Anything new on Yamaha conversions?

[NoWingsAttached]

I think I'll check back over Ron's extensive thread and revisit his build, look over the attachments for all the gadgets and doo-dangles I have to finish up and see what the solutions he came up with look like. Then, too, I have a lot of pics of Ernie's project I can use for helpful ideas now. It sure is fun to put this together. Taking everything apart getting it out of the sled, and cleaning it all up was such a dirty, knuckle-banging task, it just makes all this (now clean) work seem so much more fun. But everytime I touch something else on the Air Command AF, yuk. My hands come away blackened with oil and dirt. Still a LOT of clean-up left to do on the rest of the AF.

Just spoke to the water jetting shop, they are back from vacation and I should get new pricing for the re-worked drawings tomorrow.

They had a big tent sale over at Harbor Tools this weekend, i had a ball on my Birthday shopping there. Got a bunch of new polishing stuff to help make the aluminum look its best.

New sanding belts, dust masks, and even picked up an infrared hand-held gun-type digital thermometer so I can calibrate my heat sensors and gauges from now on. Not that I've ever had problems with hot engines and rings melting before or anything...

I explained to my 8-yr-old daughter that tools are daddy's version of "toys". SHe thinks it's a little crazy, and cant' understand why i would rather play with my toys than play Monopoly with her...

I try to carve out time for her everyday, and still keep this project advancing as well as I can.

[NoWingsAttached]

Originally Posted by Racer

Greg, It was nice talking to you today and congradulations on your buy.
I do not have any 4 cylinders here but I will help you if I can.
Post your progress, I would like to keep up on your build.
Racer

Todd

How are ya doing these days? I need some plastic sidecovers from a sled, can you sell me one or a couple pairs? Dont' be stingy, sell me some, I need them fast. Time's running out on me, my wife is donating a kidney to our daughter July 5th. My company got bought by another, the take-over is taking place July 1 and I have to get my insurances switched between now and then. OMG I just found out about the transplant dates last Friday, 6/8.

I am $**tt**g myself. Georgia Department of Treasury just decided they want a hand-written copy of my 2011 taxes, immediately. THey owe me $790, they are stalling. THey always do this to me.

THe dialysis vendor for monthly supplies was late submitting their billing to the hospital kidney fund for timely invoicing. THey got stuck with almost $30k in costs the hospital says were billed late. Some new beancounter decided to impress someone with her collection skills. She sent ME a bill for $29k My employer hired a private advocate to beat up the vendor. I have all that paperwork to fill out now. Stacks of it.

I just got off work, I started at 9:00 am Monday, a 20-hour shift, and I am 58. I woulda made a good doctor. My wife is probably wondering why I am not coming to bed. That's because I am still wide awake and can't sleep now. My wife is probably wondering why I am not coming to bed...OH! Now I get it. Riiight. Well, I am slowing down a bit, after all. But I still ain't THAT old! BYE! I have a nice bed to go to now...mmmm

[GyroRon]

oil tank should be high enough the that oil can gravity feed into the engine, so the engine has oil at start up to lubricate everything

[NoWingsAttached]

I finished figuring out the cooling and oil lines last night. I cleaned them all up with WD-40, and they look brand spankin new. I buffed any corrosion off the clamps, and all the connections to the engine and pumps have been completed. The large, round drum-shaped object to the left of the oil filter is the oil cooler. THe hoses connecting it are not oil lines, they are coolant in/out

This part of the build looks surprisingly neat and compact, not a lot of helter-skelter in the hose rountings as you can see. Everything that dives down from the top to the bottom is at the front of the engine, and fits neatly between the two forward engine mountings.

Using the stock factory hoses you can see how all the little bends and turns are form-fitted to route beautifully.

I am counfounded by a 1/4" hose that connects from the carb intake silencer (not shown) to the uptake area of the WATER PUMP! A vented water pump? Never heard of such a thing. IT INTRODUCES air into the cooling system!?!?!?! Seems very strange to me, but you can see the plugged end of that hose next to the much larger, plugged end of the crankcase vent condensor, upper right corner of the engine block.

So, what do you guys think? I mean, this is it. The hoses are all attached and routed.

