Catto Prop Static RPM

[David-aviator]

Greetings,

I am one notch closer to flying again in that the Lycoming came to life today after a preheat to accommodate the 50 weight mineral oil with an OAT of 18F. The engine is running fine and I did the Lycoming first start procedure as per their service instructions. The only squak is no oil temp so that will have to be run down. It never came off of 59F.

On the full power run, I took it down the runway twice. Static rpm is 2150 and quickly increased to 2250 as speed increases. Those of you with a Catto prop, is that about normal? Acceleration seems to pick up quickly with increasing rpm. It definitely is no slouch.

More freezing rain coming in tomorrow so first flight will have to wait.

[Mel]

2150 static is pretty low. I get 2250-2300.
Of course a new engine is going to be a little tighter so that may be the difference.
Does Lycoming recommend 50 wt oil. I would expect 30 or 40 wt for break in, especially in low temperatures.
You are not likely to get "hot" oil on the ground. The engine is simply not loaded enough.

[painless]

David:

Your numbers are right in line with mine. O320 E2D 150hp.

Congrats on getting back airborne. I have followed your progress/setbacks with your Eggenfellner Subie over the years. Sorry all that didn't work out for you. Hopfully all that is behind you and you can enjoy your airplane more.


Best of Luck on initial flights!


Regards,

[videobobk]

I would say you are in the ballpark. I only hit 2250 on climb out (not cruise climb) and I would think 2150 is about right with cold oil, etc. You will love the prop! At 2250 I usually see 1200-1800 fpm, depending on load and temp. I have the 160 engine but the prop probably has a bit more pitch.

Bob Kelly

[David-aviator]

Thanks for the info, guys.

With the temps what they are, I should be using 30 weight oil. The local pilot supply shop had the 50 weight mineral oil in stock about 2 months ago when it was warm - so I bought it - not thinking about this record cold air.

I need to check the oil temp wiring and drop the probe into hot water to see if it works. You would think that if the CHT's get up to 300F during a ground test run, the oil temp would at least come off the peg. Sandy at GRT says it may not be hooked up properly, like maybe I did not connect the ground wire.

[roadrunner20]

Originally Posted by David-aviator

Greetings,

I am one notch closer to flying again in that the Lycoming came to life today after a preheat to accommodate the 50 weight mineral oil with an OAT of 18F. The engine is running fine and I did the Lycoming first start procedure as per their service instructions. The only squak is no oil temp so that will have to be run down. It never came off of 59F.

On the full power run, I took it down the runway twice. Static rpm is 2150 and quickly increased to 2250 as speed increases. Those of you with a Catto prop, is that about normal? Acceleration seems to pick up quickly with increasing rpm. It definitely is no slouch.

More freezing rain coming in tomorrow so first flight will have to wait.

David,
Those numbers sound right to me.
Craig likes to see static+500 for full range.

[pierre smith]

....to what I see but like Mel, I get 2200 static with a warmed engine. If you'll climb with the horizon in view at 135-150 MPH, your revs will climb closer to 2400-2500, making more horsepower and a better climb.

BTW, my buddy just re-weighed his -7 after the Eggenfellner 4 cylinder removal and with the new IO-360 Lyc is 110# lighter and the CG is moved rearward as well, closer to optimal.

BTW.....anyone need/want a 200 hour firewall forward, Gen 3 PSRU, 4 cyl EGG for half price or less? It's located in Sandersville, Ga (OKZ).

Regards,

[N131RV]

Originally Posted by David-aviator

Greetings,



On the full power run, I took it down the runway twice. Static rpm is 2150 and quickly increased to 2250 as speed increases. Those of you with a Catto prop, is that about normal? Acceleration seems to pick up quickly with increasing rpm. It definitely is no slouch.

More freezing rain coming in tomorrow so first flight will have to wait.

I have a CATTO on my Long-EZ, 160HP. While the engine was breaking in I got very similar numbers (about 2200-2250) for static RPM. The rings have set and the engine is now turning almost 100 RPM more static. You really want that extra 100 RPM, it makes quite a difference.

I climb out at 150 MPH indicated, 2400 RPM. Cruise is 195 indicated, between 2750 and 2800 RPM.

[David-aviator]

Originally Posted by David-aviator

.....The only squawk is no oil temp so that will have to be run down. It never came off of 59F.

Well, after running a new ground wire, checking the wire from EIS pin 15, plus the crimp connections, changing oil from SAE 50 to 30, and generally wasting an enormous amount of time, it was proven today the screw in sensor is no good.

I dropped it into a coffee can of very hot water and the indicator finally came off of 59F - all the way up to 66F. Meanwhile a digital cooking thermometer indicated the water temp was 182F. Next step was to rig up a left over liquid cooling sensor from the Subaru and try it. By now the water had cooled to 142F and big fat surprise, EIS indicated 147F with it!!

Next I measured resistance across the Subaru sensor (actually a VDO 702), it was 500-600 ohms. The Lycoming sensor measure in access of 20k ohms. The way these things work is the resistance changes with temperature and the indicator box deciphers this change into a number which is reported as a temperature.

Conclusion, I either have a wrong sensor or it is not right.

Message has been sent to GRT and maybe I can move on to something else, like finish the condition inspection, reactivate the flight insurance, move back to phase one, have a couple guys look at things, and get this thing in the air. I need to let it rip for a while to seat the rings.