a 2.5 at 1800 lbs.

What prop do you have?

I too think the 2.5 is a lighter, better match for the RV9 than the EZ30. Too bad they are not being offered anymore.

What is your empty weight?

[Rhouse9044]

I have a MTV-7-C prop that I bought from Eggenfellner Aircraft. The only drawback to it is that it doesn't make any additional thrust above 2,500 prop RPM. Running it at the rated 2700 prop RPM gets no additional FPM in climb. That may change with the 2.02 gearbox and 400 more engine RPM. The theory is that more RPM & therefore power will keep the prop pitch in a more efficient range. This engine runs quite happily and very smoothly at higher revs.
My empty weight came in at 1,170# minus the wheel pants, with a full IFR panel, Aero Classics interior, and lots of soundproofing. I installed my Super Trap muffler just aft of the rear baggage bulkhead in an effort to reduce noise, but then discovered as have others that simply installing a tailpipe with a downward bend is more effective. I am going to move the muffler forward and save the weight of 5' of exhaust pipe I have hung under the fuse now. I am going to move both batteries from just aft of the firewall to just aft of the baggage bulkhead. The plane flies better with a more aft CG and I might gain a little speed. I'll weigh the plane again when I finish my mods and post the results.

Bob House