RCV motors.
 

G'day to All,
I'm a new member of this site, having found it through researching RCV motors for a project.
Just posting to see if there is ongoing interest in these seemingly "challenging"engines.
I have just purchased 2 RCV 90 SP's after carefully weighing the pros & cons. Soooo.....is there anyone out there who still
has thoughts and or knowledge to share ??

Cheers, in anticipation

RE: RCV motors.
 

<div style="margin-top: 0px; margin-right: 0px; margin-bottom: 0px; margin-left: 0px; padding-top: 0px; padding-right: 0px; padding-bottom: 0px; padding-left: 0px; background-image: initial; background-attachment: initial; background-origin: initial; background-clip: initial; background-color: rgb(255, 255, 255); font-family: Arial; font-size: 12px; ">Great motors , but you do have to 'work' with them to get them under control.<div>
</div><div>If you haven't run at least 5L of fuel through them they are nowhere near run in, even then it's going to take a while, but hopefully the vibration when running will be reduced.</div><div>
</div><div>The exhaust: if it has the press in end it WILL blow off. Weld it in or replace with an OS muffler.</div><div>
</div><div>The carby is their biggest let down. WOT is set to max rpm not the fully open barrel as you would be used to.</div><div>
</div><div>Balance the prop, an expect it to take a while if you are using the APC 4 blades. They are the WORST balanced prop, off the shelf' I have ever come across. </div><div>
</div><div>Run the recommended fuel, as fuel makes a HUGE difference to their performance, especially vibration and wear. Keep an ear open for any detonation as it will destroy the pinion gear very quickly.</div><div>
</div><div>Prop it up, don't under prop it, as this also seems detrimental to it's longevity.</div><div>At present  have just put a 61SP in a SeaFury and it is swinging a 4 blade 15.5" x 12" at 4200 rpm. I will be trimming the prop to get a bit closer to 5K (aiming at 4.8K) before it's maiden flight.</div><div>
</div><div>Keep us posted on how you go with them.</div></div>

RE: RCV motors.
 

"The exhaust: if it has the press in end it WILL blow off. Weld it in or replace with an OS muffler."

I can attest to that, too! If they don't blow completely off they will at least start vibrating around making noise (and presumably if you don't replace in short order, it will wear to the point where it blows off). RCV really needs to address this design flaw, if they haven't already (I've not bought a new RCV motor in the past 2 years, but my original 90SP had to have the muffler replaced even before the 1st gallon of fuel had been run thru it... RCV did send me a much better replacement muffler free-of-charge much to their credit!).

These SP's are still awesome engines though, and they hold their value better than any model aircraft engine I've ever seen if you chose to resell it! I've seen used RCV SP engines sell on Ebay for more than retail new! I haven't seen much marketing (here in the States at least) by RCV though, I don't know why they don't market more aggressively.

- Michael

RE: RCV motors.
 

Thanks for the tips guys. Correct fuel and run in seem to be critical points.
mboland, glad to see a fellow "Oztralian" in this forum. I'm just down the road at Bundaberg so were almost neighbours!

Speaking of fuel, the recommended is Prosynth 2000 [with NO castor added]. Have you managed to find a supplier in Oz, or can you suggest

an alternative? As for props, I'm going 3 bladeand I have 2 APC's at 15`75 x 13 and another 2 at 15 x 13`5

I was unsure whether I had enough room for the 15`75 . Turns out I do but we'll see what the motor prefers.

The muffler appears to have the end pressed in, no biggie as I think I will use a different system to get the exhaust to exit where I want.

Thanks for the tip on resale value Michael, that's somewhat comforting. I,m HOPING, with preperation and some luck, that these donks turn into two

of the"good ones" that I have read about.

Cheers

RE: RCV motors.
 

Sorry I'm late on this. I have a 60SP in a .50 size Zero and a 120SP in a TFGE Corsair. The 60SP swings a 15.75x13 3-blade APC bobbed to 14" (for ground clearance purposes). The 120SP turns an 18x12 3-blade. Both engines have "a ton of torque" for their size. I run CoolPower 10% in both engines and they both run great with it. I'm getting 4200-4400 prop rpm out of the 60SP and around 4400 from the 120SP. Trust me, that's plenty of rpm to do the job! These engines really spin up once airborne. Large loops are no problem.

Mufflers are a problem. I've gone to bending my own pipes for the 120SP. I would also suggest the mufflers from weston.uk. You won't have a problem with those shaking apart.

I haven't had the problem with carbs that some speak of, but keep every bolt and screw tight and check them on a regular basis.

Good luck,
Joe

RE: RCV motors.
 

G'day Joe, thanks for your input. At present, my motors have not been run. I have to make a engine stand, but work keeps interfering.

As for mufflers, I have read somewhere that these motors are quiet enough to run just a fexible pipe. Any views on that arrangement??
Thenew Turbo Header muffler from RC specialties has also caught my eye.