The only thing left to do as far as hoses is mount the radiator and run the two hoses to it, and finish cleaning up and mounting the oil Tank.

[opsled]

I'd have to go raise the roof on my RX1 to be sure but are you sure that 1/4" hose isn't supposed to go to the carb rack? Coolant does go through to heat them and one of the lines to hook up the rack is right in that area.

Also. The crankase vent can't be capped to run. I've got a small vent/filter around here somewhere to replace the stock plastic bottle you are calling a condensor. If I can find it I'll post a pic.

Looks good otherwise.

opsled

[NoWingsAttached]

Originally Posted by opsled

I'd have to go raise the roof on my RX1 to be sure but are you sure that 1/4" hose isn't supposed to go to the carb rack? Coolant does go through to heat them and one of the lines to hook up the rack is right in that area.

Also. The crankase vent can't be capped to run. I've got a small vent/filter around here somewhere to replace the stock plastic bottle you are calling a condensor. If I can find it I'll post a pic.

Looks good otherwise.

opsled

Thanks for your response The coolant hose to the carbs is about 5" long and goes directly to the coolant piping on top of the valve cover, not the water pump. in the last picture on post #289 you can see part of it in the upper right corner of the frame, exiting down and to the right. The stoppers on the vent tubes are temporary, to keep the dust and moisture out of the engine during the build project.

[opsled]

Originally Posted by NoWingsAttached

Thanks for your response The coolant hose to the carbs is about 5" long and goes directly to the coolant piping on top of the valve cover, not the water pump. in the last picture on post #289 you can see part of it in the upper right corner of the frame, exiting down and to the right. The stoppers on the vent tubes are temporary, to keep the dust and moisture out of the engine during the build project.

Yes, The 5" hose is one of the carb inlet/outlet coolant hoses. The other hooks to the bottom of the carb rack right in the area of the hose you are wondering about. I was thinking it may be that lower carb hose.

My memory (not always up to snuff) is that the air intake silencer only has two hoses hooked to it. One is the larger crankcase vent hose and the other is a smaller drain hose hooked to the bottom to allow any moisture that may accumulate in the airbox to drain.

Again, my memory might be off.

opsled

PS, That's a great engine and I'm sure you'll be happy with it. They can really crank some RPM's but pull like a mule way below the redline. Many in the world of sleds clutch the engine to rev higher to get it in it's max hp range in the expectation of being faster. In stock form they are clutched to hold the engine at a lower RPM that is more in line with where it makes it's max torque. I have left mine stock and although a clutched "up" sled is some what quicker off the line because of the higher rpm my stock one will quickly catch up and achieve top speed faster once aero forces start to put a load on the machine. It also seams to be able to pull a higher top speed because of it.

Not that it means all that much for applictions like this but my experiance with them tells me that they seem to be able to do more work at a rpm that is more in line with torque as opposed to a two stroke that likes to work at an rpm that is more in line with HP.

Cool engines.

[NoWingsAttached]

Originally Posted by opsled

Yes, The 5" hose is one of the carb inlet/outlet coolant hoses. The other hooks to the bottom of the carb rack right in the area of the hose you are wondering about. I was thinking it may be that lower carb hose.

My memory (not always up to snuff) is that the air intake silencer only has two hoses hooked to it. One is the larger crankcase vent hose and the other is a smaller drain hose hooked to the bottom to allow any moisture that may accumulate in the airbox to drain.

Again, my memory might be off.

opsled

PS, That's a great engine and I'm sure you'll be happy with it. They can really crank some RPM's but pull like a mule way below the redline. Many in the world of sleds clutch the engine to rev higher to get it in it's max hp range in the expectation of being faster. In stock form they are clutched to hold the engine at a lower RPM that is more in line with where it makes it's max torque. I have left mine stock and although a clutched "up" sled is some what quicker off the line because of the higher rpm my stock one will quickly catch up and achieve top speed faster once aero forces start to put a load on the machine. It also seams to be able to pull a higher top speed because of it.

Not that it means all that much for applictions like this but my experiance with them tells me that they seem to be able to do more work at a rpm that is more in line with torque as opposed to a two stroke that likes to work at an rpm that is more in line with HP.

