vintageflyer

My Feedback: (1)

Can someone tell me what's the difference in these engines?

ok I can assume the LS is long stroke, but what does AR, R,ST all stand for?

DM

Atlanta 60

My Feedback: (18)

LS= Long Stroke

R= Rear Exhaust

AR= Short for: arrrrrr... Get out of my Way
(Actually..The YS 61R AR was a Hopped up version of the YS 61R LS....Kinda like the OS RF-P and the RF-P Hanno Special)

ST= I'm not exactly sure what that stands for...But the ST-2 engine is a current Hecolopter engine (I think is still being manufactured??)...It's not a Pattern Aircraft engine...




This may help?? I posted this a week or so ago in another forum in response to a question:

Ha...Just so happens I have a couple of basket cases taken apart so you may be able to see some of the differences a bit easier...(Photos Below)...Now I'm not an expert on these...I'm still studying and learning as I go with these engines...I think there are allot of guys who flew these in the 90's who may have some better info than I...I'm kinda going off what I have learned thusfar and don't have allot of past experience to speak from...So if I get something wrong...You Old School Guys feel free to correct me!!

In the "Parts" photos...The AR stuff is on the left...The Std LS stuff is on the right...

Pic 1: You see some pretty noticeable design difference in the AR's Piston & Liner vs the std LS...The AR's piston liner is Aluminum (AAC) and is allot lighter than the std LS which is an ABC piston/liner...

Pic 2: If you look very closely you will notice there are some differences in the crank...The AR crank has a couple of shims placed aft of the rear bearing land...Those shims ride inside a brass collar seen in the next photo...Apparently this was designed to aid in fuel delivery...The "Intake Porting" is different also...I believe timing is a little different too...You will also notice in the AR case has a hole just below carburetor which is for oiling the rear bearing for storage...And the AR has a machined head vs the LS's cast aluminum head...

Pic 3: A look at the "Brass Sleeve" which is mentioned above...

Pic 4 thru 6: You'll notice the engines look very similar externally...The difference in the heads and oil plug are about the only noticeable external differences between them...

The performance difference between the LS and the AR is similar to the differences between the standard OS RF-P and the OS RF-P "Hanno Special"...

Designed to run Tuned Pipes (Hatori 650)...

The LS makes it's power while turning a little higher RPM...About 11,500 on a 12x8 is what I have read the guys were running "Back in the Day"...A 12x10 is about tops on the std LS...Mine are turning 10,800 on a 12x10 on my test stand...Very similar to the OS RF-P...

The AR is kinda like the Hanno...It is designed to turn less RPM's and will swing a bigger prop...I'm still learning all this too...But I'm planning on running the AR on a 12x12 or a 12.5x12 and shooting for just under 10k RPM's...My Hanno's are turning 10,300 on a 12x12 APC prop on the test stand...I expect the AR will be right there too...So I'd like to tweek them closer to 9500 RPM...Which is apparently the "sweet spot"...

So sorry if that is too much information...he he...The rest I have yet to learn myself...But it sure is fun!!



Added Photo: I had to add another shot of my "Other Favorite Shelve"...Now..Just to get them out of the boxes and on to Airplanes!!

Since I wrote this I've at least run one of the AR's...That's a step in the right direction!! Baby steps ya know..

Chuck

vintageflyer

My Feedback: (1)

Chuck, I think your collection of engines are worth more than the car I drive!!
And yet again, Thanks for your help. That was exactly what I was hoping to find out, and then some. I am in the process of getting an AR arrrr version with a pipe(little banged up) froma guy here on RCU. I have a side exhaust YS61, but I never ran it. I picked it up used (such a good deal, Had to have it). Now I think it sould be time to get it out for some duty.
I don't have a tach anymore. Which one would you recomend?

DM

dhal22

Geeze, no wonder YS 61 AR's are in short supply. Someone is hoarding them!![sm=teeth_smile.gif] Outstanding!! Must be great to enter your hobby room and see that stash waiting for you.

vintageflyer

My Feedback: (1)

He also has 3 Hanno on his bench. Not to mention what he has in his planes!
I could help you out and "test" your engines for you in my plane. Really, I wouldn't mind .

DM

Atlanta 60

My Feedback: (18)

My engine collection IS worth more than my car...For Real...It's Sad...

But you gotta have your priority's in order...Right...OK..So mine are a little skewed..

pacoflyer

My Feedback: (23)

Maybe one of you gentlemen can help me with this. I have a 61 AR that makes great power but will not idle any more. The diaphram is fine and internally the carb is clean. As soon as I throttle down, the engine dies within 15 seconds or so. The plug is fine [OS A3.A8] and I'm using Powermaster YS fuel.
Any thoughts ?
thanks

airbusdrvr

Check you pressure line to the tank. On one of my first installs of the YS 61 I put one of those spring clamps around the nipples of the fuel tank. I did this thinking it would help retain the fuel lines on the tank as this was a "pressurized" system. But after a few flights, the clamp cut into the fuel line allowing the pressure(and a little fuel) to leak. Just a possibility.

airbusdrvr

Atlanta 60, your stack makes my three boxes look rather puny.

Atlanta 60

My Feedback: (18)

After you confirm the tank pressure is good as airbusdrvr suggests... (all the fundamental stuff like the regulator adjustment, check valve ect is all OK too)

How long has it been since you put bearings in it?? How old is the engine?? lots of flights??

The YS factory bearings are pretty crappy in my opinion...If all else is good then I'd suggest a set of "Good Quality" Stainless or Ceramic/Stainless Bearings, Gasket Set, O-Rings and while you at it a new Diaphragm, Plunger and Spring...

The kicker for me is you statement "will not idle any more"...That leads me to believe it use to idle fine...If that is the case and all the fundamental stuff is good....Should be Bearings..

http://www.rc-bearings.com/
http://www.bocabearings.com/

Just my Opinion...

Chuck

pacoflyer

My Feedback: (23)

Thanx guys for your quick reply. After the engine has run and the fuel dot is uncorked I get a pretty good pressure release but I'll go ahead and check the plumbing again. The brass pump adjust screw was flush with the case and screwing it in or out had no afect on the idle. The diaphram looked pretty good too. There is probably 15 flights on it since the bearings were replaced so I hope that's not it.
Thanx again,
paul