Catto static rpm at full throttle?

rightrudder · #1 12-24-2015, 07:40 PM

I've got an IO-320 D1A (160 hp) with a Catto 70x70 2-blade prop. What static rpm should I see at full throttle?

I just recently ran the engine for the first time and did a few seconds at full throttle. I only saw 1510 on the tach, but I suspect a tach calibration issue, as the engine was pre-run in a test cell at Lycoming.

grubbat · #2 12-24-2015, 09:50 PM

I would think that you should see anywhere between 2100 to 2250 static.

AX-O · #3 12-24-2015, 10:04 PM

I just talked to him a few days ago. He wants above 2200 rpms. 2250 preferd.

I was at 2100 and he said it was too low. His is narrowing the prop cord and increasing the pitch to get the right combo.

Check your tach and throtle cable range/movement.

Dbro172 · #4 12-25-2015, 02:27 AM

I was right at 2200 with that prop, maybe a touch more

rightrudder · #5 12-25-2015, 07:43 PM

Thanks, guys. After delving deeper into my EFIS manual, it looks like the tach pulse code may be off in the EIS, giving the erroneous readings. Will check tomorrow, and report the rpm. Merry Christmas!

rightrudder · #6 12-26-2015, 07:21 PM

Success! Tach is now calibrated correctly, and I'm seeing 2270 rpm at WOT.

AX-O · #7 12-26-2015, 07:45 PM

That is better.

breister · #8 01-17-2016, 04:26 PM

Depending upon your mission profile and hoped for top speed 2,200 might be fine.

If you level out in cruise at or above 8,500' and have to pull the throttle back to prevent overspeed, you have room to increase the pitch a bit (if you want) at the expense of a little climb performance. You are more likely to have that issue (opportunity?) with electronic ignition, which has more impact on hp at altitude than it does at T/O.

Fearless · #9 05-20-2017, 02:52 PM

I was doing a run up on my engine this morning in preparation for my first flight and was only getting 2160 reading on both mags with my two blade fixed pitch Catto prop for my O-320 160 hp engine at full throttle. So I won't see 2600/2700 rpm on the ground? I thought I had an issue with engine and throttle when it wouldn't go any further.

AX-O · #10 05-20-2017, 03:45 PM

Quote:

Originally Posted by Fearless

I was doing a run up on my engine this morning in preparation for my first flight and was only getting 2160 reading on both mags with my two blade fixed pitch Catto prop for my O-320 160 hp engine at full throttle. So I won't see 2600/2700 rpm on the ground? I thought I had an issue with engine and throttle when it wouldn't go any further.

If you see 2700 on the ground, you will probably see over 3400 in flight all in.

2160 on the ground is good to go.