Cool engines.

Aha. I have much to learn about CVT transmissions, and I want to experiment with using it on a jump or near jump take-off gyro after I get this project in its current design flying and tested. The CVT loading combinations that are available are so many, so varied, it is expected to be a rather lengthy process to find a combination that is suitable for the gyro. I think a lot of the issues reported about excessive belt wear on a CVT conversion project may be due to prop harmonics bumping into the engine harmonics at the redrive interface, and/or slight misalignment of the pulleys/belt. So, with these issues in mind, I am going the straighter, shorter route for now using the geared redrive unit.

I still can't seem to locate an opening in the lower carb rack for the darn hose, other than the one in the silencer. I can pop off the carb rack in about two minutes easily enough, so it looks like I will be taking it off tonight to look for one.

I've attached a HP chart a Yamaha salesman sent me last year. I can't locate a torque chart, but with this HP curve, I don't really need to see it.

This isnt' a scientifically accurate chart, it is for sales purposes only, but it provides a fairly accurate idea of what's going on with the power band. Yamaha never published their HP ratings for this motor in 2003, but it is fair to say it's 150hp peak.

MY GAWD! Are you kidding me? I've drawn in lines so you can see where everything lines up on the X-Y axiis. We are talking about MAX HP less just 4 HP coming in around 8200 engine rpm, and 6890 at the geared output shaft. In other words, when this engine is loafing at 75% of it's rpm range, it is putting out 97% of its available peak HP.

So from 8200 to 10,700 rpm, the engine output is all about increased speed, not HP. On the ground that is very useful, but with an aircraft application increased engine rpm doesn't do much to help performance. The engine should be bullet-proof at the loads and lower rpms in the 8000-9000 rpm range.

With this kind of power band, it will be very important to take care not to over-rev the prop and tear it apart. THink about it: If you set the prop pitch to max HP, your margin of error is only 1.5% before you overrun the engine rpm and rev the prop way past cavitation, which with these loads can rip the prop blades out of their roots pretty quickly. In other words, you can't really set up the pitch to govern the engine rpm safely at all. You need to pitch the prop for your throttle stops or for redline and throw the book out hte window that tells you to pitch the prop just to the point where it loads the engine so that it can't go any faster. TOO risky in this conversion. But that is still the best baseline to start out with, and if you're mindful during test and tune flights it should be fine.

I'm getting way ahead of myself...Need to get my adapter back from the shop!!!

[opsled]

That second port for the carb coolant line is on the engine side/bottom of the # 1 carb as I recollect. I hook it up before I put the rack on the engine. Hard to get at otherwise.

Here is a Dynotech evaluation from back in 02. The machine was new and hp/tq was expected to rise after breakin. They also had a carb issue that they didn't find out untill after a second test a year later. In the second test HP went to over 140 and TQ to over 80. The curve was very similar to the first test.

Could post it for you too if you want it.

opsled

10/2/02
2003 Yamaha RX1 stock evaluation.
From Jim Czekala, www.dynotechresearch.com
Comments on the dyno performance of our first production RX1.
SuperFlow 901 engine dyno, connected directly to RX1 engine output shaft
Air temp: 75 degF
Water temp: 180 degF
Oil temp: plenty hot
Baro: 29.1
Jetting appeared spot-on for 75 degrees F (temp measured beneath the airbox at the
airbox opening. BSFC was about .40 lb/hphr at midrange, WOT, then enrichened at high
revs to about .50 (safe on 4-cycles). Crankcase blowby measured 2 cfm which equates to
about one percent leakage (considering the engine was consuming 180+ CFM.).
We have dyno experience with Bender Racing's Yamaha FZ1 motorcycle. Because the
FZ1 motorcycle engine is reportedly similar to that used in the RX1 snowmobile, Bender
used this model bike this past summer to prototype and endurance test a new
turbocharger system for the RX1. On our SuperFlow rear wheel eddycurrent roller dyno,
Bender's stock FZ1 made 127 corrected HP at the rear tire during baseline testing (and
lost 2-3 HP when the quiet stock muffler was replaced with an obnoxiously loud
aftermarket glasspack). If the RX1 engine is, indeed, the same as the FZ1 we would have
expected to see more than 137 HP from the RX1 engine. Typical motorcycle driveline
loss (crankshaft-clutchbasket-countershaft-output shaft gears /rear drive chain and
sprockets) is said to be higher than the 8% loss that 137/127 works out to. We would
normally expect closer to 13% loss, which would result in 146 engine HP.
Though this is our first RX1, we don't think this is an anomaly because Rich Daly at
DynoPort recently tested an RX1 with nearly identical test results.

