us1hydro

My Feedback: (23)

I'm thinking about putting twin RCV 60's on an F&F tigercat I just aquired. The wingspan is aprox 72" and the weight, minus engines & radio is about 8lbs. I understand that the RCV engines have special prop requirements and I'm wondering what 3 blade props would work well on this application. Where can I get them? Would the same props work on a Wing MFG P-38? How about 3 blade props for twin 90's on a Wing MFG B-25? I got a RCV90 and these appear to be very well made engines with great potential for scale models with their ability to fit inside the cowl!

RCV Engines

Thanks for your query and your comments.

Firstly with regard to the Tigercat - the RCV60SP engine has a 2:1 reduction gearing, therefore the speed at the prop is half of the engine speed. You therefore need much larger propellers than conventional engines. We recommend the use of a 13.4x13.5 propeller (or similar). You can get this actual size from www.apcprop.com. Obviously you will need to check that you have enough clearance for these propellers. Without having specific experience with these models we cannot give you definitive advise however a couple of 60SPs should have the power to pull the Tigercat.

Assuming clearance on the P-38 was okay, you could also use this size prop for this application. Another RCV user has put a couple of 58CD's in a P-38 if you are interested, see www.rcvengines.com/gallery_58cd_p38.htm

With regard to the B-25, one of our customers has actually put a couple of 90SP engines in his plane and it looks fantastic. He has cut down 15.75x13 3-bladed APC props to 15x13 and you can view this plane on www.rcvengines.com/gallery_90sp_b25.htm

I hope this information helps
If you have any more questions, please don't hesitate to contact me.

Best regards
Laurenne

us1hydro

My Feedback: (23)

Thanks for the response, any way to contact the B-25 builder? I'd like to find out how he made those props! They look GREAT! I have a 90SP in my hands now and a 60SP on the way. Props are a real problem though. Have you considered asking one of the prop manufacturers to make props for your engines? Since the primary use of these engines will be with scale planes it would be nice to have props available that mimic the look of the "real thing". The APC's are good props but lack the "look" of the Hamilton Standard!

RCV Engines

Hi

With regard to contacting the B-25 builder, we do not give out email addresses. However if you want to write an email for him, I can forward it on - use my email address [email protected]

With regard to propellers, I understand the problems. APC do a good range of propellers, however all the ones that are suitable for our SP series engines are schimitar shape, which is not always what you want for scale. I did approach Master Airscrew at one point, however nothing ever came of this.
Other manufacturers which may be of use are graupner, bolly and (for wooden propellers) zinger.

I hope this helps.
Best regards
Laurenne

us1hydro

My Feedback: (23)

I sent you an email to forward to Charlee. Thanks!
I've been trying to find some Graupner 3 blades. Their web site either dosn't show the big 3 blades or I just haven't been able to find them. Their website is a bit difficult to navigate. All I can find is electric props. I know they make bigger props, I have some of them. I'll look around at some of the premium prop makers to see what I can find. If all else fails there is a guy in Milford that makes custom props. Pricy ($60) but very nice.
Just a thought - the prop makers would probably be more receptive to making props suited for your engines if they were sure of selling enough of them to justify the set-up cost. If RCV were to offer to buy a reasonable quantity of 3 & 4 blade props they would most likely be willing to make them. RCV could, in turn, offer them for sale to their customers. Once the manufacturers are set up to make them they would soon be available at the normal outlets. I would think this would be in the best interest of all concerned.
RCV would probably sell more engines. The lack of available props is, frankly, a deal breaker. What good is an engine if you can't get a prop? Since the whole purpose of spending the extra money is to enhance the scale appearance of the model, if you can't match it with a scale looking prop the purpose is defeated - you might as well stick with a conventional engine! Additionally, warranty work and the companies reputation for durability would probably be improved. I just got a second-hand RCV60SP that came with the prop the guy was using for break in. It's not the recomended pitch but the heaviest pitch commonly available. I suspect that a good many RCV buyers are doing that. Under pitched props will result in higher revs and probably premature engine failure. That's bad news for everyone!

The prop maker would sell more props since they would be the ONLY manufacturer of props suited to this purpose.
The modeler, your customer, would gain by having engine/prop combos that enhance the scale appearance of their model.
Just a little something for the suggestion box.........
Larry

Aluminum Overcast

I have a really beautiful four blade scale outline prop for my KMP Spitfire made by solo props. They will make any size or shape prop for your application and hold the blades with a hub which you can dial in your desired pitch. not exactly inexpensive but very scale and adjustable for peak rpm.