Cheers, Rob

RE: RCV motors.
 

Lack of muffler pressure to pressurize the fuel system.... won't run right. All 4-stroke engines are quieter than 2-stroke engines (to my knowledge), but they still need a muffler (to the best of my knowledge).

Regards.

- Michael

RE: RCV motors.
 

Thanks Michael, as I understand it , I can get a flexible pipe with a pressure nipple for the tank and at this stage I'm looking at a Perry pump per motor as fuel may have to come from a fuselage tank/tanks due to lack of room in the engine nacelles.

I'm certainlynot after noisy and will use a muffler if space allows. Just trying topiece together the most reliableset up I can find for powering a glow twin.

Most advice says don't give yourself the pain,,but the madness in me says I gotta give it a go!

Cheers, Rob

RE: RCV motors.
 

Hey go for it! And take and post pics of the installation!!!! :D

- Michael

RE: RCV motors.
 

Thanks for the inspiration Michael!

Shall do, although the project is bound to be a bit long winded due to the fact that I get paid to make stuff other than model planes, but I will post piccies of the progress.

Cheers, Rob

RE: RCV motors.
 

Hi, I've been using the RCV 90 SP for about a year, - the initial experience was not too good but after taking advice from WestonI'm very happy with the engine. Basically the advice I was given was-
Don't run the engine with a fuel containing castor (I use Prosynth 10). This is contrary to the instructions that came with the engine recommending Duraglow 10.
Don't run the engine without a baffle, either in a model or on a test stand. Weston recommend abox structure with 2 sides and a rear fitted closely to to cooling fins.
I've found that since I followed this advice the engine runs and throttles perfectly without overheating. I use a four-bladed APC prop and this flies a 10 pound model (Short Seamew) at half throttle.
Hope you find this useful.
Cheers.

RE: RCV motors.
 

Hi seamew, thank you for sharing your experience. It would seem that fuel with NO castor is the key.

It is of interest though, that you say to use a baffle, and by this,may Iassume you mean a scoop to direct air over the cooling fins?

I had it in my mind that, on a test stand, because of the open arrangement, air ducting would be unnecessary. Could you clarify this point for me?

My project is a 1/12 scale DHC-4 Caribou, and whilst the cowling is not enclosed to the point of eg, a Spitfire, I'm keen to give the motors all the cooling they recquire.

I am at the point of fabricating a plug to make a f/glass cowl, incorporating extra inlet and outlet vents to get the extra cooling I need. Will post some pics soon [I hope]

to hopefully get advice if I'm on the right track.

Cheers, Rob

RE: RCV motors.
 

Hi Rob. Yes, a scoop is a better description than a baffle. If you go to www.westonuk.co.uk and click on the RCV engines page they give advice on cooling and also an example of the scoop required.  Regarding running the engine on a test stand I found that my engine ran HOT! unless kept very rich, even though it was in the open. Hence my call to Westons when I was told that a scoop was still advised, especially if the engine is new.  I hope it goes well, - once these engines are set up properly they are very good.
Cheers.

RE: RCV motors.
 

Thanks seamew, that is VERY interesting advice, a scoop on the test stand it shall be!!

Cheers, Rob

RE: RCV motors.
 

In my experience with the 60SP and the 90SP the engines, a scoop is necessary even if the engine is not cowled (like on a test stand). Cowl or not, on a test stand or on the airplane... have something the to direct the cool air in the right direction through the fins.

RE: RCV motors.
 

New engines always run hot no matter what... the parts are tight until they wear in a bit. I've broken-in 1 RCV 90SP on a test stand (without any form of air redirection) and it seems to be just fine. Air goes everywhere after all, there are no dead-zones where air fails to move such as can be found inside a cowled installation.

Still, it couldn't hurt to have more directed cooling even on a test stand... but, how? I'd like to see a pic of how that was accomplished. My test stand is essentially a box mounted on a post with the engine bolted to the front. I can't imagine any good way to add an air scoop to this thing. I'm part way thru breaking in a 2nd RCV 90SP engine on it now. I've not read of anybody killing an RCV engine from overheating it on a test stand though, most heat related deaths occur when mounted inside cowlings with poor air flows and/or incorrect fuels.

Note: When I 1st ran my 1st 90SP engine on the stand I was trying to follow the instructions to-the-letter and though I fly 10% Coolpower fuel in my OS engines (a fully synthetic fuel) I borrowed 10 oz of a 10% nitro caster oil based fuel from a fellow pilot for the new RCV engine (the instructions that came with the engine were very specific about running a caster oil based fuel). It was smokin HOT after a 10 minute run at < 50% throttle! Too hot to touch for almsot 10 minutes after the run. Yikes! After checking on this forum, I was told by RCV rep that full synthetic oil fuels such as CoolPower would be ok in their engines, and the next time I ran the engine with a tank of Coolpower 10% it ran MUCH cooler and I could actually touch the engine without being burned within seconds of shutting it off. While not scientific (I don't have a temp gun), I'm positive that these engines run a lot cooler on full synthetic fuels. So, the fuel you use can make a tremendous difference on how hot these engines run as well. Plus, I hate caster oil, that stuff makes a mess of engines. Ughhh!

