RunRyder RC
 31  Topic Subscribe
WATCH
 7 pages [ <<    <     4      5     ( 6 )     7     NEXT    >> ] 15707 views POST REPLY
01-11-2011 03:14 PM  7 years agoPost 101
wjvail

rrKey Veteran

Meridian, Mississippi

My Posts: All  Forum  Topic

I once had a friend I worked with come in very excited about buying a new Harley motorcycle. He had just learned that HD was going to make a bigger engine by simply boring out an existing engine and installing a larger piston. Same engine but much larger jugs. The simplicity of this amazed him and he had to have one. Just a bigger piston. "How beautiful is that!"

Since I had a moment I thought I'd razz him a little. I asked: Do you think they engineered larger valves for this larger engine? You know, with a larger bore you'll have a larger head and more room for larger valves. Do you think they redesigned a larger crank for these larger/heavier pistons? Do you think they engineered larger carbs to feed the greater displacement? Are the rods, crank journals, and wrist-pin now optimized for the greater displacement? If it's the same jug with a bigger hole, isn't that going to leave the same cooling fin area for more fire? Harley's are shakers in the best of times but with a larger piston won't it shake more? Is everything on the bike ready for that?

In the end he began to see he wasn't going to end up with an improved, larger displacement engine but instead a cobbled together, half engineered, larger displacement old engine... and the beauty of it began to fade.

"Well, Nothing bad can happen now."

PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2011 03:34 PM  7 years agoPost 102
DS 8717

rrProfessor

Here wishing i was somewhere else

My Posts: All  Forum  Topic

lotta if's there,larger engines dont necessarily need bigger valves. There are 3 or 4 different heads with different port size and valves for the big block chevy engines.it depens on how you want the power curve as to what heads you use with your set up. YS doesnt cobble together engines,they have been building engines for over 30 years. They have some pretty impressive 4 strokes out now with fuel injection in the 160 size that were made from the 120 size case......
YS knows what they are doing,some of the same people that down play the new engine will end up buying one when its over.....

YOU ONLY LIVE ONCE..IF YOU LIVE IT RIGHT THATS ALL YOU NEED

PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2011 03:43 PM  7 years agoPost 103
Richardmid1

rrProfessor

Leeds, England

My Posts: All  Forum  Topic

He has a point about vibration though, vibration kills helis!

60% of the time, it works every time!

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
01-11-2011 03:57 PM  7 years agoPost 104
REGULATER

rrApprentice

Bakersfeild, CA

My Posts: All  Forum  Topic

I have seen this motor with my own eyes and watched Tim Jones testing the 120 I would have to say it vibrates less than the YS 3DS. Its still in the testing stages. But did not see any vibrations! The motor looks very promising.

PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2011 05:30 PM  7 years agoPost 105
wjvail

rrKey Veteran

Meridian, Mississippi

My Posts: All  Forum  Topic

YS doesnt cobble together engines,they have been building engines for over 30 years.
A couple of things... I like Yamada products. You might not garner that from my posts but don't dislike YS. I own over 300 engines and at least 7 YS's. Every time OS pisses me off enough, I buy another YS. I do like YS.

Second, I've been modeling for 40 years and YS WILL cobble and this 1.20 engine may a good example. It is a YS .61ST1 upgraded to an .80 then .91 (several iterations) and now 1.20. Either the .61 or the 1.20 was poorly designed but you can't have one case optimized for engines 100% different in displacement. One or both engines will be badly compromised. Since you mentioned big block Chevy's, would you have an opinion of a Chev 427 released from the factory as an 854CID?

Have you ever asked what the two dimples are just under the carb are for? Have you wondered what the polished spot is on the side of the case does? See attached pictures for a hint...

"Well, Nothing bad can happen now."

PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2011 05:35 PM  7 years agoPost 106
DS 8717

rrProfessor

Here wishing i was somewhere else

My Posts: All  Forum  Topic

I have one of those YS 60 engines myself,and i have been modeling for 55 years....I have yet to see a cobbled YS engine that they sell to the public,prototype engines might be cobbled for development but they make the final version right.

