Cruise rpm

[RIVERFOX]

What do most of you with 80hp 912 use for a standard max cruise RPM?

[cap01]

with the pitch i have set in the prop , im a little shy at takeoff , 4900 rpm . at cruise i usually 5200-5300 burning 4.3-4.5 gph . i dont have the taper tips but will probably take the prop off this winter and get it shaved . so ill see what difference that will make ?

[DesertFox4]

5200 - 5500. 5500 when extra cooling was needed on a hot desert day.

[HighWing]

Standard max cruise on the 912 UL is 5500 rpm. I know a lot of guys that shy away from 5500 and some who will cruise higher. I flew at least above 5000 as I have heard that the gear box takes more load at lower rpms. 5500 max cruise is spelled out in the Operators Manual, but I would often be flying with friends and we would throttle back to the slowest airplane. When solo and wanting to get somewhere, 5500 was the norm.

Lowell

[cap01]

yep lowell , ive read that your not doing the engine any favors by running her slow . shes made to run all the time at 5500 .

[Av8r3400]

At my current pitch (tapered Warp 3-blade, 912UL 80 hp) I cruse at:

~5400 for 105 mph @ 3.25 GPH (Verified on my trip to S-n-F this spring)
~5200 for 100 mph
~4800 for 90-95 mph
~4500 for 80-85 mph

[cap01]

larry , curious as to what you get for a static rpm ? my rpms and speeds arent too far off from you but im burning a bunch more gas .

[kitfox2009]

I have just recently installed a 70 inch IVO IFA with Patriot blades on my Model 5 Vixen 80 HP 912UL. At 5500 RPM it is indicating 118 MPH!!! I only have 11 hours on it so I am not sure if this is accurate or not. Anyway it is a huge improvement to my old prop.
I have not installed the limiting washers so I have to be careful on takeoff not to exceed 5800.
Cheers

Don

[Av8r3400]

larry , curious as to what you get for a static rpm ? my rpms and speeds arent too far off from you but im burning a bunch more gas .

On take off I can get about 5200 rpm. I can redline the tach (just barely) in straight and level flight (110 mph plus).

(My crappy Matco brakes won't allow a full power run up! )

[RIVERFOX]

Larry, my rpm and speeds are just about the same but my take off rpm is only 4900. Do you have separate filters at each carb or do you have the older carb heat with the long tubes running from thealum. box up front?