Katman

Thanks for that info Laurenne...cordless drills a no-no. I believe mine turns up to 1800rpm. It sounds from other owners they are fairly easy at starting from the front, the way i'm accustomed to anyway. The 2:1 gear ratio may be take adjusting to, but surely they're not as difficult as some 2-strokes. But, either way i'll plan on getting a starter. I figure a 4-blade is twice as likely to bump you as a 2-blade!

Anyone able to offer good sources on 4-blade props for the 60SP would be helpful. I am only seeing one 4-blade from APC on their site? Graupner or maybe MA?

I am curious to get a rough idea on 60SP flighttimes with an 11oz tank as well. The plane should weigh in around 7 - 7.5 lbs. With an EVO .455 i can get roughly up to 20 min. I understand Saito 4-strokes are alot more frugal than equivalent 2-strokes, and from testimonials it sounds like the RCV's are even better?

Thanks, Mark

8178

My Feedback: (17)

Is this the idea that you are thinking about http://www.rcuniverse.com/forum/m_5626431/tm.htm ?

RCV Engines

Hi again Mark

APC do a 13x13 and a 14.5x11 4-bladed prop which suit the RCV60SP. Master Airscrew tend not to do large pitches (which are essential for RCV SP engines.

In terms of fuel consumption, from what our customers say, RCV engines are one of the most frugal 4-stroke engines out there. From our figures, average fuel consumption (based on average flying - whatever that is) is around 0.4 fl oz / minute. Based on that you would get about 27 1/2 minutes. Take a look at some of the customer comments on our website - things like 'flies forever on a tank of fuel etc' so you should certainly be more than happy.

Best regards
Laurenne
[link]http://www.rcvengines.com/customer-comments.htm[/link]

Katman

Thanks again Laurenne for "coming to the rescue" with all my questions. You must be burning RCV midnight oil at all hours over there in the UK - if you don't already know you'll research it! That's a great thing to know we have someone so attentive.

You're right on APC - but i didn't find has the right 4-blades to fit the SP until at another site. Apparently APC expects you to know they're called pattern props. I found another called Zinger, a 13 x 12 i believe(in wood though). At $30, roughly twice the price of the APC but flat tipped something to keep in mind for those wanting a more realistic look for their Mustang. I guess my next question is, are 4-blades any harder to balance than 2-blades?

Ultimately i want the scale look Truturn spinner but out-the-door it will end up costing $80(thanks to 2 machined adaptors at nearly $20 and fitting it for the higher pitch prop). The spinner starts at only $39 - but reminds one of option lists on a car!) Are there any ideas for 4-blade spinners a little more reasonable to get up and flying? Otherwise i'll have to figure $100 over the 60SP's cost to get flying. The couple i checked don't have 4-blade spinners. Maybe i'm just missing a plastic 2-blade is easily notched to 4-blade, and RCV users have done that? Plastic works, that's what i have now. Truturn's adaptors confused me what's needed to fit a spinner to the 60SP. Expected i guess, at just a little over a year in the hobby the EVO 2-stroke is the only setup i've dealt with being the H9 PTS is my first plane(and virgin second awaiting a 60SP [8D]). But hey, i'm trying!

The figures you found on 60SP fuel consumption is impressive, i'm gathering RCV's are normally somewhat better vs. competition in that category which is intriguing. The port design must be very efficient compared to traditional OHV. After all, the SP series can't be lacking in rotational mass, even without valves. I'm guessing the steel rotating cylinder that also serves as the propshaft is quite heavy, causing their only downside of being a little heavier than the competition?

Thanks 8178 for the link to that detailed write-up on realistic exhaust stacks! Very impressive! It sounds like you must PM him for the kit, anyone know the cost? I may put off going so detailed until a bigger P-51(with a bigger SP!!), as the Hangar 9 PTS fuselage/cowl bottom is oddly flat and not quite scale. I haven't tackled that problem for obvious reasons!
And it's more 40 size.

For reference, the write-up says twelve 3/16 inch exhaust pipes add up to 1.5 sq inches of ventilation...pretty cool

Thanks, Mark

rc-sport

My Feedback: (12)

Mark, to give you an idea on how fuel efficient RCV engines are, I have a 270cc tank on my test stand. The SP 90 that I was breaking in ran for 30 minutes per tank at about1/2 throttle running very rich. I used only 4 tanks to get 2 hours of run time on my engine.

