Yamaha RX1 Engines

451 posts in this topic

Posted (edited)

I ran into Steve and Yee Haw 5 at the Arlington Airshow in Washington State last week. I spent some time talking with Steve and watched him fly twice. What an airplane! What a performer! That Yamaha is powerful and runs real smooth. It takes a little finesse to start without a clutch but it was a real strong sounding engine. Steve said once he got the bugs worked out he likes it. Two areas he fought were carb venting and exhaust. He said once he vented everything to a common point it worked. He said he changed the exhaust configuration 4 times before he got it to work right. He said it's running very strong now. He said its a stronger runner than his hopped up Rotax.

20160708_112845.jpg

Edited by rvsimons

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Posted

Here is a short video I took of Steve's plane starting. I have one of him flying that I'll post once my kid gets home with his phone. My phone went dead. :(

20160708_113210.mp4

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Posted

Video won't play.  

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Posted

Got a link to that face book page?  I'm not on FB, but my wife is.  JImChuk

Im not a member either, Just type in wild west aircraft Face Book his page will show up and you can view it.

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Posted

I played it on two devices. Make sure your devices will play mp4 files. My devices were android phones.

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Posted

Won't play in the Chrome browser, you have to download it, and then if your machine has an mp4 codec it will play directly.

Mark

 

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Posted

RX-1 CPR Dyno.jpg

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Posted

Thanks for the chart, what rpms do you cruise at and what was your max rpm with the c drive.We have the c drive on  the engine but haven't started the engine mount yet

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Posted

Great, a hp conversion table! But for what exactly, a snow machine? Still waiting for some actual RX-1 aircraft application Dyno charts...

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Posted

dholly,

I don't understand your question. This is a dyno run of the engine for any application. It is raw torque and RPM numbers with the engine bolted to a dynometer.  what is a        "Aircraft application dyno chart" could you possibly be asking for real world numbers as far as airspeeds and rpms for a given airframe with this engine? If so what numbers would you like to see? I have a little bit of data of this engine flying in Steve Henrys Highlander and a number of different trikes and gyocopters. Just in general Steve is able to climb at a steady 1900 fpm from 1000msl. his WOT level flight is 124 MPH with the 3:1 ratio gearbox and slightly faster with the 3.47 ratio.  He takes off in less than 100ft. In comparison to the his past big bore 912s with nitrous the stock RX1 pulls harder on a pull scale and pulls harder on takeoff. Static thrust pulls were 580-600 lbs depending on the day. Those pulls were with a 80" X 46" Prince p-tip prop. Both highlanders weighed right at 700 lbs. I hope this info helps but If there are any other aircraft data points that you are looking at, let me know and I may have them.

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Posted

Those are about the same numbers I'm getting out of my 105 Zipper with a 78x48" Prince in the 700 pound Mangy Fox.  Sustained 1700-2000 climb, off the ground in less than 200', wide open speed about 120 mph. 

The numbers out of the Yamaha are exciting to see. With some more tweaking that will become a very viable engine.  I hope the availability of engine cores can be sustained. 

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Posted

I use the ceramic top pistons .  They expand at a far slower rate than Non ceramic top pistons . The steel cylinder liner takes several minutes to expand. The colder the tempeture the  longer it takes.  I recommend 2 minutes at 2200 rpm while taxi to the run up area.  Then at 4,000 rpm for 2 minutes. Then increase to 4500 rpm's for 2 more minutes. Then to 5000 rpm for the last 1 minute of your run up.  Now do your mag check & your fuel pump test.   Do not return to a idle if the take off is delayed by a landing Aircraft. Once on the runway use full throttle until airborne. If your clear of obstacles back the rpm  down 250 rpm or more.

 ( 90% of engines that fail the damage that caused the failure  happened while running at full power

You have only .003 piston to cylinder clearance. If you scuff a piston ( and  maybe not even knew that  you did )   and your cruising along 10 hours latter at 5,200 rpm 

and  the engine shuts down without know warning at all !!!!  EVERY GAUGE WAS READING PERFECT !!!   Once you scuff a piston please change it.

 If not it will do it again 100% for sure. 

3 out of every 5 582's that fail is the lower rod bearing. The second largest 582 failure is cold seizures.   It's not the engine's fault !!   WARM THEM UP PLEASE !!!

I have never had a single 670 seize & that's out of 250 + 670's that I have built.  .005 to.006 piston to cylinder clearance is the reason.

Every 582 or 670  I rebuild get ceramic top pistons. 

 

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Posted

Teal or Marshawk, any progress on the conversions ?

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Posted

I have the adapter plate and c drive on the engine but haven't started the motor mounts yet ,time is never on my side but hopefully in the next couple weeks will have some time to  built it, then comes all the wiring and plumbing etc

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Posted

Anyone doing this swap should definitely create a build thread.

Electronics, plumbing etc  will be very valuable info.

Saw a youtube video about a gyro running this engine. His digital speedo in the Yamaha cluster worked .

Is that common ?

 

 

 

 

 

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Posted

This is Steve Henrys engine install. He has a littlw over 60 hours on it. He reports it has as much power as a big bore 912 with a turbo. He recently installed the rk400 clutch and seems to be working good for him.

IMG_1375.jpg

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Posted

Any progress on Terry's plane? I will be following that closely.

