Big Al-RCU

Hi guys, I’m putting together a Tower order and want to include some props for a Norvel .074 (which I don’t have in hand yet, but expecting in the mail soon). What props are you using? I know this has been covered previously in numerous threads, but at the moment, I and the RCM search engine are at loggerheads ($*@*#).
Thanks in advance,
Al Lenz

SGC

Al,
The concensis is the Norvel 074 performs best on a 7x3" or a 7x3" prop
Stewart

Big Al-RCU

Thanks Stewart, I wonder what is prefered for a sport model? APC, MAS. etc

digital_trucker

Graupner (everyone seems to overlook 'em). I find they pull better than any others I've tried, including the ever-popular APC (they don't try to turn your fingers into potato wedgies so easily either). Plus, they don't break very easily. I have yet to break a single one.

Larry Driskill

My better results were with the MAS.

GrahamC

I like the Graupner props as well. They are a bit heavier than the MAS or APC but also a bit tougher and work just as well. The Graupner 5x2 is just the thing for a Cox Pee Wee 020.

Generally however, the reason the Graupners are not as popular is that not every local hobby shop carries them and when they do they tend to be more expensive than the MAS or APC's.

cheers, Graham

digital_trucker

I order a wad of them at a time from Hobby Lobby.

eroc144

My Feedback: (1)

I turn roughly 1000 rpm more with the 7x3 APC than I do with the 7x3 MAS. YMMV.

EG

mtntopgeo

My Feedback: (12)

A lot depends on what plane you intend to bolt your Norvel to. Back when the .074s were popular, I recall that most folks were using 7x3 props. A few years ago I spent most of one summer in a ".074 Norvel vs. .09 Enya" project. Plane was a Mini Super Sportster, & a profile varient of the same; also used a 48" w.s. pink foam, home-built. Tried a load of props with each combination. Even though most would disagree with me, I found that if you're needing to use a 7x3 or 7x4 prop the .09 was much better in the air. Both engines were nearly at the same RPM on the test stand, but at 17,100 RPMs the Norvel really isn't in it's horsepower range. With a 6x4 MAS, the Enya was better on the bench, but the norvel (being closer to it's H.P. peak) would unload more, & was better in the air.Took the Profile out several times, with this combo, & thought that I had found the ideal set-up. One day, after cleaning out a plugged NVA on the Norvel, (got to start using a filter) I put the profile in the air with the needle a tad too rich. Rather than bringing it back down, I thought that I'd take it high, & put it in a steep dive to "clean 'er out". About 2 seconds into the dive, the sound from the Norvel increased so much that I thought that the muffler had fallen off. In reality, the engine had finally gotten on step, & was enjoying it's run in the higher RPM range, resulting in a very big leap in performance. What a blast that combo (Norvel .074, 33% nitro, MAS 6x4, MSS profile) was/is. I really think that improved performance could be had by using a 5.5x4 prop, but like a lot of others, I'm trying not to run my Norvel too close to the edge. I have not run the APC props enough to comment on the performance. My "flying field" is a cow pasture, &, without a langing gear, I was breaking the APCs all too regularly. Long-winded reply, but just trying to get the point across that you're gonna have to experiment some to get that "perfect" combo. ............ George K.

SST

My Feedback: (2)

I have found the Cox 7X3.5" props to be the best thrust props for sport models, but since they're so hard to find, I understand the Graupner 7X3" are nearly as good. I have an .074 with the Cox prop flying a 60" span Sig Ninja at 38oz, and able to loop it from level flight.

Silvaire

My Feedback: (50)

Good post George,

The choice of a "best" prop is very much a matter of engine, airframe and mission.

Arlen