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Engine basics => Engine set up tips => Topic started by: Allen Eshleman on July 06, 2020, 04:06:45 PM

Title: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Allen Eshleman on July 06, 2020, 04:06:45 PM: I know that a two blade 9/4 is the standard place to start with LA 25's, FP25's and Magnum GP 25"s. I am finding a problem with Landing Gear not being long enough and so the ends get clipped off when taking off. It happens more when using my stooge.

Has anyone tried 3 blad props with these engines and if so, what worked?
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: phil c on July 06, 2020, 04:29:51 PM: If you can find a 3 blade 8/4 prop it should work pretty well.
Saw APC has a 9/4 4 blade, probably a bit much.
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Brett Buck on July 06, 2020, 07:29:37 PM: Quote from: Allen Eshleman on July 06, 2020, 04:06:45 PM
I know that a two blade 9/4 is the standard place to start with LA 25's, FP25's and Magnum GP 25"s. I am finding a problem with Landing Gear not being long enough and so the ends get clipped off when taking off. It happens more when using my stooge.

Has anyone tried 3 blad props with these engines and if so, what worked?

One potentially good choice, if you can find one, is a Tornado 10-4 3-blade. I have seen those used on even 20FPs, and it more-or-less worked. It works very well on a 25FP and probably pretty good on a 25LA.

Brett
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Air Ministry . on July 06, 2020, 08:45:28 PM: Were 8 x 6 Tornado 3 blade . If theyre like the 10 x 6 , theyll be about a 5 . Theres even 7 x 6s & maybe ? a 8 x 4 . The FSR 25 was a bit limp on a 10 x 4 3 Bl . Equivilent of a 11 x 4 maybe .

Look up ' Grish - Tornado . ' 436 hobbies in NZ had them . :P Found theres a flight differance between the black & stiff silver , too . The BLACK suits the G - 51 . Silver the 21/46 . ???
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Allen Eshleman on July 07, 2020, 05:26:28 AM: I found a Master Airscrew 8x6. Has anyone ever tried it with a 25?
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Trostle on July 07, 2020, 02:50:12 PM: Quote from: Brett Buck on July 06, 2020, 07:29:37 PM
One potentially good choice, if you can find one, is a Tornado 10-4 3-blade. I have seen those used on even 20FPs, and it more-or-less worked. It works very well on a 25FP and probably pretty good on a 25LA.

Brett

Dick Mathis' original Chizler in colored tissue/clear dope finish used a Tornado 10-4 prop cut down some. That was with a Fox .35. He placed 2nd with it at the 67 Nats behind Bart Klapinski.

I have no idea if he changed the pitch, which you could do with those Tornado gray props.

Keith
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Dennis Toth on July 07, 2020, 04:57:13 PM: Keith,
I assume that Dick would have needed to run the Fox in pretty much a flat out 2 cycle mode maybe one of the first to run low pitch - high rpm.

Best, DennisT
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Allen Eshleman on July 08, 2020, 05:18:15 AM: I see that Master Air Screw has a 7/4 also. I haven't decided to buy either one yet but the 8/6 and 7/4 would be interesting experiments.
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Dennis Toth on July 08, 2020, 08:28:54 AM: Allen,
I have used the Master Airscrew 3 blades and one thing I found was they are 1" pitch low for the marked pitch. I wound up using a 9x7 and found it saw about the same as a 6" pitch.

Best, DennisT
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Dave Moritz on July 08, 2020, 09:30:08 AM: Allen:

Larger wheels an option?

Dave Mo...
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Allen Eshleman on July 09, 2020, 02:38:59 PM: "Larger Wheels"

Great idea!
Title: Re: 3 blade props for LA 25, FP 25, Magnum GP25
Post by: Allen Eshleman on July 09, 2020, 02:43:19 PM: Btw, I ordered 2 8/6 MAS 3 bladers, 1 7/4 and 1 10/5. My idea is to try the 8/6 on my 25's. I am not sure about trying the 7/4 on a 25. The 10/5, I may try on my LA 40, and some plane with my Brodak 40. The B-40 is on a twisted wing Magician and I don't think I will try it again. I don't know if the 10/5 would be too small for an LA 46. I just ordered them today. Looks like an almost two week wait.