rodders

Hello all,
I have been keeping my eye out for a nice Webra /Hanno/YS 60 to go in my Prettner Calypso.

How would a modern engine such as the OS 55 compare in terms of power?
Has anyone done some new to old engine comparrisons.
Regards,
Rodders

airbusdrvr

You might post on the Tachometer Readings forum, http://www.rcuniverse.com/forum/forumid_173/tt.htm

ChiefK

I just picked up a NIB Webra Speed .61 "Champion" with an installed Perry pump on the auction site. I also have an O.S. .55AX. The O.S. is pretty strong on an APC 12X6, maybe close to the power of my old Webra Blackhead (but lighter). I expect the new Webra Speed will be considerably more powerful than the O.S. It should turn a 12x7 as fast or faster. Probably won't run the Webra until I finish my "Deception" project in a month or so. I had to order a new engine mount because the Perry pump will require that I mount the new Webra a little further from the firewall than my older non-pumped Webra Speed .61. So I can't make a real comparison until then.

ChiefK

Atlanta 60

My Feedback: (18)

Very good question!!

I sometimes wonder how the engine manufacturers come up with the "horsepower" ratings they advertise...There doesn't seem to be much consistency from what I can tell and boiles down to an advertising gimmick in my mind...

I see Dub Jett reference the power of his engines buy what prop it will swing at what RPM...This seems logical to me...Obviously there are going to be slight differences in propeller performance but it seems a much more reliable reference than the ambiguous horsepower ratings listed in an ad...

Someone around here has a "horsepower calculator" of some sort which may be a chart or formula...I forget who had it but I have seen that person "correct" some advertised HP ratings using this formula..I'm not familiar with whatever program or formula it is...

I think when your dealing with a tuned pipe sort of engine there is a little bit of gray area there too because it's dependent on prop & pipe selection, fuel, ambient conditions and how the individual engine is tuned ect...

I have an old OS Horsepower rating chart here gut I'm not sure how they arrived at these numbers??
http://origin-images.rcuniverse.com/...21/Wu59711.pdf

I have never owned an OS 55AX but hear it's a pretty strong running engine...Tower lists a 12x8 propeller in the specifications section in their ad...It may haul the Calypso around just as well as an old school engine?? I just happen to be partial to the old school stuff because it looks neat...

One pretty big dis-advantage to the old engines is parts availability...I mean bearings are kewl cause you can get them...But depending on what engine your talking about can you get the gaskets so you can open the case to change the bearings out?? I hate to say t but I think that is a consideration...

The OS long stroke engines pretty much have a re-usable backplate gasket so your probably gonna be OK on those...But good luck on a YS-60 short stroke engine because even if it's brand new your gonna tear the paper gaskets up if you disassemble it...They are no longer available unless you find someone selling a set on "the bay" or something like that...

It's kinda a tough deal because I like the old engines soo much...I have bought and gone through several and I'll have a tough time parting with any of them...Allot of mine were bought used as "fixer-uppers"...However if the truth be told I probably have twice the cost in each one of my engines than what a new modern engine would cost you...In my case I knew that going in and for me it was a labor of love more than anything...It's not really what I'd call practical though...

OK...So again I ramble...Just my .02...

Chuck

flywilly

My Feedback: (121)

If you want ballistic and a new OS then use a 75AX. Great performance with the stock muffler. The 55AX is a terrific engine for SPA sized airplanes. OS has engineered their AX line for more torque oriented performance (larger props, lower rpms).
-Will

energyman

My Feedback: (2)

In response to the question regarding the Webra Speed 61, I picked one up new in the early to mid 90's. It is an ABC version with the TN carburetor and I have been runnng it with a Mac pipe and uncut header with an APC 12x8 at 12,000 RPM, and with the same pipe setting an APC pattern 12x10 at 11,050 RPM, both with Powermaster 15% fuel. It pulls an 8 pound airplane very well with good vertical. With a Webra muffler, the APC 12x8 turned 11,100 RPM and the APC 12x10 turned 9,600 with 5%Powermaster.

The ABC version turns an APC 11x7 at 12,500 RPM with the muffler and 5% Powermaster. I have a older Webra Speed 61 that is a ringed engine and it turns the APC 11x7 at 12,300 RPM with the muffler and 5% Powermaster. Hope this helps. Good luck.

Energyman

chrisseawright

This is a question I have asked in one of the threads I started and this is what I have learned from everyone on this subject. As attlanta 60 said using the older engines on a period type pattern plane ads tons of cool points and if you can find one in good condition the power is hard to match but its also hard to find parts and if your not good at building engines it wouldnt matter anyway. As far as the new engines the one that keeps comming up is JET Engineering so I called them and they recomended an engine for me the good thing with this is I can send it back and let them rebuild it for me. As far as ths 55 ax I have not run one of these engines but I can tell you on my curare my old worn out rossi had more power than a new OS 61 fx. Also as Attlanta 60 said the HP ratings out there are crazy for example my new OS 61fx paper work claims 1.9hp were my older OS 61RF Abc only claims 1.8hp but when but on the same plane using the same prop and fuel thr 61RF is much faster my tach broke so I cant give you the numbers but the plane in the air is clearly faster. So long story short and just like everyone else has said dont fall for the new exagerated HP numbers.

rodders

Thanks everone,
I am also very dubious about some of the HP claims. I understand what you are saying about the YS being potentially difficult to find spares for although there is the odd NIB one to be found.
I keep coming back to the Webra, although I like the idea of a Hanno Special, I dont think it is really suited to the Calypso as it rear exhaust.

