OPS 120 20cc available in the USA?
 

Does anyone know if the OPS 120 is available in the USA?

The specs on this thing are impressive: 5.5 hp @ 24,000 rpm!!!

http://www.mantuamodel.com/index.php...elli&Itemid=92

RE: OPS 120 20cc available in the USA?
 

i ordered the 90. unfortunately it arrived in marine version. i am sending it back for a aero version. it took about 4 months to order and receive.

RE: OPS 120 20cc available in the USA?
 

Well, we all agree that using the 20 cc OPS engine beast is determined by certain boundary conditions:
[ul][*] Like all speed or ducted fan engine it is high-timed (exhaust duration ca 180 degrees). That results in rpm above 20K. But to achieve these desired rpm numbers and the associated 5HP+ output we are forced to use rather small diameter propeller. In case of the 10 to 20 cc OPS engines only a prop diameter smaller than 10” will allow the prop tip staying below transonic speeds which is fundamental![*] The load of the mostly distinctly “oversquared” purpose built speed props must be adjusted right – no easy job if you really want to reach your top speed target number! For the OPS .90 to 1.20 RIRE DF engines the following prop sizes will work well with a suitable airframe: 7.5 x12.5”, 8x12”, 8.5x11.5”, 9x11”, 10x10”.[*] So - when dealing with such high performance engines like these 10 to 20 cc OPS “monsters” - for safety reasons it will be necessary to make carbon fiber speed props that feature a strong hub (at least 24 mm of hub diameter and 14 mm of hub thickness).[*] In order to let these rather small diameter speed props work efficiently during flight a very low drag airframe is required. Examples of the most refined designs so far are found in Germany, preferably when talking IC glow powered R/C speed up o 20 cc. Top speeds up to true (FAI compliant) 240 mph are the status quo for the regulatory F3S-C class.
[/ul]


Please visit this thread:

[link=http://www.rcgroups.com/forums/showthread.php?t=984610]German F3S Speedcup – info, pics, videos[/link]

So it is clear that purchasing these 10 to 20 cc OPS speed engines only makes sense if all of these prop & airframe design related demands are met. These heavy duty engines must operate above 20.000 rpm to work efficiently. They are designed to service many many flights without the danger of technical failures at WOT (with open speed venturi carb for maximum output if you like) - even occasional lean runs do not harm these “ABC” or “Bimetal” engines if using at least 20% of oil content (of which at least 50% castor is highly recommended). However, if we don't let these OPS engines run in their correct power band, then we should better use them as nice paperweights or collector's items in our glass cabinet. [sm=wink_smile.gif]


This is the [link=http://www.rcgroups.com/forums/showthread.php?t=970617]The OPS engine thread[/link] coming with additional info for the interested speed freak:
http://www.rcgroups.com/forums/showthread.php?t=970617

RE: OPS 120 20cc available in the USA?
 

With respect to the availability of OPS aero & marine engines in North America, it would be fine to find a company or a business person that will start selling them again (after Shamrock, Tower and others have stopped distributing these high quality OPS products years ago). In Europe for example there's a constant demand due to advancing serious speed competition within the different FAI regulated F3S classes. In fact no other commercially available speed engine to be used in the F3S-C class (6.61 to 10.00 cc, this is the class to break speed records) is as powerful as the 5-ports OPS .60 Super SPP VAE.



When looking for OPS 1.20 RIRE suitable commercially available speed planes there's only a small number of choices:
[ul][*] Messerschmitt ME 163 B 1a Komet by Sunshine-Wega[*] Cobra by Fliegerland[*] Phenom by Oakdale Aircraft[*] Mirage 2000 by RC-Tronics-Topp-Rippin OHG [*] F-102 Delta Dagger by RC-Tronics-Topp-Rippin OHG [*] ME-163 Komet by RC-Tronics-Topp-Rippin OHG [*] Blizzard by generic-fly
[/ul]
The above fast and rugged composite planes represent acquirable speed planes
[ul][*] that will cope with the outstanding 5.5 HP power output of the OPS 20 cc ducted fan engine (#86115) and also [*] whose aerodynamics will allow the required small prop turning at 20K+ to transfer rpm into top speed efficiently. [*] Some of these above listed speed planes are true 200mph+ aspirants with the right engine / carbon fiber prop combo!
[/ul]

For details please take a look at this thread

containing a list of quality composite speed planes.



P.S. These OPS 15 and 20 cc RIRE ducted fan speed engines basically are bored-out OPS .80 (5+2 ports) siblings weighing almost the same. They come with additional tungsten weights implemented into the counter-weight of the crankshaft. The familiar needle-bearing conrod of the OPS .67 and .80 has been taken over as well as the (optional) drum valve induction unit. In consequence these “super short-stroke” engines won't achieve more top rpm than the OPS 80, but they offer more punch to turn slightly more prop pitch with authority than the 13 cc OPS .80.

RE: OPS 120 20cc available in the USA?
 

Attention please – this only happens once in a decade!