YOU ONLY LIVE ONCE..IF YOU LIVE IT RIGHT THATS ALL YOU NEED

PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2011 06:09 PM  7 years agoPost 107
wjvail

rrKey Veteran

Meridian, Mississippi

My Posts: All  Forum  Topic

In the first photo is a 1970's vintage OS .61F-SR (airplane engine), a 1980's vintage OS .61SFN-H, a 1990's OS .91 SX-H, a YS .91 and a GMS 1.20(airplane). The second photo is of the YS .91 and the GMS 1.20.

If you look carefully, the bolt pattern for the OS .61SFNH from my earliest heli days is the same for the modern OS and YS .90. The bolt pattern of a .61 now defines the case size of a modern 90/1.20 heli engine. Since the case size is now roughly fixed to the size of a .60 case, many other items of the engine must be compromised to accommodate the spacing between the mounting beams.

The most obvious limitation is, can you optimize the rear bearing size for an engine that is now grown 100% in displacement? The 2nd photo is included not because of any real love of GMS but only to suggest what a 1.20 might look like if not restricted to the mounting pattern of a 1980s .61. The engine on the left is a .61 up-sized to a .91 soon to be a 1.20 and the engine on the right, is a 1.20. You can assume the rear bearing is roughly the size of the back-plate.

With the size of the rear bearing now limited, can you put the crank in the engine you'd like? If the main dia of the crank now becomes fixed by the rear bearing, can you get a large enough bore through the crank to feed a 1.20?

If you are now using a .61 case for a 1.20 engine, are you able to optimize the design/size/area/flow volume of the transfer and boost ports in a case that was designed for an engine now twice its original design displacement?

The .61ST1 case was prone to cracking just behind the carb when stretched to an .80. That was fixed by moving the carb slightly and hasn't been as be a problem in the .90 but it does suggest we are approaching the structural limit on the .60 case.

The point of my posting is not to bash Yamada. As I said, I like YS. If you take anything away from my ranting it's that I think we should expect more. For $400ish USDs, I think we should demand more than a rehashed, stretched, and yes cobbled together .61ST1. I bought the 1.20 pictured from Randy at MECO for $79.00. No it is NOT a YS but for $400 I think we should expect a truly new engine from YS more frequently than every 15 years.

"Well, Nothing bad can happen now."

PM  EMAIL  GALLERY  Attn:RR  Quote
01-11-2011 09:48 PM  7 years agoPost 108
blade3d

rrElite Veteran

New Jersey USA

My Posts: All  Forum  Topic

Does this leaves OS in the dust

Blade3d

PM  EMAIL  GALLERY  Attn:RR  Quote
01-12-2011 02:55 AM  7 years agoPost 109
Inspector Fuzz

rrKey Veteran

NLA

My Posts: All  Forum  Topic

@wjvail
Great post and pictures.

You have shown exactly what I have been talking about. The case on that GMS 1.20 is about what we ought to see on that new 1.20 or even the .91's.

There is something else that no one has brought up yet. The cast part of the cylinders on these motors keeps getting thinner and thinner.

The "heatsink" action of the metal is an importan part of the cooling and the upper part of the case on these motors are thin and do not transfer heat as well as the old .61's did.

Whoever talked about boring out a big block chevy 454 to 900+ci made a good argument, too.

PM  EMAIL  Attn:RR  Quote
01-12-2011 03:57 AM  7 years agoPost 110
alfred

rrVeteran

Australia, New South Wales, Mid North Coast

My Posts: All  Forum  Topic

The reality is that a 91 with muffler now costs more then a 50size heli kit.
If you look at how many CF parts, CNC machined aluminum, stainless and hardened steel, injection molded parts..etc are in a kit, then our engines today represent poor value.

Both the 50 and 91 size engines are way too expensive, considering that they don't even come with a muffler.

I understand that we are a highly specialized niche market and as such can not be compared easily to other products, but surely we can expect better then regurgitated parts with small mods.

How about the engine manufacturers pre-run the engines and give us needle settings "specifically" for the given engine you buy, with what muffler and fuel they pre-ran it.
At least then I could see justifications for the cost due to labour.

The above comments are general and not specific to YS.

Here are some specific comments:

I have 4 YS engines.
2 run beautiful and two run like a dog.