Out of intrest was the Calypso airframe designed for the lower RPM, more torque engine period, rather than the all out screaming engines? Do I need to look for a Webra 61 long stroke?

Rodders

NM2K

My Feedback: (14)

The OS .55AX and the Enya .61CX are great forty type engines, but they aren't an old pattern sixty. Not even close. Yes, I have the old pattern engines and the new small case .55 - .61 engines that I mentioned. The latter are works of art and are super useful additions to the engine stable, but a YS or Rossi 10cc pattern engine they simply aren't.

Now, if one were to go bananas making the old classic pattern model extremely light, maybe then the new generation of small case sixties would be perfect.

OS equipped the .55 AX with LOTS of cooling fin area. This permits this petite engine to swing large lumber without overheating. This does not mean that this engine can develop a lot of horsepower with such large lumber (props).


Ed Cregger

Atlanta 60

My Feedback: (18)

My Modeltech Calypso will work very well with a rear exhaust engine...I'm going to use either a OS RF or a YS LS with the engine mounted inverted and the pipe running down the belly...I did have to notch out a little at the bottom of the firewall to get some clearance for the header but not really a big deal at all...

I personally don't like the side exhaust engine mounted on a 45 to get the pipe to run down the belly...I realize that is the "scale" approach and how Hanno apparently had his plane set-up but it's just not my personal favorite option...

Mine won't be very scale anyhow as I filled in the retracts and changed to a fixed gear set-up... [X(]

Just my .02..

Chuck

doxilia

My Feedback: (3)

OS and YS 60's are fairly easy to come by. I would wait for one of these to power your Calypso.

David.

rodders

Atlanta 60,
I agree that it would be best to have the engine straight inverted, I would like to see the finished models
What is the current price of a replacement liner and piston for a Hanno special? I looked at the thread and could not find a price.
Regards,
Rodders

doxilia

My Feedback: (3)

Rodders,

as the Mastercard ad says... priceless - they are no longer in production so it's a matter of someone having one that they do not need, or... the auction site. Bryan (Roguedog) might have some info on the possibility of using a regular RF-P liner/piston on the Hanno. I think it's doable.

I definitely like Chuck's approach on the Calypso. Speaking of which Chuck, what material did you use for the header floor? That looks great! Some kind of lexan from the hardware store? It must bend easily. I need to do something similar on a Mystic for which I decided to mount a SE engine inverted as I don't like the 45 approach either. A custom swan neck header will be required (see pic - it's not the Mystic by the way but same configuration).

One more question Chuck, who makes that soft mount? It's not a Sullivan.

David.

Atlanta 60

My Feedback: (18)

The material I used for the pipe tunnel is some Epoxy/Kevlar sheet I made up...The kit originally came with some fiberglass stock for you to use but mine was so old it was hard as a rock and un-useable...The Kevlar looks much kewler anyway... [8D]

Well heck I was thinkin' the engine mount was a Sullivan but your right it's not...I have a nip Sullivan Flex-Mount sitting on the shelve but the two don't match...I'm not sure who's mount it is?? There is no name or anything stamped on the plate (I threw the package away 20+ years ago...)...Oh well I'm not sure...

doxilia

My Feedback: (3)

Chuck,

No worries about the mount - it looks solid though.

What's entailed in making the Kevlar/epoxy? Where should I buy the stuff? I need to make something that will bend to a 3/4" radius. Picture is of the fuse front tank area where the header will pass (sorry about the poor quality - camera's on the blink). I would continue with the same material in the wing belly for the pipe. Wider radius here.

Is it considerably better than say using glassed 1/64" ply?

David.

Atlanta 60

My Feedback: (18)

Nah plywood would be easier...It would be kinda expensive to buy the stuff and there is not any real "benefit" (unless your plane is shot at and happens to get hit with some small arms fire in the pipe tunnel area...he he)...I just had the stuff laying around and I was trying some kevlar wheel pants so I made a sheet up for this too...

Kevlar is sorta hard to deal with trimming or sanding as the edge fuzzes up rather than sands away smooth like fiberglass or carbon fiber does...I learned a trick though which is to lightly soak the rough cut edge with thin CA which made it possible to get a decent smooth sanded edge...Kevlar is just a tough material and is known for not cutting or sanding well...The lightweight cloth I used is not hard to cut as much as it is to sand...Thicker Kevlar is a real pain to deal with all the way around...

Just thought of something..I'm gonna shoot you a P.M.

Chuck

edit: Where to buy:

I used Style 120 Kevlar (1.8oz) from Aircraft Spruce which is currently $21.75yd
http://www.aircraftspruce.com/catalo...s/bikevlar.php

I used PTM&W Aeropoxy PR2032 resin with the PH3660 hardener which is $41.80 per qt kit (resin & hardener)
http://www.aircraftspruce.com/catalo...s/aeropoxy.php

I know from prior experience PTM&W Aeropoxy will wet out aramid fibers (Kevlar)....Some resin systems won't...Aeropoxy is a mil spec structural resin so I like and use it allot...I'm eventually going to play around with MGS resin system on some Kevlar/Carbon Hybrid material that I have and see how that goes...I'll probably try the MGS with 100% Kevlar too...

doxilia

My Feedback: (3)

Thanks Chuck,

Advice taken. PM replied to.

David.