- Michael

RE: RCV motors.
 

Hi Michael, I'm glad to hear you agree about non-castor fuel. Like you I find that engines run cooler on fully synthetic.
Regarding using a scoop on the test stand, I am following advice given by Westons. They have an example of the recommended scoop on their website. Go to www.westonuk.co.uk and click on RCV engines to see it. I've no doubt that some RCV engines are tighter than others when new and therefore will run hotter until run-in. It would seem that my example was one of the "hot" ones. The important thing is that it's now really nice to handle and I will be buying a 120 SP soon.
Cheers.

RE: RCV motors.
 

I must be missing it then, cause I don't see any pics of test stand mounted engines with a scoop on the stand. [&:]

- Michael

RE: RCV motors.
 

No Michael, there isn't  an example of any test stand set-up. It just shows an example of the type of scoop to use, whether on a test stand or in an aircraft. The advice to use the scoop on a stand was given to me on the telephone by a  technician called Alan at Westons UK. You can talk to him on 01795 521030 if you need any further confirmation.

RE: RCV motors.
 

In response to "I've not read of anybody killing an RCV engine from overheating it on a test stand though" I have to tell you that I have managed to kill a 120SP on the test stand.

Motor sitting in free air running a 2 blade 20" x 12" I think it was (whatever was recommended as a run in prop in the instructions).

I think you hit the nail on the head when you mentioned castor and tight engines.
This one was tight, and I was running castor as per the instructions.
It was vibrating a lot and did not sound right at the top end.
I was very careful to run it as per the runin instructions, and part way through the second or third tank she stripped the pinion gears.
It was probably detonating, but it was not obvious from the sounds it waking that it was doing this.

At that time I was dealing with RCV direct and they were wonderful.
Great customer service, I have struck none better.
If Weston can keep that level of service up I still have no hesitation in recommending these motors.

Mike<br type="_moz" />

RE: RCV motors.
 

Sounds like a bad motor, even before it got to the test stand though. What did the RCV people think went wrong?

They do have excellant customer service, that's for certain! They're fast and courtious, definitely a pleasure to work with. They don't seem to be marketing their model aircraft engines in the U.S. very much anymore though, other than word-of-mouth I never hear anything about RCV engines over here. I have the only 2 RCV engines in my entire flying club (of over 100 members!). Nobody in my club had ever even seen one before I bought my 1st. They sure need to advertise more in the U.S. IMHO.

- Michael

RE: RCV motors.
 

Thanks gentleman, My confidence in these motors grows with each post. I felt I may have been sticking my neck out a bit with this purchase,

but i figured RCV have been around for some time, they still make them and as said previously, their after sales service is legendary.

Many thanks for your input and knowledge, I hope to put it to good use.
 I do have a question regards the prop for running in. RCV recommend a 2 blade 22x18 [from memory] Can anyone foresee a poblem using the prop I hope to run, 3 blade 15.75 x 13.  ??  This is a recommended prop but  only the 2 blade is mentioned for run in.

   Rob

RE: RCV motors.
 

"Sounds like a bad motor, even before it got to the test stand though. What did the RCV people think went wrong?"

They did not come forward with any definite explanations, just replaced the engine.

I presently have a 60SP installed in a Sea Fury that awaiting its maiden flight, as soon as the flood water recedes here, and the flying field dries out, it will be a goer.
It ran very well on the test stand for nearly 80oz of fuel.
The more they run, the smoother they get.

The 2 58CD's I have always run well, although both need new airframes now.

<br type="_moz" />

RE: RCV motors.
 

The 90SP needs a 2-bladed 18x12 prop for proper break-in. I presume this is what you meant? Break the engine in for a gallon or so of fuel on a test stand with this prop, then get a more scale like prop if you like. This prop makes the engine run at the proper RPM's so as not to damage anything while the internal parts break in. Do build or buy a test stand, as these engines are quite rough running initially and may damage an airframe until they smooth out. Also, BALANCE the prop before bolting it on, don't assume it's balanced!!! The Master Airscrew 18x12 prop I bought from Tower required quite a bit of balancing, it was bad out of balance.

- Michael

RE: RCV motors.
 

Hi Mike. Regarding your overheating problem while running on the bench. I would suggest that if an air scoop had been used thismight not have happened. I know that at the Weston factory they use such a scoop when running these engines on their testbed. That must tell us something!

All the best.