Though our peak HP was less than expected, torque/ HP at low revs was very high in sled
terms. So high, in fact, that our dyno absorption unit could not hold the engine below
5000 RPM! Two-cycle sled engines are "off the pipe" at clutch engagement, meaning
without the supercharging effect of the tuned pipes helping at low revs, even 1000cc sled
engines are like overgrown chainsaw engines, and can be easily controlled on our dyno at
3-4000 rpm, WOT.
We also checked the baffling of the airbox as follows:
1) removed shelf and foam, peak airflow dropped to 172 SCFM, lost HP throughout the
powerband.
2) removed foam only, baffle in place, airflow peaked at 179 SCFM, HP slightly less than
stock.
Conclusion: stock airbox is quiet and excellent design.

EngSpd STPTrq STPPwr A/F BSFC Air 2 Fuel B

RPM Clb-ft CHp Ratio lb/hph scfm lb/hr

5200 60.6 60 11.6 0.52 74 29.2
5300 60.1 60.6 11.6 0.52 74 29.2
5400 60.6 62.3 11.7 0.5 74 29.2
5500 61.4 64.2 11.7 0.49 75 29.4
5600 61.5 65.5 11.7 0.48 76 29.6
5700 61.9 67.2 11.8 0.48 77 29.8
5800 63 69.5 12 0.46 79 30
5900 62.7 70.4 12.4 0.45 80 29.5
6000 63.1 72.1 12.8 0.43 81 29.1
6100 63.7 74 13.3 0.41 83 28.6
6200 65.5 77.4 13.9 0.39 85 28.1
6300 66.9 80.3 14.6 0.37 87 27.3
6400 67.7 82.5 15.1 0.35 89 27
6500 68.6 85 15.3 0.34 91 27
6600 71.9 90.4 16.2 0.32 95 26.9
6700 73.2 93.4 14.5 0.37 101 31.9
6800 73.8 95.5 13.9 0.39 104 34.3
6900 74 97.3 13.7 0.39 106 35.5
7000 74.8 99.7 13.4 0.41 112 38.4
7100 74.5 100.7 13.4 0.42 116 39.7
7200 74.5 102.1 13.3 0.42 117 40.2
7300 74.8 104 13 0.43 119 42.1
7400 75.5 106.3 12.7 0.44 122 44.1
7500 75.8 108.2 12.6 0.44 124 44.8
7600 76.1 110.1 12.8 0.44 126 45
7700 75.9 111.2 13 0.44 129 45.2
7800 74.9 111.2 12.7 0.45 131 47
7900 74.6 112.2 12.8 0.45 132 47.3
8000 74 112.7 12.8 0.45 133 47.6
8100 74.3 114.6 13 0.45 135 47.5
8200 74 115.5 13 0.45 137 48.2
8300 74.4 117.5 13.1 0.45 139 48.7
8400 74.8 119.6 13.1 0.44 142 49.4
8500 74.7 121 13 0.45 143 50.5
8600 75.1 122.9 12.9 0.46 146 52.1
8700 74.9 124.1 13 0.45 149 52.4
8800 75.4 126.4 13.2 0.45 153 52.9
8900 74.5 126.2 13.3 0.46 158 54.5
9000 74 126.9 13.3 0.46 159 54.6
9100 74.6 129.2 13.4 0.46 161 55.3
9200 74.5 130.5 13.5 0.46 164 55.8
9300 74 131 13.5 0.46 167 56.4
9400 73.5 131.5 13.5 0.47 169 57.2
9500 72.5 131.2 13.4 0.47 170 58
9600 71.6 130.9 13.3 0.48 171 58.7
9700 71 131.2 13.3 0.49 171 59.2
9800 70.8 132.1 13.1 0.49 172 59.9
9900 70.1 132.2 12.8 0.5 172 61.6
10000 69.5 132.4 12.5 0.51 173 63
10100 69.1 132.9 12.5 0.51 173 63.3
10200 69.1 134.2 12.6 0.51 175 63.7
10300 68.8 134.9 12.7 0.51 177 63.9
10400 69 136.6 12.5 0.52 179 65.3
10500 68.1 136.2 12.5 0.52 179 65.5
10600 66.9 135 12.5 0.53 181 66
10700 66 134.5 12.2 0.55 181 68
10800 65.4 134.4 12.1 0.55 181 68.5
10900 64.7 134.2 12.2 0.56 183 69
11000 63.8 133.7 12.1 0.56 182 68.9

