MJD

My Feedback: (1)

Got one OPS .65 in the mail today, this one was listed as having been run about 10 times and I was told it is tight on top. I disassembled it today and all in al it looks okay inside at least, and it was evident there was a lot of castor in the fuel it was run on.

Right mounting lug looks like it got caught fooling with another man's flight box, been beaten on a bit, but I can clean it up.

Here is what I see with piston liner fit, how does this sound:?

Piston has some carbon on top, perhaps 10 mils at the thickest spot, but clean around perimeter other than near exhaust port. Oh boy I thought, someone from the old school of "bullst, run 'em slobbery rich" got their misguided hands on another fine Italian engine and f-ed it up on the first runs. But the fit is as follows: if I support the piston by the conrod and let the crankcase and sleeve weight slide down on its own, it gets to about 1/8" from the top of the sleeve. With some finger pressure it reaches about 1/16" frm the top, and with a lot of finger pressure I can get it just about flush with the top of the sleeve. Note it is well lubed with residual castor oil and some preservative too it seems. It takes a bit bit of a push to get it free and back into a downstroke. But I don't feel a "squeak", just lots of resistance. I guess this is the film of castor spooge doing its job?

This one has a Perry carb, I want the OPS carb instead. Have to see if I can find one identical to the other. I can use the Perry elsewhere if it works.

MJD

bob27s

My Feedback: (19)

Sounds like it is in great shape in general. Needs some run time and TLC

Clean it with a bit of air tool oil or similar..... tends to loosen the carbon and stuff.

Then toss it on a test stand, add on a pipe of some sort... bolt on a light prop and let it howl at rpm (while a little rich). Use what ever fuel you have .... 10-15% is fine. Get something with a big hub on it and cut it down (12x8 down to about 10" dia)

You might be surprised by the fit/squeek once you run it a few minutes like that.

combatpigg

My Feedback: (3)

I would not forget ILJ's advice to resist the urge to push the piston past TDC by hand. You might not realize the microscopic wear when doing that.

MJD

My Feedback: (1)

Yup, good point. I never got it closer than maybe 1/32" or so from the top of the sleeve. And it feels well "tempered" with castor.

Did OPS ever use Perry carbs, or were their RC engines always equipped with OPS carbs?

MJD

p.s. how does the tank work?...

rmenke

My Feedback: (13)

You can find Perry carbs on about anything except a SS Jett. I have a OPS with a OS carb fitted to the back plate for more fuel/air by one of the German engine nuts who does fine work from what I can see. None the less, the thing scares me with the cut down piston skirt, lightened rod and crank. Probably never see anything with wings around here, but the estate sale should bring good money. ENJOY

rmenke

My Feedback: (13)

You can find Perry carbs on about anything except a SS Jett. I have a OPS with a OS carb fitted to the back plate for more fuel/air by one of the German engine nuts who does fine work from what I can see. None the less, the thing scares me with the cut down piston skirt, lightened rod and crank. Probably never see anything with wings around here, but the estate sale should bring good money. ENJOY

dhal22

i have an OPS speed 60 with an original carb but it also came with a 2nd backplate that has a perry pump on it and a matching perry carb.

david

I-Love-Jets

Well, a 10“ diameter prop would be too large in general for any ultra high performance engine ranging from 10 to 15 cc. Their timings are mostly optimised for a minimum of 22000 rpm.

You need to go to 8“ of prop diameter in order to avoid performance-killing transonic tip speeds. [8D]

So both the ground test prop and the final carbon fiber propeller for flying should not be larger than 8“ to ensure reaching the wanted engine power band.

A big hub ZINGER wood prop would be well suited on your OPS .65 RIRE for break-in purposes. I’d take the Zinger 11x10“ (#513) to be cut down to 8“ of diameter to load the OPS correctly on a test stand.

The original OPS slide type carb (see below) being too expensive to buy separately you will find included to the actual blue head or past years red head OPS .67 marine engines. These .67 engines as perfect spare parts suppliers for any OPS .65 will also provide more top end power than the .65 due to the refined 7-ports piston/sleeve assembly.

All needed information concerning pipe length, choice of plug ... the OPS freaks will find here for instance:

MJD

My Feedback: (1)

Well, I-L-J, I think you've answered about every possible OPS question I could come up with.. thank you!

Oh dear.. two .67 piston/liner sets.. $$..

MJD

bob27s

My Feedback: (19)

think about it for a minute.....

When you go to start this engine (or any ABC type engine), it is going to be pushed past the top center at least 10 times a second by the starter - then about 25-30 times a second as the engine fires (assuming a low idle) while cold. Even if you started it by hand, you have to flip it past compression a few times to draw air and fuel into the engine before it fires.

Turning it over the cold engine by hand a few times is not going to damage anything as long as there is at least a little oil involved and you have not loaded up the cylinder with tooth paste or something. The piston alloys are much more robust than that.

