Sled engines

N962GT

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The Predator ...

I don’t know anyone who has had a trouble free Yamaha sled engine in a gyroplane experience although I suspect there are some.
Swapping out one Lycoming for another one a bit bigger is not cutting edge nor breaking news, nor does it qualify you as a builder, an innovator, or anyone with the proper expertise to seek out and rely on for build and/or conversion advice.

Pat yourself on the back.

As far as this thread topic goes Vance has nothing to offer but stale, self-important opinions, backed up with zero experience.

Opinions are like elbows...

That VB still maintains today this BS that, "I don’t know anyone who has had a trouble free Yamaha sled engine in a gyroplane...", tells us all everything we will ever need to know about Vance Breese: pompous, self-absorbed know-it-all who can't back off or apologize even when confronted with his own turd as obvious as this pile of monkey dung here. No sir, he just comes right back at it, re-stating the same nonsense in a few more words.

This newly-added, condescending caveat that "...although I suspect there are some," is a meaningless and empty exercise in snotty disdain, because the fact remains that Vance Breese STILL REFUSES TO ACKNOWLEDGE ANY YAMAHA SUCCESS, INCLUDING EVEN MY OWN YAMAHA CONVERSION FINISHED 2012 AND STILL FLYING TODAY, one which we are all aware by now he has had plenty of first-hand, operational and static, observation and inspection experience with, both at 2013 Bensen Days and 2015 Mentone.
 

Abid

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It appears that Yamaha sled engines have been installed in some gyros for about 13 years or so.
I'm curious about the pros and cons of these installations.
I've read the threads Kevin has provided. I've also read about a few installations that seem to work well.

What appears to be the primary reason they have not become common in the aviation community?
Jim

I know of 4 Yamaha conversion engine outs and 2 near engine outs (overheating). One problem seems to be coolant circuit and water pump giving out regularly.
 

WaspAir

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Swapping out one Lycoming for another one a bit bigger is not cutting edge nor breaking news, nor does it qualify you as a builder, an innovator, or anyone with the proper expertise to seek out and rely on for build and/or conversion advice.

Pat yourself on the back.

As far as this thread topic goes Vance has nothing to offer but stale, self-important opinions, backed up with zero experience.

Opinions are like elbows...

That VB still maintains today this BS that, "I don’t know anyone who has had a trouble free Yamaha sled engine in a gyroplane...", tells us all everything we will ever need to know about Vance Breese: pompous, self-absorbed know-it-all who can't back off or apologize even when confronted with his own turd as obvious as this pile of monkey dung here. No sir, he just comes right back at it, re-stating the same nonsense in a few more words.

This newly-added, condescending caveat that "...although I suspect there are some," is a meaningless and empty exercise in snotty disdain, because the fact remains that Vance Breese STILL REFUSES TO ACKNOWLEDGE ANY YAMAHA SUCCESS, INCLUDING EVEN MY OWN YAMAHA CONVERSION FINISHED 2012 AND STILL FLYING TODAY, one which we are all aware by now he has had plenty of first-hand, operational and static, observation and inspection experience with, both at 2013 Bensen Days and 2015 Mentone.
So you hate Vance. No news there. Hearing about it grows tiresome very, very, quickly. Can we move on?
 

GyroRon

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Name me any engine brand and model that has been put on an experimental and has never had any issues.............

Subaru... They have issues

Mazda... They have issues

VW..... They have issues

Lycoming.... They have issues

Rotax.... They have issues

Viking.... They have issues

What else???

You would be a Freaking Idiot to sit here and say ( Insert your favorite brand here ) engines are bullet proof and will never ever give you any problems.

You would also be a freaking idiot to sit here and say ( insert any of the not favorite brand engines here ) is trash and should be avoided like the plague.

Is it at least somewhat true that your LESS LIKELY to have problems with some engines versus others???? Yes absolutely.

But does that mean that these " Others " are going to be failures and should be avoided???? No not at all.


If it would cost you 10 grand to put together a nice Yamaha engine package, Or you could just buy a new Rotax 912 series engine package for that same 10 grand.... And parts cost was similar.... I am pretty sure most folks would pick the Rotax. Why? Because the Rotax has a well-known history and has proven to be a trustworthy and dependable engine.

The Yamaha has proven to be a trustworthy and dependable engine IN A SNOWMOBILE... And so far it has had a reasonably good record as a aircraft engine but there has been some problems with it. Mostly with the reduction drive systems, but also in the cooling system on some engines.