My now retired YS61ST-2 used to flame out for no given reason.
I did more forced autorotations with it then I care to remember.
Just about when it was clapped out and after about the fifth pull apart the carby and flushing it out, it finally flushed out the finest piece of curled shaving.
After that, it finally ran consistent, but by that time, the engine was close to worn out.

Then the YS50, purchased what?...at least 5+ years later, is the same crap. It doesn't flame out, but seems to vary it's temperature like a sick puppy. It has been monitored with an eagle tree and tuned from the readouts, but the spikes will happen even in hover and the carb has been cleaned out multiple times and every seal/diaphragm etc has been replaced in the carby.
I finally mounted a carbsmart to it.
It now is finally settling down and my next move will be to replace the ring.
Hopefully I will then finally end up with a more reliable engine.

But my YS80 and 91ST run like sawing machines.
Surely for that kind of money and today's machining and molding capabilities, we can expect better consistency between engines then we are getting now.

Compare this to a Super Tiger 51 aero engine for my son's plane.
Less then a third of the cost, includes the muffler.
10% instead of 30% Nitro and after 5 tanks makes not just great power but is 100% consistent and reliable.

It's a bit of a joke.

PM  EMAIL  Attn:RR  Quote
01-12-2011 10:43 AM  7 years agoPost 111
HeliPhil

rrApprentice

Brentwood, Essex, UK

My Posts: All  Forum  Topic

the real compromise is that the engine mounting points in the heli havn't changed - surely it can't be that hard to make them bigger to accomodate larger engines ( and the 60's and 90's as well)

PM  EMAIL  HOMEPAGE  GALLERY  Attn:RR  Quote
01-12-2011 01:29 PM  7 years agoPost 112
Dr.Ben

rrMaster

Richmond, VA, USA

My Posts: All  Forum  Topic

With many of the current frame designs which are wider for increased rigidity, there is enough room for a wider case. It just takes the leap of faith (and maybe a discussion with a heli mfg or two) to have the companies evolve the nitro chassis to accept what the case size really needs to be. Another likely unspoken concern is that when a larger case, bearings, etc are used, the engine cost will likely break the $500 price point. Some segments of the market begin to get a little weak in the knees about buying a $500 motor and what will easily be a $200+ muffler.

Ben Minor

Team Futaba Team Kontronik USA

PM  EMAIL  GALLERY  Attn:RR  Quote
01-12-2011 02:05 PM  7 years agoPost 113
DS 8717

rrProfessor

Here wishing i was somewhere else

My Posts: All  Forum  Topic

Bearing changes every now and then is worth the smaller lighter weight this design offers. And as Ben stated the cost would probably be better with the compact design vs a whole new larger based case.
So far the actual testing by p[ilots have shown the engine to be smooth and very little changes to the airframe are needed with thi design.

YOU ONLY LIVE ONCE..IF YOU LIVE IT RIGHT THATS ALL YOU NEED

PM  EMAIL  GALLERY  Attn:RR  Quote
01-12-2011 02:09 PM  7 years agoPost 114
PC12DRVR

rrKey Veteran

USA

My Posts: All  Forum  Topic

Whens this beast going to be available? Ill try one out!

PM  EMAIL  GALLERY  Attn:RR  Quote
01-12-2011 03:01 PM  7 years agoPost 115
Jim Woodward

rrApprentice

Boca Raton, FL

My Posts: All  Forum  Topic

REGULATER - Thanks for the positive observation. Please keep the reports coming!! Jim

Team Futaba

PM  EMAIL  GALLERY  Attn:RR  Quote
01-12-2011 08:03 PM  7 years agoPost 116
EricBrandenburg

rrApprentice

Milwaukee,WI

My Posts: All  Forum  Topic

I can see one of these in my future. Who cares if you get 5 flights out of a gallon, since when is flying a 90 class heli budget oriented? It'll be very cool to see this motor close the gap between the electric hot rods that have become so commonplace.

PM  EMAIL  GALLERY  Attn:RR  Quote
01-13-2011 08:00 PM  7 years agoPost 117
Jim Woodward

rrApprentice

Boca Raton, FL

My Posts: All  Forum  Topic

Guys - after some careful thought I wanted to post a comparison about what can be done with crankcases by YS (info not usually posted on this website).