The 10" cut down prop (from 12x8 to 10x8) was not intended as an application prop - only as a tach prop and "run in" load on the bench. Gives reasonable load, a decent airflow pattern, and the hub and blade roots are substantial. Would be good upwards of 17,000-18,000 rpm without issue. We run the Jett 90LX on 10x10 props (stock package blades) up over 16,000 rpm without issues as well.

As far as I know (and I recall), the OPS 65 he is looking at here is not designed for running at 22,000 rpm - its not timed for that like the marine version, and the intake design and carb does not support that in stock configuration.

The OPS .65 I played with I sold to a CL speed guy (might have been carrier?) long ago. Yes, it went fast for him... but by the time he was done with it, the only thing OPS about it was the crankcase and maybe the cylinder head bolts.

But it has been a bunch of years since I played with an OPS anything, so I will defer to those with a lot more hands-on time.

MJD

My Feedback: (1)

Well, I did wonder about that concept... how the hell do you start them if you aren't allowed to turn them through TDC? It didn't worry me, there is a decent film of oil on everything.

From what I have gathered here, these .65's use a 5 port liner, while the marine engines use 7 ports and are timed for 22k or so, while the aero version seems to be set up for peak power around maybe 18K. Or perhaps I have completely missed the mark and need to read it all again more carefully.. [sm=tongue_smile.gif]

I'll certainly get an idea of what they are about once I get one on the test stand.

MJD

I-Love-Jets

Well all OPS .65 RIRE goldhead 5-ports engines were intended as ducted fan engines primarily. This is the reason why they came with the regular prop driver instead of the integral type speed aluminium spinner (that highly recommended spinner is a direct fit to any RIRE OPS .60 to .80 however).

The RIRE OPS .65 DF liner and intake timings were identical to the OPS .65 goldhead marine engines (the ones with the water cooling ring around the cylinder).

So yes - his OPS .65 RIRE engine, if not changed from stock condition, is timed for rpm regimes exceeding 22K if propped correctly. On the test stand the Zinger 11x10 cut down to 8x10 and rebalanced should provide the correct load. Please do not use a tuned pipe being too restrictive - The OPS must be able to "breathe"! Well suited tuned pipes (muffled or straight) have been listed in the other OPS thread.

All OPS .67 piston/liner assemblies are a direct fit to any .65 OPS engine. The actual .67 assy (7-ports) is timed a tad more agressively while cooled better than the .65 assy due to the additional 2 ports.


Sadly we cannot use an OPS .65 or .67 piston/sleeve assembly in combination with the .60 OPS 5-ports cylinder housing (being used for all .60 FIRE and RIRE goldhead versions). That would lead to wrong compression ratio and messed up timings...


You should invest into a complete brand new OPS .67 blue or red head marine engine rather than into different separate spare parts such like two .67 piston/sleeve assemblies, spare conrod, spare carb etc.

MJD

My Feedback: (1)

Cool.. I think it is safe to say that nobody at either of the places I might fly have heard a piped .65 running over 20k, at least on a prop plane versus a DF where you would expect to hear such unearthy sounds. And certainly not a pair of them on a twin. I hope my neighbours enjoy the test stand and ground runs..

I don't know if you or anyone else can answer this or not, but is OPS in good shape in the business of marine engines etc., and likely to be around for while? I am wondering how soon I should worry about parts you see.

MJD

combatpigg

My Feedback: (3)

I believe that the cylinder should be pre-heated to maintain the original pinch as long as possible and to put less stress on the other moving parts. Some 1/2A AAC engines are set up so tight that you can break something before you get it broken in. I see no harm in using this advice, just extra effort.
At some point all engines will loosen up enough to make special handling a moot point.

MJD

My Feedback: (1)

I am sure you will prolong the life of the nice fit this way, seems sensible to me. But yeah, the caveat is that you need to have something at the field to warm them up. The effort expended all depends how important it is to you I guess!

Based on the timing of these engines, perhaps my plan of twinning them on a Duellist 2/60 is a waste? Hmm, I better take a look at that wing and see how thick it is. Maybe a pair of something else would be more sensible. Not that I prefer sensible, insanely overpowered is more the ticket, but these might be running too little prop for that thing. The alternative is always single engine Speedcup-type models, and if I get one of those in the air with one of these .65's, I might start yawning at the Magnum.

No matter, I have lots of time to daydream about such a problem.

MJD

I-Love-Jets

Well if an ultra high performance ringless ABC or AAC engine that is intended to perform at full throttle only has been broken-in properly, then you normally don’t need to take the heat gun out to the flying field.

But before starting, any brand new ultra high performance engine must be pre-heated at the cylinder fins to reduce the top dead center piston pinch in order gain as many engine runs as the material will allow without excessive loss of top end power.

