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Engine basics => Engine set up tips => Topic started by: Peter in Fairfax, VA on March 06, 2019, 12:06:32 PM
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One of the members of our club (Northern Virginia Control Line, NVCL) is interested in twins, especially creating a model of a P-38. We are considering Fox .15 power, with counter rotating props.
We have several loop bypass Fox .15s to work with, as well as a clockwise crankshaft.
On the prop side, we have Zinger 9x4P, 9x5P and 9x6P, as well as the same in tractor. We plane to cut down the 9" props as needed to obtain a decent RPM, using the tractor props for initial test stand runs, as we have them in greater quantity.
Thoughts?
thanks,
Peter
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I have been wanting to do this with a Sheeks Mosquito and a pair of LA.25s or FP-25s, but no one makes a left hand crankshaft for them and too cost prohibitive to make one or two for the project. If I could find a Fox left hand crank, which I'm pretty sure were made, I would substitute that. I've been looking for 20 years or so. Left hand cranks for the .15 will be just as impossible to find, since they probably never existed.
Type at you later,
Dan McEntee
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Peter,
You might take a look at the old magazine construction article by Lew McFarland of his P-38. It used two K&B .19s and three-line control. It may help you with design, sizing, and power choices. There are plans on-line. (American Modeler, Sept. 1966)
If it were me, and I had a reverse crank engine, I would put it in the outboard location to avoid adding to a single engine out torque problem unique to a control line airplane. So the top of the props would turn into each other. This is opposite of what the real plane did, except for the original prototype.
Good luck with your project!
Dave
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Dan,
I may have a reverse crank for a Fox .19 that I can part with, as well as some Fox .19s.
Peter
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Commissioner Fernandez is monitoring this thread very closely.
Brett
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Who is this mysterious commissioner?
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Who is this mysterious commissioner?
Commissioner Larry Fernandez, Maximum Leader and co-founder of the World Famous "Fox 15 Hurl". And a formidable competitor in The Hurl itself, tied with a certain unnamed Deputy Commissioner (self-appointed) with 4 Hurl World Championships.
Brett
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Dan,
I may have a reverse crank for a Fox .19 that I can part with, as well as some Fox .19s.
Peter
Hi Peter;
Just sent you a PM.
Thanks a lot,
Dan McEntee
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Commissioner Fernandez is monitoring this thread very closely.
Is there a plan afoot for an Austral hurl?
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Well, motorman, you have schooled me on motor terminology / semantics. I mean the Fox .15 which was likely introduced about 1960 as the Fox .15x and produced at least twenty years, not the more modern one with the Schnuerle (Schnürle) porting.
As mentioned below, the use of "loop" to refer to the older design is obsolete.
https://en.wikipedia.org/wiki/Schnuerle_porting#Loop_scavenging
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Hi Pete:
I have a Sterling P 38 with two Fox .15x engines for power. No problems!! They started first flip and were very vast on 7-6 props!!
Frank McCune
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Is there a plan afoot for an Austral hurl?
That is a very good topic, and one much on the agenda of the Hurl Committee. We had considered one for Perth a few years ago, but unfortunately could not find a sufficiently prestigious support event. We had even begun considering which of our antipodal comrades to induct as a Hurl Commissioner. As it turned out, both PJ and Rihannon met the high standards, so we had a real dilemma on our hands.
There are several vexing issues associated with this idea, particularly the tendency of the local gravity anomalies to suddenly shift during earthquakes, thus confounding the issue of computing the necessary site weighting factors. Of course, the permitted launch azimuth is the inverse of the same point in the northern hemisphere. Perth, again, is a nearly ideal site, being a mere thousand miles or so east-northeast of a true antipodal point from the canonical Hurl site in Vacaville, CA, simplifying the problem considerably. And if nothing else, Australia is the home of the "slouch hat" - as worn by Sgt. Sam Troy in Rat Patrol. Kismet indeed!
These issues are well within the capabilities of our greatest Hurl scholars so we hope to have some exciting announcements in the near future!
As always (and I am sure I speak for the Hurl Committee and Commissioner Fernandez himself), thanks for your interest in the international phenomenon of The Hurl!
Brett