Katman

That's incredible rc-sport, thanks for that info! I'm so anxious to get my 60SP ready to blow a gasket, just have to wait a couple more wks! [:@]
I'm curious if there's another more active RCV owner forum...this one seems awfully quiet for long as RCV's have been out there. There's forums "talking Saitos" galore!

rc-sport

My Feedback: (12)

RCV isn't as widely excepted in this arena as Saitos because it's "different". I get a lot of "why'd you go with that motor?" when guys see it.

DVM100

Hi Laurenne,

I've got a 120SP and I've just taken delivery of a 15.5 X 12 4 BLADE which looks pretty small on my KMP Spitfire due to the 4.5" spinner. I note you recommend a 14.5 x 11 4 balde for a 60SP and wondered why the 120SP dosn't swing a bigger 4 blade? One of the guys on YT International forum uses a 19.5" x 12 5 blade on his electric conversion of the KMP Spitfire and I was hoping you might recommend a bigger 4 blade? Say 17" maybe??

Dave

blw

My Feedback: (3)

270cc is 9.1 oz in case anyone was wondering

mboland

My second 120SP has failed.
First one failed on the engine stand on the 4th tank of fuel.
Second one failed in the air after a dozen flights or so.
Both had the pinion gear fail.
I have another 2 already bolted to a Black Widow I am assembling but have removed one to run it in the Corsair.
Not sure I can trust 2 of these in a twin engine plane.

RCV have not offered to replace the second motor but want it shipped over to them (from Australia).
The first motor cost $70 to express air it, and here is another cost, then add more fuel for running in a replacement before fitting to an aircraft.

I am finding my decission to go with RCV is now difficult to uphold at the field when long time modellers are using OS and Saito that have run for 10 years or more right out of the box.
When putting a big twin in the air the motor reliability is paramount.

There is also the mufflers that get destroyed. If you have an RCV muffler, toss it, and fit an OS muffler. They have the end plug welded in place, or get a friend to MIG weld the end plug in place on the RCV muffler for you.

I am also seriously thinking of tossing their carby's and fitting more reliable and better tuneable ones.
Has anyone done any work on their carby's?

fiery

My Feedback: (2)

mboland

Sad to hear of your predicament.

I bought one of the first 60's to come out ... it was called a .60plus.

Ran well, never a problem. It came with an Irvine JetStream Carb, like the all the early RCV's. It throttled flawlessly.

RCV went over to a "chinese" carb when Irvine ceased manufacture in England. I would look for an equivalent sized JetStream to fit your engines.

Ripmax (www.ripmax.com) sell the Irvine JetStream Carbs as spare parts for Irvine engines.

Cheers

fiery

mboland

Thanks , I will chase that up.

R/C Lee

My Feedback: (3)

Laurenne, I'm collecting all of the goodies for my winter's project, a Don Smith 89" Me Bf110. From what I understand, it'll run around 18-22 lbs finished. I fly at around 3500 feet here in Oregon, and I'm wondering if the RCV .91s would be adequate or the larger 130s would be better. Around here, a little extra power can come in handy due to our altitude/density issues, and I use the throttle a lot. What would you recommend, the 91s or the 130s? Thanks, Lee

RCV Engines

Hi Lee

Further to your enquiry. Looking at the likely finished weight of your model and the altitude you fly at we don't think the 91CD will be powerful enough for you and think that the 130CD would be more appropriate.

Hope this helps.

Many thanks

Stephanie

Pit-Viper 1

My Feedback: (12)

Yep, I had a .91 on a 12-13lb. Spitfire and it was barely enough for scale flight. Hope to see the 130 around our area some time soon.


Shane

R/C Lee

My Feedback: (3)

Stephanie, that's what I wanted to know and I appreciate your response. We have an RCV dealer here in Central Oregon and I'll talk to him about the 130s this fall. Thanks again, Lee

R/C Lee

My Feedback: (3)

Stephanie, another issue is how do the RCVs run inverted? Are they subject to hydraulic lock the same as regular piston engines, and will they flood easily if mounted inverted? Since the carb barrel is located above the engine centerline, where should the fuel tank be located (above/at/below and by how much) with respect to the carb barrel if inverted? Also, is it a good idea to put glow ignitors on when mounting inverted so I won't have an engine out on throttle back? These will be going in a scale twin, so I'm very concerned about reliability if mounted inverted. Thanks, Lee

GMV

Hi guys, i need your opinion about vibrations this engine (60-SP) produces compared to a standart 4T.