Each piston/sleeve assembly that has been broken-in correctly is good for 100 to 200 full throttle runs at least. The conrod fit & play & wear should be checked every 50 runs prophylactically.

I-Love-Jets

For a Duallist (twin tractor powered) these OPS .60 to .65 RIRE speed engines are not the perfect choice because of this plane’s amount of parasitic drag.

So you should take two .60 sized FIRE performance sport engines instead such like JETT .60 LX, driven by 10x7 APC sport props for instance. As a general rule for R/C prop driven speed planes it turned out that a single IC engine powered plane generally is equally fast, if not faster than its twin powered brother. For that we won’t find any twin IC powered speed planes designed for the EURO Speed-Cup for instance. What really matters on a twin project seems to be the brutal sound... [sm=tongue_smile.gif]

Even with a .40 sized Mustang or similar design the OPS .60 to .80 RIRE engines should not be combined because these semiscale planes are too draggy already (they mostly require a prop diameter of at least 10“). Moreover the often wooden (ARF) plane construction such like Duallist, Mustangs, Spitfires etc must be reinforced in order to cope with the HP of the high timed OPS speed engines.

So it is obvious to obtain or to design and built an EURO Speed-Cup type super low drag speed plane (non-wooden construction) being perfectly suited for any 10 to 15 cc ultra high performance engine in terms of airframe structural integrity and drag (high pitched 8“ or less diameter CF props can be used without efficiency loss).

I-Love-Jets

I think it would be beneficial for all of us speed addicts to keep the traditional Italian brand OPS alive as long as possible by buying their products regularly.

Remind: The ultra high performance OPS RIRE aero engines were not available for the past 15 years due to non-existing demand (no German Speedcup took place from 1991 to 2003). []

As far as I know the former family business OPS has been bought by Mantuamodel from Italy some years ago to keep it alive. OPS does focus on R/C car engines mainly but are clearly dominated by NOVAROSSI (brother of Mr. ROSSI) today.

The .67 and .80 marine speedboat classes have never been dominated by OPS or ROSSI (Italian) but by PICCO (Italian) and today CMB (Italian) and MAC (USA). However highly modified OPS engines won many marine heats as well...

The very well designed and built PICCO marine engines completely discontinued few years ago sadly and will never be revivaled. Mr. PICCO actually was the character “P“ of the name O.P.S. because he was chief designer from 1968 to about 1979 for all OPS engines. Then he decided to start his own business. Because OPS came out with the very powerful patented 5-ports 10 to 15 cc engines in the early 80s, PICCO had to go a different route (namely 4-ports) being very powerful as well. Now as a retired person Mr. PICCO just makes a few CL-line speed car engines per year for himself mainly (hobby).

The PICCO ducted fan and aero RIRE speed engines (pic below) also discontinued in the 90’s [] and are rare and expensive collectors items today if NIB. Below pictured PICCO .60 RIRE (special limited edition) speed engine was the main rival of the OPS .60 VAE goldhead during the German Speed-Cups in the 80's.



Also ROSSI ducted fan and aero speed engines discontinued and won’t be available in future again. []


To conclude:
OPS offers ultra high performance aero speed engines that are needed power-wise to break FAI world speed records for instance. But OPS already had discontinued them for a decade. So we are lucky to be able to buy them now.



P.S. Below pictured are some pages of the year 1993 OPS catalog. In 1993 the proud family brand OPS celebrated the 25th anniversary.

dakota97

I recently acquired an OPS 65 Speed RCA. It's brand new in the box. Does anyone have any info on this engine? Thanks!

MJD

My Feedback: (1)

I would start by reading through this thread filled with info by I-L-J, that started with me asking questions about the same engine:

http://www.rcuniverse.com/forum/m_7954952/tm.htm

It is a beast of an engine. And you can drop in a .67 piston/liner set for more top end.

MJD

dakota97

Any idea how much a NIB OPS 65 Speed RCA is worth?

MJD

My Feedback: (1)

If they appear on auction NIB I would expect to pay a minimum of $250 (if you really lucky) and expect $300+. I bought two used, one for $260 and one for $190. The $190 example had some hangar rash and abuse, but internally was okay but I have my suspicions about how it has been run. I'll find out soon enough on the test stand.

I'd say new today they would be about $375 retail.

MJD

MJD

My Feedback: (1)

Oh darn - I wish I had read your message on the other thread first! [:@]

If I knew you had one yourself - versus looking to buy one - I would have said they were worth $175 tops but I'd give you $200 because I collect them.

Doh!

But seriously, you got one fine engine there. Are you thinking of selling it?

MJD

dakota97

I'll list it. Thanks.

I-Love-Jets

Update: [sm=thumbs_up.gif]

OPS has just released a new 15 cc high performance engine!

Some OPS 90 “bimetal“ info:

http://www.rcgroups.com/forums/showt...7#post12100461