But the reality is a Rotax 912 series engine will cost you double or triple what a Yamaha engine package will, and some people just want to save some money and are willing to be the test pilot and hope for the best.

Good thing about the yamaha engine situation is more and more people are flying them. First it was Todd ( Racer here on the forum ). Then me, then Jason ( who mounted one on a Kolb ultralight plane ), Then you started seeing more and more people use them but it was mostly gyros. But now a days more and more people are putting them on airplanes. And one very famous airplane pilot, Steve Henry, uses one and is smashing records in the STOL world. As more people use them, it builds on the engines track record, it also helps identify and solve issues.

You will probably never see Yamaha be regarded in the same way as Rotax. OEM's typically like to buy ready to run engine packages, and ones where there are trained mechanics and service centers to maintain and repair them as needed. Rotax has this covered. OEM's do not want to go through the trouble of having to convert engines, At least most don't. And I don't see Yamaha wanting to get into the business of making aircraft engines to market and sell to us... ( and if they did, you can bet your A$$ they wouldn't be much if any cheaper than a Rotax at that point )

There is no reason to argue and fight amongst ourselves here about engines. Facts are Facts...
 

Smack

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So you hate Vance. No news there. Hearing about it grows tiresome very, very, quickly. Can we move on?
Asking people to 'self-censor' grows tiresome very, very quickly.

It also detracts from the thread and flow of information (some good, some bad).
If you don't like it, put Ron on 'ignore' or otherwise start self-censoring...
Thank you.
 

WaspAir

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Asking people to 'self-censor' grows tiresome very, very quickly.

It also detracts from the thread and flow of information (some good, some bad).
If you don't like it, put Ron on 'ignore' or otherwise start self-censoring...
Thank you.

Okay. You and Greg (not Ron) are on my ignore list now. Feel free to ignore me as well if you find I am too disruptive to the flow of any thread.
 
Last edited:

schmoe90

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And I don't see Yamaha wanting to get into the business of making aircraft engines to market and sell to us... ( and if they did, you can bet your A$$ they wouldn't be much if any cheaper than a Rotax at that point )

There were rumours in the 90s that they were looking at using their 2 cylinder 4 stroke engine (as used in the TDM850 motorcycle) as the basis for an aero engine, but that all went quiet - I'm ass-u-meing that was when their lawyers pointed out the liability issues. It's a shame, as a lot of us had high hopes for them.
 

Aerofoam

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Warning, thread drift!

I use a a lot of 2strk. 2-cyl boxer engines in UAV's
The 100cc 10HP one weighs about 9lbs w/exhaust and we have put thousands of hours on these with no issues.
I know for a fact that the 2 companies that make the ones we use have hesitated to produce larger (400cc) versions
because they are afraid of the ultralight community using them and causing liability issues.
it is sad that a company can be sued for someone using their product outside of it's intended use.
A friend of mine is one of the manufacturers and he may put one into production.
I can tell you that it would probably be in the 40 to 45lb. range and produce at least 55HP.
I have read about a couple of BMW 1000cc and 1100cc conversions.
This seems like it could be a solid AC use, especially with a turbo charger.
Those engines are very robust and basically originated from aircraft engines in the first place.
 

WaspAir

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I have read about a couple of BMW 1000cc and 1100cc conversions.
This seems like it could be a solid AC use, especially with a turbo charger.
Those engines are very robust and basically originated from aircraft engines in the first place.
I have some doubts about that. BMW has been building boxer motorcycle engines since about 1920 (M2B15 ?). In WWI, they were making big inline 6s, watercooled, for Fokkers. I don't see an aircraft origin for the bike boxers. Do you have info on that pedigree that I might have missed?
 

Aerofoam

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I saw a pic. of an early air cooled boxer that was essentially their version of a scaled down radial, I don't know if it was before, or after their affiliation with Pratt/Whitney and assumed it evolved from there, could be completely off base, but it doesn't negate the fact they started as an aircraft engine company and their boxers are are very stout engines. They are a bit heavy though..
 

Vance

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I saw a pic. of an early air cooled boxer that was essentially their version of a scaled down radial, I don't know if it was before, or after their affiliation with Pratt/Whitney and assumed it evolved from there, could be completely off base, but it doesn't negate the fact they started as an aircraft engine company and their boxers are are very stout engines. They are a bit heavy though..
At the end of World War I, the Treaty of Versailles demanded that BMW cease production of aircraft engines. BMW began making small industrial engines and in 1923 Max Fritz designed the first BMW motorcycle; the R32.

