RV9 200HP Yamaha Sidewinder

[lr172]

Originally Posted by Dad's RV-10

According to this article, the pistons are forged.

No real surprise. Forged pistons are cheap insurance in boosted or NOS applications.

Larry

[rv6ejguy]

Forged pistons and oil squirters. That's what you need to make it reliable at these specific outputs.

Whoever wrote the article didn't research production turbo engines with ITBs very well.

Lotus blew through twin Dellorto sidedraft carbs on their 2.2 turbo way back in 1989.

Nissan produced ITB turbo versions of the SR20 and RB26 over 20 years ago if I recall correctly.

I could be missing some others but Yamaha is hardly the first and despite the hype in this article, there is no new technology here. Nothing really different from state of the art automotive turbo engines from 25 years ago.

[charosenz]

Teal,

Great to hear about this. I can personally appreciate how much work it is putting an alternative engine in an RV....and how much fun it is.

It is good to hear people offer support and encouragement and I hope people continue to respect it is your choice and keep the parental cautionary verbage to a nano-minimum.

I know here in KY, Justin Richardson, who just put a Sterna prop on his RV. I can't remember which model of RV he has. Ill encourage him to jump on here and comment about the prop.

[Ed_Wischmeyer]

It is good to hear people offer support and encouragement and I hope people continue to respect it is your choice and keep the parental cautionary verbage to a nano-minimum.

There's lots of newbies who are in over their heads, so providing unbounded enthusiasm can show up more accidents and in higher insurance rates for all of us, maybe in more closed airport.

"It's a homebuilt and you can do what you want... but the laws of physics don't care what you want."

Ed

[dlomheim]

Originally Posted by Teal

It climbs really, really good up high. But Cruise speeds are not as good as they should be. I feel that I am running out of propeller surface area, Not pitch because I can continue to increase pitch and still load the motor but increased HP is not equating to increased speed. Airmaster tells me this is the largest blades they can offer at this time. The highest that I have taken it was 15.5k and it will still climb around 1.5-2k ft per min. at 15k I think I was still able to make 44INhG manifold pressure. I am considering trying a fixed pitch propeller that performance up high. Sterna is telling me that they have a blade they want me to try. Anybody have experience with them?

What diameter prop are you running? When 2.85 PSRU was introduced for Mazda rotary engines, that required a longer prop to absorb the extra hp produced; and many guys ended up increasing their prop length to ~76 inches.

Doug

[Teal]

currently 67"

[Teal]

Just a follow up to my cruise speed numbers. Currently I have been leaning out just a little bit and experimenting on longer trips with altitudes and cruise speeds. My last trip I was at 164KTAS at 12kft burning 8.1 and AFR of 13.5. All EGT's were around 1380f.Manifold pressure was 36INhG, throttle position 36%. At 9gph and 40INhG manifold it was at 168KTAS. At 14000 ft it was about 3kts faster for same fuel burn. but normally I like to not have to use oxygen so I stay around 12kft.

[titanhank]

Nice job. Finally an alternative engine that can provide the performance of a lycoming. If you have a low pass video, i know everyone would love to see and hear it. I bet it sounds great. With the price of lycomings these days, i just can’t justify building anymore new planes.

[koupster]

Originally Posted by Teal

Just a follow up to my cruise speed numbers. Currently I have been leaning out just a little bit and experimenting on longer trips with altitudes and cruise speeds. My last trip I was at 164KTAS at 12kft burning 8.1 and AFR of 13.5. All EGT's were around 1380f.Manifold pressure was 36INhG, throttle position 36%. At 9gph and 40INhG manifold it was at 168KTAS. At 14000 ft it was about 3kts faster for same fuel burn. but normally I like to not have to use oxygen so I stay around 12kft.

Teal,
You may have found a bit of a sweet spot at 164 KTAS in cruise. You added 0.9 GPH and only got 4 more knots (2.4% more speed for 11.1% more fuel).

I fly my RV-6A (O-360) at 155 KTAS (11,500 ft MSL) burning a bit less than 8 GPH at approximately peak EGT (it's carbed). You're already doing better than I on a MPG basis.

[pjc]

Teal,
Very interesting project. I wish you much success.

Are you using the OEM ECU hardware (and reprograming it) or a 3rd party ECU ?

What boost control scheme are you using ? Is the waste gate mechanically controlled, or controlled by the ECU?

Are you using the OEM knock sensor and adjusting timing in the ECU ?

How about the O2 sensor — using closed loop AFR control?

Peter