thanks in advance

mboland

Hi R/C Lee, I have a 58CD setup inverted in an AT-6 ARF, which like all ARF's, have the centre line of the tank in line with the crank.
This will cause problems for all 4S motors, inverted or not. 4S motors are sometimes a beast to tame when inverted.
My problem was that when the engine was tuned on song, going inverted would cause a flame out (too lean).
When the engine was tuned very rich, no problem inverted, but poor performance in normal flying.
Being at half throttle when going inverted did not produce as marked a lean out as full throttle (as you would expect).
I solved the problem by using a pumped header tank placed at the level of the carby. The header tank is produced in Queensland, Australia and called a 'NIFTI'.
I am also currently setting up a Black Widow with 2 120SP's and would not consider any twin without on board glow. Mine is programmable and selectable from the transmitter.

mboland

Hi GMV, The SP motors all seem to vibrate a lot more than standard 4S motors. The 60SP is little different from the 120SP, which can rattle you fillings out.
In chasing this up in different forums, the comments that keep coming forward are that the motors slooth out with continued running.
I am still waiting to see this happen as the motors I have are still quite new, but the more they run the better they get.

R/C Lee

My Feedback: (3)

Thanks for the input, mboland. As you can see from the RCV site, inverting the engine puts the carb on the CD very low. I had thought about two smaller tanks located one in each nacelle, somewhat centered on the carb barrel, with a larger feeder tank in the fuselage around the cg. The nacelles on the Me Bf110 are a little small, which may well preclude a large tank for each engine anyway, so that might be my solution. It does complicate the fuel feed system a little, and on a complex model like this, I'd rather be less complicated than not. Another thought is to mount the engines horizontally, but the heads would stick out too far from the nacelles for me. Hmmm, I'll have to give this one more thought. Lee

mboland

Today, Sunday, I have had engine number 3 fail in flight. All 120SP's, this one having arrived back from the Australian distributor on Friday with a clean bill of health lasted only 5 minutes in the air at which time loss of power forced me to land.
The loss of power was due to the exhaust breaking, yet again, just before the pressure nipple and therefore the tank lost pressure. Landing was achieved within 20 seconds.
This flight was conducted as per the instructions from the supplier, as were the modes on the cowl, larger air exit, nearly 6"sq, lip on front of opening to stop any laminar flow problems, run on the ground for 3 minutes to check for any heat build up in cowl (there was none).
The first 120SP failed on the 4th tank on the test stand, the second failed after 10 or so flights.
They are telling me that engine 2 was overheated.
I have run fuels exactly to RCV's specs, tuned for slightly rich running to avoid any heat build up.
The model is a Corsair which has plenty air inlet area, and the internal baffle installed as per RCV's instructions.
Has anyone out there had any similar experiences with the 120SP?
I am starting to feel the excuses I am recieving are getting pretty thin.

pic of failed ingine number 2
http://www.technical-services.com.au...en%20120SC.jpg

Air inlet
http://www.technical-services.com.au...wl%20Front.jpg

Air Outlet
http://www.technical-services.com.au...owl%20Exit.jpg

mboland

I forgot to mention that the engine that failed today has a loud knock when turned by hand, sounding like a conrod about to let go or another pinion tooth giving way.

R/C Lee

My Feedback: (3)

mboland, thanks for posting your experience with RCV and the photos. I hope RCV will get together with you to help solve the problem you are having. Having spent my career in marketing, I know the effect that a bad report such as this can have on a company. With all of the available engines out there, it's in RCV's best interest to solve this one quickly. Just my two cents worth. By the way, the Corsair looks great. Is this the large Top Flite kit? Lee

mboland

Hi R/C Lee,
Thanks for the input. I am currently working with the local distributor, Command Controls, who uses Brian Winch as the technical backup.
I will be sending the engine back today for analysis.
I did take a peek inside to get some photos of this failure, but no evidence was found of any. The pinion/crown teeth were fine, as was the conrod and all other moving parts. No slop apparent in any bearing or rough running when turned by hand.
The dark oil in the motor was saturated with fine metal particles which means something is grinding to death.
The Corsair is a Top Flight Gold Edition 60 series, so the 120 is definitely not being overworked.
Robart retracts, JR PCM gear, all digital servos. She flies very well. The operation of the flaps is one of the nicest features, no trim change whatsoever, so landing decents are a breeze by just selecting which flap setting is suitable for the aproach.