RCV 120SP Failure

[Jon Black]

try these peopl, i,ve found them to be very helpful in the past http://www.macgregor.co.uk/

[Tom Sharp]

Don't talk to me about Saito, they are dead boring, they start up instantly, do the flight without incident, then the same again the next day, and the day after that. Where's the fun in that?

[Michael Boland]

Those are the exact same symptoms I have been experiencing wiht my 120's.
I ran them in for 2 hours on the test stand, but even after another 3 hours in the air it was still vibrating, running poorly in mid to low, blowing mufflers apart and very very hot.
The motor was just starting to noticeablt settle in and could be tuned for smoother running, but unfotunately it failed.
I think they grossly understate the runin time for these motors. It should be more like 10 to 20 hours than 2 hours.

Australia now has a local warranty repair agent, Command Controls, and both he and RCV have given me the formula of setting the idle needle to a 1mm gap at the spray bar with the throttle body held open, then a drop of resin down the idle screw hole to make sure it does not move, and should never need moving. Have yet to try it.

I have just stripped the good engine out of the Corsair at CC's request and sending both motors back to them for analysis.

I will keep this thread posted with any updates.

[Michael Boland]

I have to source a new supply of Nitro as the stuff I have been getting is the Chinese, but some Angus can be sourced locally. I will try the 15% for more cooling and let you know, but it will be a week or two before the motors are back and installed again.

To gap the idle needle I used the shank of a 1mm drill bit which I could easily poke down the carby and slowly adjust the idle needle till I gained an interference fit.

The other fuel mixture I will be trying is just 20% Coolpower, no Nitro, no Castor.
I usually run 5% Nitro but have tried 10% with no discernable difference.

The next runin procedure might be to hook up a 5L container and let the motor run for a day or two ;-)

[Michael Boland]

I have runin and installed a 60SP for a friend, and we had problems getting any smooth running at mid to low range.
But the plane had a midair on it's 5th flight, so until it gets more running time, we wait and see. What I had noted in the short time of use was that the more running time it got the better is sounded and ran.
In the bad old days it was not uncommon to have to put some lapping compound (Brasso:-) of some sort in the fuel to run the motor in as the parts were of such tough quality that they would not 'wear in'. After having investigated inside these motors after they have swallowed hardened metal (58CD swallowed bearing, 120SP swallowed pinion teeth) I was amazed that the bore/piston/ring in both cases was totally unharmed. This seems due to the hardened steel cylinder revolving around the piston. This could also be causing the motors to NOT runin easily.

I was wondering about the screws in the muffler, there are 2 on the way to me. I was considering brazing the ends on, which I will now do.

[The real Ron Truth]

Careful please not to draw too many conclusions on rcvs based on a few experiences. Ive got a 60 sp and 90 sp and there the best engines I have, even better than a saito 150.

Sure tuning the low-mid and high end for smooth running involves trade offs for such basic carbs. As I run mostly 1/3 throttle, both mine run sweet on low revs but a bit poppy under full power. It adds to the character of a nice old biplane!!

Mine 90sp took no more than 1 hour of 1/3 power ( very rich) to run it in . Clearly though if your engines chewing gears, its got design issues.

[Mike Deans]

Hi,
Just found this thread and I also have one of these engines and as Jetsome knows from another thread I would advise the liberal use of thread lock on any screw / bolt. The carb. on mine in a Hellcat vibrated loose and lost power on its second take off and the model went in nose first ( total bin bag job ).
Have a look at this site, I have a few of his silencers inc. the 120 SP one ( not yet fitted or tried out but no way is it going to come adrift) , might be worth considering.
http://www.keleo-creations.com/Single%20Engines/RCV-120/RCV-man.htm

Mike

[Doug Ireland]

A message for Michael Boland. "The Model Shop", Murray Street in West Perth stocks Saito engines. I drooled over one of their big radials a few months ago.

[Michael Boland]

Thank you Douglas, I have also found that Model Engines in Melb have them as well.
We now have a local warranty repair in Australia and I am waiting on them for some verdict on reasons for failure, they have the dead one and a running one.
Corsair grounded again :-(

[Michael Boland]

Sadly I have a final solution from RCV on the 120SP problems I have encountered. "‘RCV have, as a matter of good will, offered to fully reimburse me with the cost of the engines in spite of the fact that it considers the failures are due to aspects outside of its control’" The local agents here in Australia, Command Controls, were just giving me technobabble answers full of holes and wrong facts, despite (or is that because of) having Mr Brian "bulldust" Winch, as their technical adviser. RCV would have to be one of (if not 'THE' ) most accomodating and responsive companies to deal with. I will probably be getting another 58CD for a small P40 I have repaired as the 58CD I have has performed flawlessly and clocked up many, many hours of air time. The 120SP's on the other hand have a problem here in Australia, and my observations and investigations indicated that it was the 20% oil mix the local agents were telling us to use. RCV resolved the issues before I had a chance to test the final motor to destruction to prove it. So anyone having vibration problems, and/or overheating problems with their 120SP, try lowering the oil content to ABSOLUTELY no more than 15%, of which 3% to 5% MUST be Castor (this is RCV's recommendations as per their manual with the motor). I look forward to any feedback on this. Bottom line: if you are having any problems with an RCV motor, deal with RCV UK direct. You will be assured of satisfaction. Just watch out for local agents in "excuse mode". _____________________________

[The real Ron Truth]

Michael,

 Good news. RCV have always impressed me in the past when I had a few queries on my 60 and 90sp.

 I agree regarding the oil content bit. I used duraglo model technics fuel for some years and never got the best from  my 60 sp. I then went to fully synthetic for my 90sp and it ran so much smoother and in my view cooler. Its interesting that some manufacturers insist on fully synth fuel, some 2-5% castor .

I just hate the mess and gunking you get with castor. Due to a recent emergency, I bought a couple of gallons of 2% castor instead of my usual fuly synth. Every one of my engines runs lumpy at tickover now and had to be run leaner, something I wasnt keen to do.