[Public-List] Standard Prop Size and Pitch

[Mike Lehman]

Brian,
 
12" diameter is actually much better since on the A30 the prop is in an aperature. The experts will tell you that the prop diameter should not be more than 80% of the aperature opening. With a smaller prop there is less prop wash and less noise. Higher RPMs help to reduce carbon build up. An engine running at a low RPM under laod is often laboring because you are not high enough on the designed power curve. Tis laboring promotes carbon build up.Mike Lehman  ><((((º>`·.¸¸.·´¯`·.¸><((((º>`·.¸¸.·´¯`·.¸><((((º>  > Date: Thu, 22 May 2008 11:20:22 -0400> From: Bpalmer at DigitalArsenal.com> To: public-list at lists.alberg30.org> Subject: Re: [Public-List] Standard Prop Size and Pitch> > On L'Esprit, I've got an Atomic 4 with the 13x7 prop. The engine runs> strong and smooth, but when in gear, I can't rev higher than maybe> 1900RPMs. If I push the throttle higher, the engine doesn't go any faster.> I think it's just that the engine is working hard enough that it simply> can't spin the prop any faster under that load.> > It's not a problem, since I can motor along at 6 kts or so on flat water. I> hear people mentioning 2300RPMs... It would be nice to have this as reserve> power if I was motoring against the wind and chop or something. Do those of> you who also have A4s with the standard 13x7 2 blade find the same> limitation?> > On a side note, Towney mentioned before that he had his 13x7 prop turned> down to a 12x7 prop after getting a nick in it or something. He said the> engine ran like never before! He had the same problem I speak of, with the> RPMs never getting high enough to take advantage of ideal HP and torque> available at those higher RPMs. He said that once the prop was smaller it> felt like it was a better match for the A4.> > -Brian Palmer> _______________________________________________> These businesses support your Association:> http://www.alberg30.org/store/A30supporters.html> Please support them.> _______________________________________________> Public-List mailing list> Public-List at lists.alberg30.org> http://lists.alberg30.org/listinfo.cgi/public-list-alberg30.org
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