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Posted

Yes, The RX-1 is temporally mounted and the new engine mount is almost done for Terry's Avid but Terry is having a bunch of things done to his so it might be down a little while.

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Posted

Any chance you are going Prescott for the AOPA fly in next weekend? Wife and I flying down to meet an old Airforce buddy of mine and Terry for the weekend.

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Posted

20160928_210806.jpg

3 people like this

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Posted

Terry's avid progress

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Posted

That thing is going to be like a helicopter.  Cant wait to see that fly.  Be sure to post performance videos.

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Posted (edited)

This is arguably a very nice adapter from SkyTrax.  Here's where Teal got his ideas:

Teal was considering buying a YG4 PSRU adapter from Mohawk Aero when he instead decided to design/fabricate an adapter for himself and for sale, and call it his own.  (The Chinese do this all the time but who cares so long as Walmart stays open?)  

Mohawk Aero Corp (MAC) got the idea from Rotary Flight Dynamics (RFD) in Florida.  They installed an Auto Flight PSRU on a fuel injected YG4 (Yamaha Genesis Extreme 4-cylinder) 2010-2011.  This was the first known YG4 EFI aircraft conversion in the world.  They got the idea from Todd Reich in Colorado who started putting YG3's on gyrocopters back in 2007. 

Mohawk completed the first ever YG4 NA (Naturally aspirated) aircraft, and began flight testing in November 2012. 

Both of these YG4 powered aircraft were tandem gyroplanes.  (RFD builds Dominators, Mohawk is an Air Command dealer.)

Mohawk Aero has flown hundreds of trouble-free hours on their RX1 aircraft conversion.  You can visit them at  MohawkAeroCraft.com or email info@mohawkaerocraft.com.

 

 

 

 

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PRA Cover June 2013.jpg

Edited by Mohawk Aero

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Posted

Yesterday I visited this forum for the first time and read the questions raised here concerning Yamaha Genesis Extreme 4 cylinder (YG4, what I coined years ago as a nickname for these monsters) electronic reliability and issues concerning feedback loops on the 2003-2005 carb and 2006 - present model EFI engines. 

I read through the entire thread and couldn't find an answer to your questions.

So I joined this forum to give it to you straight from the horse's mouth, FYI. 

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *

Mohawk Aero was the first shop to install an RX1 (naturally aspirated) engine on any type of aircraft. Rotary Flight Dynamics (RFD) in Florida was the first to install an Apex (EFI) on an aircraft, and theirs was finished and flying well ahead of ours.  RFD experienced a great number of setbacks due to the feedback loops wired into the EFI system, whereas the Mohawk Aero ran perfectly right out of the box, and never had any problems whatsoever.  Well, almost.

After 20 hours I was flying several miles away from KCTJ at sundown, enjoying the magnificent view as the sun emblazoned the sky in reds, purples, yellows and oranges.  This is why I came to fly in the first place, after all.  Force of habit, I glanced down at my panel and the Yamaha sled tach, what the manufacturer calls the multi-function display, or MFD.  Nothing.  Zippo.  Zilch.  Nadda.  WTF?  Engine was running just fine.  No missing, no loss of RPM.  I headed back to the RW like any sane pilot would do immediately.

Upon post-flight inspection I found the voltage regulator (VR) HOT, as in fried and I knew it was shot at once.  I metered the battery and it checked out at 11.8v, and upon further testing found that when the regulator goes dead the MFD will continue to function up until a point when the battery drops from 12.0v to 11.9v, then it shuts down. 

Next I discovered that with the engine running I could disco not only the VR, but also the ECU and the engine would continue to run perfectly fine at all RPMs!!  This was great news, and I was very happy to discover that the individual spark plugs are fired and timed directly by the mag to each of their individual (4) coils, which are recessed in deep sparkplug wells in the top of the head.  In other words, you could lose not only the VR and the ECU, but also one or two coils/plugs and STILL get back to the airport!  

So who cares if you lose the ECU?  The VR?  A couple of plugs or coils?  Fuhgedaboudit.

Inquiring minds may want to know how I lost the VR in the first place, so here it is:  These engines have liquid carb heat that kicks in after the engine gets running.  But did you know they also have electric carb heat?  Yep.  That is for starting the engine at temps well below freezing. A connector got bumped during one of the innumerable prototype assembly fitting install/removals and broke.  I knew about it and had repaired it, but it failed in flight and the connector went to ground.  Lessons learned:  Don't bother with the electric carb heat unless you plan on starting the engine in -20F temps.  It is a single point of failure you don't need, and SPF you don't need get rid of it.

I have since removed the electric carb heat wiring in all of my subsequent installs. 

This is but one tiny nugget, one example of advice I offer not just my paying customers, but to all - and freely.

I have offered such sage advice publicly over the years which has been silently taken in and used with no ackowledgement nor gratitude.  Things like exhaust tube length (look at the pix of Teal's first build and compare to his later exhaust congifs), carb tuning and jetting, correct intake plenum pressures and configs, oil breather advice, oil level advice (yes, you can blow up the engine on take off if you have over-filled your reservoir or don't breath the engine properly).

 

 

 

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Posted

I can't say I am on the edge of my seat following this engine choice, but I do follow it with interest as it finds it's way into tube and fabric aircraft. I hope it works out and appreciate MohawkAero (how about a 'proper' name?) joining the forum and contributing to the thread. IMHO, all information now and in the future is welcome in my eyes.

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