In the 4-Cycle world (F3A, top placings at WC forever), YS has gone from a 120 (18-20 years ago) to a 175 (today) and used the same lower crankcase, and same rear bearing. The 170's I have make HUGE power and swing 19-20" props, where as the 120 was swinging 14-15" props. Many people that run the 4-cycles state that it has never been easier to handle, start, and get great performance from the engine. This is an example of the motors getting more powerful, more dependable, swinging heavier loads and mass, and useing the same lower bearing and crankcase. In an F3A installation, the engine has about 1.25 x 2.0" window of air infront of the cylinder, but is otherwise tucked in a large belly pan. Cooling is no where near as efficient as what has been developed for heli's. Worsening the situation, the engines are soft mounted and isolated by a rubber nose ring (there is no large metal engine mount to wick away heat as compared to the heli install).

Also in this time, the "YS 170 CDI" motor came out and users went from CP 30% Heli fuel to running special low-oil contents of 12% or less oil in the fuel. The CDI box allowed the motor to be ran leaner such that a 25% fuel savings was seen. The leaner mixture, plus the lower oil, DEFINATELY RAISED the potential for heat issues and component life. I've ran the CDI units but returned to Glow Plug use, believeing that on hot humid days, the motor just liked more fuel flowing through it. Other people just keep truck'in along on the CDI unit. No crankcase failures, no rear bearings going bad.

4-Cycles run hotter than 2-Cycles, but at less RPM's. 2-Cycles are spinning higher, fire once a rotation, but are setup with direct fan cooling where as the 4-cycles are tucked away inside belly pans with a very little window of cooling allowed. The 2-cycle is gets effectively, twice the fuel and oil per revolution versus a 4-Cycle.

It will be very interesting to see if the recent 4-cycle developments of the 170, CDI, and now 175, have given anything back to the 2-Cycle development.

Also, there is a reported "gasoline" version of the 170 CDI - which would run even hotter and have (comparetively) even less metal to wick away heat compared to true gas engines, being tested.

Therefore there are examples with YS effectively being able to design improvements within its crankcases and rear bearings

Food for thought...
Thanks,
Jim W.

Team Futaba

PM  EMAIL  GALLERY  Attn:RR  Quote
01-13-2011 08:27 PM  7 years agoPost 118
knightofcarnage

rrElite Veteran

chicago

My Posts: All  Forum  Topic

That engine look very interesting to me.
http://f3a.sakura.ne.jp/radiocontro...obbyShow01.html

PM  EMAIL  GALLERY  Attn:RR  Quote
01-14-2011 01:32 AM  7 years agoPost 119
Dr.Ben

rrMaster

Richmond, VA, USA

My Posts: All  Forum  Topic

Jim,

The data are interesting, but I'm not so sure you can compare an F3A 4C engine turning at 1/2 half or less of the rpm of a heli engine (assume 16K on an 8.2 ratio with some guys turning as much as 2000 rpm). For a given 8.5 minute flight with no autos, that's over 139,000 revolutions. The motor never gets a break or a breather in a helicopter.

Ben

Team Futaba Team Kontronik USA

PM  EMAIL  GALLERY  Attn:RR  Quote
01-14-2011 02:16 AM  7 years agoPost 120
slickporsche

rrVeteran

American/Philippines

My Posts: All  Forum  Topic

On the pipe
I know you can at some point run a true tuned pipe, and get more power on 10%. It is what I was doing 20 years ago, and it worked great. Then the 30% became available and I tried it. Reason it is better???? Because you can get the power of a pipe on a MUFFLer and it is not as tricky to tune. So many guys have no tuning ability so the 30% and a dummy proof muffler did the trick. I followed the trend, and then got tired of it. It would seem if you want 3D performance that a tuned pipe would be the ticket as it really performs at top end.

PM  EMAIL  GALLERY  Attn:RR  Quote
WATCH
 7 pages [ <<    <     4      5     ( 6 )     7     NEXT    >> ] 15707 views POST REPLY
 Print TOPIC  Make Suggestion 

 31  Topic Subscribe

Friday, April 20 - 9:50 am - Copyright © 2000-2018 RunRyder   EMAILEnable Cookies

Login Here
 New Subscriptions 
 Buddies Online