When considering a motorcycle engine for conversion to gyroplane use I feel it is important to recognize that most of a motorcycle engine’s life is spent making less than 20 horsepower while a gyroplane engine will spend most of its life making more than 50 horsepower.

In my opinion more smaller cylinders will be easier on a propeller speed reduction unit than two large ones.
 

Aerofoam

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At the end of World War I, the Treaty of Versailles demanded that BMW cease production of aircraft engines. BMW began making small industrial engines and in 1923 Max Fritz designed the first BMW motorcycle; the R32.

When considering a motorcycle engine for conversion to gyroplane use I feel it is important to recognize that most of a motorcycle engine’s life is spent making less than 20 horsepower while a gyroplane engine will spend most of its life making more than 50 horsepower.

In my opinion more smaller cylinders will be easier on a propeller speed reduction unit than two large ones.

In the case of the BMW boxers, they are fairly over built and have incredible lifespans putting up with more inconsistent and harder loading experienced by an engine hard coupled to uneven surfaces while accelerating and experiencing more momentary load forces than an aircraft engine pushing a prop.
Also remember that they used shaft drives, so the engine had to take more of a direct coupling than a chain drive.
Your reduction comment is even more applicable though, because the 2 cylinder boxer is firing in unison as a single cylinder, so the power pulses will be very apparent.
I think you would have to use a belt, it would kill a light weight gear drive quickly....
The other big consideration would be cooling. I don't think the BMW boxer would have an issue operating at 75% as long as you could keep it within operating temps.
As you stated, it wasn't designed for sustained high output and this may be the weakest link.
I have seen ultralight conversions from 600 and 900 series, but they were probably running less than 50hp.
I would still like to play with one!
 

Vance

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Your reduction comment is even more applicable though, because the 2 cylinder boxer is firing in unison as a single cylinder, so the power pulses will be very apparent.
I think you would have to use a belt, it would kill a light weight gear drive quickly....
The last BMW boxer I worked on fired one cylinder at a time.
While one cylinder reaches top on the compression stroke the other reaches top on the exhaust stroke.
 

martin-av8r

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To reply about the other thread post on turbo lag

with today tech available and good software and hardware choice for best engine calibration mapping

if you want you can have a turbo system with no lag , like this snowmobile engine

it feel like a big naturally aspirated engine


 

martin-av8r

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Hey Greg you have a nytro 3 cylinder to try your idea on the cooling system

it can be interesting to know what is the most accumulated flying hours on a yam 3 cylinder

the 973cc and the 1049cc i think it is the tango that can have the most hours on a 3 cylinder yam

if Pavel Vagner want to tell us about it , i remember a bit in the past he or another guy

talk about a tango mulet test bed for blade test and other flying stuff that accumulate a max number of hours ?

or Tom
 

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The last BMW boxer I worked on fired one cylinder at a time.
While one cylinder reaches top on the compression stroke the other reaches top on the exhaust stroke.

Which engine was that?
I had an RS/LS 600, I am fairly sure it was unison, it was a real thumper, I didn't like it, but it had low end torque.
I preferred smooth inline Japanese 4 cylinder engines that sound like formula 1 cars......
Good thing I gave it up.....
 

Vance

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Which engine was that?
I had an RS/LS 600, I am fairly sure it was unison, it was a real thumper, I didn't like it, but it had low end torque.
I preferred smooth inline Japanese 4 cylinder engines that sound like formula 1 cars......
Good thing I gave it up.....
R 1200RT as I recall a 2016. I have not seen a BMW twin that fires both cylinders at the same time.
 

schmoe90

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I think you would have to use a belt, it would kill a light weight gear drive quickly....

A friend modified and installed a Rotax C drive to an R1100 (or maybe it was an 1150) engine ages ago. He tested it a fair amount planning to replace the 912 on his weight shift trike, but sold it to somebody to use on a powered parachute - no idea what ever happened to that.
 

WaspAir

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Which engine was that?
I had an RS/LS 600, I am fairly sure it was unison, it was a real thumper, I didn't like it, but it had low end torque.
It is extremely common for motorcycle engines to have the crank set up as Vance describes, whether boxer or not. My very British Norton parallel twin has the pistons moving in unison but out of phase in the 4 cycle pattern so that only one cylinder fires at a time. On the down stroke, one is intaking while the other is on the power stroke; on the upstroke, one is exhausting while the other is compressing.
 
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