[NoWingsAttached]

(It's Flag Day, and I am 100% USA Patriot)

Phil:

HEY, THANKS FOR THE TIP!!! I found that little hose nipple hidden behind an electrical connection, and you're right, it is REALLY difficult to get the hose clamp in place with the carbs attached - but I managed with a pair of long hemostats. Silly me, I'm just going to remove the carbs again anyway to try and detail the various parts and clean off the corrosion on them.

The data you've posted, as it relates to the airbox, is of particular interest. I've been wondering how much the air box affects performance, and you have shown that it is significant. What are you referring to when you say "shelf", is that the partition inside the plenum, or is it the entire airbox?

If you/they removed the airbox, did you remove the rubber carb boots that are seen in the photos I posted above?

I am thinking that the airbox may reduce turbulence, and that the rubber boots act as velocity stacks to improve flow. If the airbox were replaced with velocity stacks of proper length, I wonder if that wouldn't result in similar flow numbers as leaving the airbox in place? It is amazing to me that such things as removing the foam actually DECREASES power! Yamaha must have spent a lot of R&D $$ getting this thing designed and engineerd just right, eh? WHen I see the detail in the parts on this magnificent example of a motor, I am not surprised at the attention to the little things like that that peak the power perfectly, as it is, straight from the factory.

A few things jump out at me here, regarding the numbers provided.

1. Those torque numbers are really w-i-i-i-i-i-de! Wow. THe torque curve climbs, drops off a bit, climbs again and then drifts down? I am going to drop these numbers into a chart and post it. This is really unexpected. I mean, I knew the low-end torque was incredible from riding the sled around on the pipeline ROW in my backyard before I removed the motor, but this is really new and strange to me.

2. Can you explain the abbreviations?

3. Lower-than expected HP: I think the data is accurate, I am not surprised that it indicates lower than 150HP. I would have been surprised if it didn't.

a. First, reported was a retest after some tuning that resulted in a ~ 3% increase in power. The engine was found to test at (let's nail down a number for the sake of discussion) 142 HP vs 138 previously.
b. With every test there is a margin of error that must be included to validate it. There is no such thing as an absolute value in any test data, but rather a range of values wherein reality resides. That margin of error is missing, so we must extrapolate from past experience. This is a mechanical, spring-loaded device, testing a mechanical device. Typical margin of error in most any spring-loaded test device of this type of application is at least +/- 3%, often more like 5%. Let's go conservative and call it a 3% margin of error in the data to avoid controversy. That makes the range of test data at the last reported output of 142 HP a range of 138-146 HP.
c. Next, omitted in the report is air density. However, temps are reported. We can throw another 3% adjustment in here to allow for maximum air density due to temperature. That raises the max HP range to 142-150.
d. Finally, the altitude of the Dynotech test facility, located in Batavia, NY, is 1000' ASL. A 3% increase in HP must be added to bring it in line with the baseline, universally accepted, Mean Sea Level air density for rated maximum HP - all manufacturer's reported data for an engine product.

Which conservatively brings us to 146-154 HP, so let's just call it 145-155, easier to digest.

I hope I can get this thing wired up and geared down soon. I want to start it up with a prop attached sooooo bad!

