What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

static rpm with 3 bladed prop

D

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
Click to expand...

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.
 
Last edited:
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).
 
You must log in or register to reply here.
Back
Top