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Catto static rpm at full throttle?

rightrudder

Well Known Member
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.
 
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.
 
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!
 
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.
 
So it can't make the full rpm on the ground?

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.
 
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.
 
Thanks Axel

Just trying to be vigilant on all the items before I commit to the air. Now I just need to find a day where the wind gods will be kind.
 
close.

You are very close with these numbers. Don't sweet 50-100 RPM's for now. I don't remember the recommendation from Lycon right now as it has been a long time. The figure I think is 2200 or 2300 plus or minus 50 RPM's by the book. You will need to fly your aircraft for a while and get used to it. Then the real place you want to fined is up at 7500" D-Alt., where you should be getting your rated max RPM for that engine with full power and leaned to best power.
With some engines that is 2650 others 2700 or 2750 as with the one we fly. If you are this close to these numbers now you will have plenty of time to look up the specs. After all you have the magic leaver in your hand to moderate this. I think the best article I have seen was in one of the old Tonnie Bingulas books on fixed pitch props and flat 4ers' . Look in the arcives under fixed pitch props, you may find that stuff in there somewhere.
Hope this helps, Yours, R.E.A. III #80888
 
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