There are several NIB gold head 5-ports OPS .60 Super SPP VAE speed engines offered on the large bay auction site. This is THE engine to break FAI speed records!
In addition equally powerful OPS .67 VAE engines are offered sharing many parts with the .60 VAE. I am not affiliated with the seller BTW...

RE: OPS 120 20cc available in the USA?
 

Hi ILJ, thanks for the leads. Six engines in all.

I just got a good deal on a Rossi 90 DF, brand new. This one will go in the first prototype of the fast plane I am designing. Check my other thread. Any prop suggestions will appreciated.

Ed

RE: OPS 120 20cc available in the USA?
 

i grabbed one of the .67's [sm=tongue_smile.gif][sm=teeth_smile.gif]

RE: OPS 120 20cc available in the USA?
 

So that was you!!! I made a couple of tries but $227 is a bit too high, I think. Anyway, congrats. What airframe is it going into? I was thinking of trying it on one of our new prototypes (check my other thread "New fast airframe...".

RE: OPS 120 20cc available in the USA?
 

i will probably look at it for a few yrs. they don't come along very often. i've seen them sell for over $350. there were plenty to bid on though. the most i've ever seen. i will keep an eye on your thread, and maybe buy or borrow your design someday.

RE: OPS 120 20cc available in the USA?
 

Excuse my ignorance. Im not a real expert in fast planes, but what is the difference/advantage of the OPS 67 vs a Rossi 90 DF for example? I just got the latter and it is impressive (not run yet).

RE: OPS 120 20cc available in the USA?
 

I-L-J would have a answer. i would guess the Rossi is among a handful of the most powerful engines there are.

RE: OPS 120 20cc available in the USA?
 

For prop applications the advantage of the OPS .67 RIRE ducted fan or speed engine vs the ROSSI R90 DF engine is not easy to determine.

Both engines reach the power/torque peak when running in excess of 20 K. So in both cases the prop diameter should not be larger than 9”.
But a 15 cc DF engine generates more torque than a 11 cc DF or speed engine and thus is able to pull slightly more prop pitch at the same prop diameter.



So which of these two engines to be used for better top speed? Well this entirely depends on the airframe drag.

In case we have a super sleek speed airframe design ready to fly loaded with many drag reducing finesses, then Ipersonally would tend using the OPS .67:
[ul][*] In general smaller speed engines are capable of turning more rpm (the actual 5+2 ports OPS .67 is able to spin up to 24 K stock and 27K if highly modified) than bigger IC speed engines
[*] Now we can apply prop pitches exceeding 11” effectively, especially during unloading in a dive from high altitude
[*] The belly diameter of a 11cc tuned pipe is smaller versus a 15 cc pipe => a narrower fuselage can be applied
[*] A smaller engine does consume less fuel per time unit => increased flight time when using the same bubble tank volume (usually speed engines don't feature a throttle carb)
[*] weight reduction due to the smaller engine => lower wing load
[/ul]


However if the speed plane design is not the most sophisticated ;) (e.g. the [link=http://www.rcgroups.com/forums/showthread.php?p=12734995#post12734995]Speed Cobra[/link] ), then 13 to 20 cc ducted fan engines are mandatory. These “big-block” engines provide enough peak torque needed to overcome increased airframe drag by using reduced prop pitches (e.g. 9”x10” CF props).

RE: OPS 120 20cc available in the USA?
 

Thanks again for the comprehensive explanation. The 90 looks for our project then, as I want to make slightly larger wing. As I supposed, the added torque can be useful to drive this larger wing, reducing wing loading and thus gliding speed. Still, those OPS´s looked very attractive. I was even thinking of putting one in a stock Magnum w/ enclosed pipe. Thant would be a good combo for DHAL22 for a quick and easy trip to speedland.
Ed

RE: OPS 120 20cc available in the USA?
 

ILJ, i always enjoy your posts. please continue to post as often as possible. i will open a thread on my engine when i receive it.

RE: OPS 120 20cc available in the USA?
 

Better add your questions to The OPS engine thread: http://www.rcgroups.com/forums/showthread.php?t=970617

It is more comfortable for the speed folks to find OPS specific info concentrated in a single thread...

RE: OPS 120 20cc available in the USA?
 

thx for the thread reminder. i don't visit that site often.

RE: OPS 120 20cc available in the USA?
 

what a great thread. any OPS fan will love the info there.

Hello everyone for all your OPS needs marine, buggy or on-road check out gotnitroonline.com we carry full line of engines parts and manuals. Anything we don't have would be happy to order for you. We of course carry the OPS 120 and the new Bi-Metal 90. Give us a try you won't be disappointed with our fast friendly service.

Oh yes GotNitroOnline.com carries all your OPS marine needs engines and parts.

Is that the Bi-Metal 90 aero version? I ordered the engine in '09 from the UK and it arrived marine style. I sent it back and never received an email on the aero version being available.

Hello thanks for your question and I checked with OPS and received back response this morning. They can supply also 90 bimetal in aeroversion. They change the head and front end no cone but spinner fixing. The price is the same as on our web-site and we can special order this for you if you want takes approx 2 weeks.