[opsled]

All that info I posted came from Dynotech. They are a leading independant dyno shop and test sled engines in all forms from stock to full mod stuff. They have no reason to fudge numbers so their results are fairly accurate and a good place for the average consumer to get truthfull results. Many manufacturers of engines and performance kits like to use them because of that and many won't for the same reason. If a person/company has something to hide in the claims they make about a product or secrets in design Dynotech will find and can expose them. That won't work for those who are inflating claims or those who are trying to keep good inovation from being pirated so they don't get to test everything. They are a good company with accurate numbers that can be trusted.

That being said conditions do play into those numbers. That test was done on a brand new sled. They did find an error with that test in a subsequent test on the same sled that boosted the results and moved max TQ to +80 and max HP to +140. That and the expectation of a + 10ish hp increase after breakin should put most of these engines around the 150hp mark with good conditions.

Any airbox will play into how the engine runs and Yamaha does the work to get them right. There are mods that can be done that are claimed to increase power and many run pods. All my stuff is stock so I can't be of much help but you can go here http://www.ty4stroke.com/ and learn a ton about options that may work best for you.

What get me is the broad TQ range on these things. Look at the +70 numbers in comparison to rpm and HP and it's quite good. The power to recover and accelerate under load is very high in a wide rpm range. If you notice the TQ starts to drop off quickly after it reaches max HP which is why I think they perform better when working at an rpm that is closer to max TQ. I bought mine with 500 miles on it and it had been clutched up to run at a higher RPM. It was quick and pulled strong but was jumpy and fuel consumption was way below where it should have been. I rode it that way for a few hundred miles then decided to put it all back to stock. It didn't jump off the line like before but was much smoother, seemed to even pull stronger and fuel consumption went way down. I had run 1000ft radar runs with both setups and it was faster stock. Early on about 115mph on the dream meter was about it. It seemed to be getting better with age and the last time I really had a chance to open it up was after it had close to 3K on the clock. The speedo was bouncing off 127mph then so they do get stronger with some time on them.

I'll have to look at that second dyno test they did. It's results were much better than the first.

Good luck, opsled

[NoWingsAttached]

I can't imagine 127mph on a sled! I think I might have hit 70 once...back in the 70's! We had a few years where they trucked in huge loads of snow to our local Michigan horse track, Northville Downs, (about 20 miles NE of Ann Arbor) and raced around the 1/2-mile oval. Man, was THAT ever cool to watch!

[NoWingsAttached]

The Yamaha handbook I downloaded in PDF from Ebay right after I bought the sled is SOOOOO worth the $7.00 I spent to DL it! Remember, it's been two years since I pulled the motor...things get misplaced and forgotten, even tho everything was numbered and labeled as I did the extraction. I just now printed out the last 15 or so pages, which show all the details of where hoses, electrical go to make sure I get the wiring harness hooked up to everything correctly, and to know what I DON'T need etc going fwd. I did have the laptop out in the garage, but I think it is easier now just to have all the pages open in front of me now, easier to flip back and forth.

I cant' imagine anyone trying to do a Yamaha conversion w/o it.

The adapter drawings are finally cleaned up and proper quality ready to upload to the water jetting software driver. I should have the redricve adapter in my hands next week!!! I am going to drive up to Buford to pick it up, and meet the guy personally. He may be able to have a partner turn some custom studs for my Arrow engine project as well.. I have not been able to find exactly what I want off the shelf, so it is probably just easier to have a machinist make what I want. that is another thread, another story, another project, another day.

Every time I look at this thing, the first word that pops into my head is "wicked".

This thing is just wicked.

Gyro to be duly christened at launch.

[NoWingsAttached]

Got wiring labeled and routed. Got the sled, tractor and gyro to fit inside. my neighbors will be happy.

[NoWingsAttached]

Originally Posted by GyroRon

oil tank should be high enough the that oil can gravity feed into the engine, so the engine has oil at start up to lubricate everything

I couldn't agree more. And in the event you have oil pickup pissues while flying, always better to have gravity on yer side. That, plus the OEM hoses fit real pretty when it (oil tank) hangs high up on the mast like.