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dan carley

Well Known Member
i have a 3 bladed catto prop on my rv4 and only getting about 3000 rpm on my static run up. is this normal? seems a little low. the rpm at full throttle is 2700 rpm which is about right.

thank you
dan carley
 
dan carley said:
i have a 3 bladed catto prop on my rv4 and only getting about 3000 rpm on my static run up. is this normal? seems a little low. the rpm at full throttle is 2700 rpm which is about right.

thank you
dan carley
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3000 rpm on static run-up makes no sense at all. You should never be able to get anywhere near 3000 rpm on a Lycoming with a fixed-pitch propeller at static run-up.
 
Dan, did you do a search on the forum? I have talked about this a few times.
 
I have a Cattto 3 blade and an O-360. I get only about 2300-2400 static. I don't get up do 2500 until about 160 knots. I don't get close to 2700 unless I am high altitude (>5000MSL) and high speed (>170MPH IAS). I routinely fly at 2500 RPM and 180 MPH IAS.

Interestingly, I have a MP gauge, and have to fly around "under square" to stay below 2500 RPM at hi speed hi altitude, so I know I am flying around at maybe 60% power.
 
Seems like I remember Craig saying he likes to see static + 500 on his props.
That was several years ago but with your 2300, it seems about right.
Try giving Craig a call to confirm.
 
Catto

My O-320 RV-4 with three blade Catto gets 2200 static and 2700 WOT at 8500 altitude speed test.

Jim
N444JT
 
About the same here. 150hp RV6. Catto 3 blade. About 2200 static, 2700 WOT at 8500ft. 192mph. Typical cruise setup is 2300rpm, 22" manifold pressure and 155mph.
 
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max RPM

I know the Cattos are rated for >2700 RPM but that is the limit for my Lycoming. Does anybody exceed that in Lycomings? I would not do so. I prefer to fly around <2500 RPM. But are we doing any harm by flying at 2600 or 2700, especially WOT at altitude? I have heard that the O-360 cannot really make >75% power above 5000 MSL, so it may be ok for the engine to be operated at any RPM at or above 5000 MSL (except of course respect 2700 limit).
 
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