200HP IO-360 question

I've got a 10:1 CR IO-360-A1A 200HP attached to a Catto prop. I'd be really keen to hear from others with the same or similar setup on their fuel flows and static RPM on take-off and other parameters so I can figure out what I expect to be normal.

I suspect my fuel servo is running rich on take-off so I was talking to the people at Bendix about the setup of the RSA-5 fuel servo and they said that the EGT change from full rich to peak EGT at take-off power should be around 150F. Has anyone ever leaned out on take-off to check?

What's the word on high MP and low RPM such as take-off and detonation issues with these setups?

Perhaps I should do a full power run-up and see what I get as I lean.

Hi Anthony

My -6A had an O-360, carbed, with a three-bladed Catto, optimized for cruise, since Craig had asked if I objected to run at 2700 revs or so. Our prop only turned 2200 RPM on initial WOT at 325' above sea level and accelerated to 2350 or so by liftoff.

I usually climbed it at 140 MPH or faster and had 2400+ RPM...more revs, more horsepower, right? Even 160 MPH gave over 1,000 FPM climb and we ended up with 201 TAS at 7,500' and 2750 RPMs, exceeding Van's numbers, which Craig said we would with a strong engine.

We flew it this way for 500 hours and I never felt or saw any evidence of detonation, running 100LL avgas.

Best,

I will have to look again on the next flight. I don't quite have your setup since I have a constant speed prop. I do have the 10 to 1 pistons with FI. I see if my memory is correct 17.5 to 18 GPH at 2700 RPM.

George

I have the Catto 3blade 68x74, IO360-A1B6

I also feel the RSA5 runs too rich on take off.
I have 8.7:1 compression and 1 pmag. 10:1 will reduce the detonation margin, I got my engine with 8.7:1, but would probably move to 10:1 if I had to change pistons.

I typically take off full rich but lean a bit shortly after take off.

On a 20F day at 4500 I was running 2930 rpm. I sent the prop back to Craig to get re-pitched to 68x75.

I do that with a bit of trepidation. The plane is in paint and I should get the prop back today. It will be a while before I can report on the results.

NDrv8r said:

I have the Catto 3blade 68x74, IO360-A1B6

I also feel the RSA5 runs too rich on take off.
I have 8.7:1 compression and 1 pmag. 10:1 will reduce the detonation margin, I got my engine with 8.7:1, but would probably move to 10:1 if I had to change pistons.

I typically take off full rich but lean a bit shortly after take off.

On a 20F day at 4500 I was running 2930 rpm. I sent the prop back to Craig to get re-pitched to 68x75.

I do that with a bit of trepidation. The plane is in paint and I should get the prop back today. It will be a while before I can report on the results.

Click to expand...

What static RPM are getting?

What makes you think you are too rich at take-off?

Did you always have one pmag? I'm running 2 slicks and I wonder what changes I'd expect after switching.

One of my friends said that installing a pmag was the biggest factor making his engine run smoother.

Australia;

sorry, didn't have the static rpm recorded, seemed like 2250 or so.

I think it was too rich because I could get higher rpm in the climb...how much? I'm gonna do more testing when I get out of paint.

I've always had one pmag. the difference in smoothness is incredible. At altitude, I can just lean till the power just falls off and eventually quits. On the mag check the motor just sound like it is labouring. rpm drop is fine. In fairness, the pmag is all top plugs and the bendix is all bottom plugs.

On the 182RG i had, anything less than 12gph ran really rough.

Install the Pmag, you won't be sorry. I still kind of like the idea of a std mag backup, but if I got ahold of another mag gear, I might be tempted to put another pmag on (a new mag gear is $$$), although I wouldn't expect any better performance with both pmags.

I just got the prop back from Catto. The nickel leading edges look great. I'll report back on the performance, but ND winter weather may hold me down. I know it is best to check only one thing at a time, but I am tempted to install a Rod Bower ram air while cold weather keeps me on the ground.

Chicking full rich mixture.

On an Injected engine, set 24 square at around 3500 ft. Slowly lean the mixture until one cylinder peaks in EGT. Record that EGT number. Put the mixture full rich. When the EGT stabilizes, record the EGT number for the cylinder that you recorded the peak value for. Take the difference in the two values. It should be between 180 and 220 degrees F.

Do not lean the engine in this manner it your MAP is above 24".

Don

Ant CB said:

I've got a 10:1 CR IO-360-A1A 200HP attached to a Catto prop. I'd be really keen to hear from others with the same or similar setup on their fuel flows and static RPM on take-off and other parameters so I can figure out what I expect to be normal.

I suspect my fuel servo is running rich on take-off so I was talking to the people at Bendix about the setup of the RSA-5 fuel servo and they said that the EGT change from full rich to peak EGT at take-off power should be around 150F. Has anyone ever leaned out on take-off to check?

What's the word on high MP and low RPM such as take-off and detonation issues with these setups?

Perhaps I should do a full power run-up and see what I get as I lean.

Click to expand...

I had that exact set-up in my last aircraft (200 lyc and 3 blade Catto in a Velocity), even the 10 to 1. 2200 static and I would get around 2850 at higher altitudes. There was a wider dispersion on the EGTs, closer to 200 but never any detonation issues or problems. Lindbergh had proven the over square worry to be a myth a long time ago. You're only at about a spread of 6 to 7 (28+ mp and 2200 rpm) for a few seconds, as you're rolling the rpm starts catching up and you're only + 4 to 5 at takeoff and plus 4 in the climb. Even folks that don't like oversquare ops agree that plus 4 for cruise is acceptable.
I currently have Pierre's plane and it still runs as he stated--smooth, fast and no issues. It's got standard pistons so I've got some flex in octane requirements. The Velocity had 10 to 1s though and I did many full power climbs to altitude with no detonation.

FPTO Data

In my IO360 w/ 10:1 pistons and AFP injection, I get 18.5 to 19.0 GPH with around 1300 EGTs on a Full Power Take Off. 29.5 MAP/ 2700 RPM CS prop

Flyrod said:

In my IO360 w/ 10:1 pistons and AFP injection, I get 18.5 to 19.0 GPH with around 1300 EGTs on a Full Power Take Off. 29.5 MAP/ 2700 RPM CS prop

Click to expand...

I have this setup with C/S prop except I have a bendix injector. My numbers are the same except I'm not making 29.5" though (or burning 18.5 gph), I 'm more like 26.6 with 16.5 gph. I may need to do some research on this. My snorkel might be the issue, I had to modify it to get it to fit with my B&C starter.

panhandler1956 said:

I have this setup with C/S prop except I have a bendix injector. My numbers are the same except I'm not making 29.5" though (or burning 18.5 gph), I 'm more like 26.6 with 16.5 gph. I may need to do some research on this. My snorkel might be the issue, I had to modify it to get it to fit with my B&C starter.

Click to expand...

I rechecked my engine from the other post I made. I am seeing 19 GPH at 2700 RPM on takeoffs from a elevation of 800 feet. 10 to 1 pistons ECI IO360 with FI.

George

200 hp IO360

In my RV6 I am running an HIO-360-C1A behind a Catto prop. I have an RSA5 fuel control and dual P mags (and wouldn’t go any other way) No MP gauge (Sorry, suppose I should install one)
I have just completed 3 hours of testing so fuel economy and performance is yet to come however while flying to the test area I have noted Cyl temp 350° oil temp 230°@2450 RPM 155knots TAS at 2000 ftDA 28 litres Hour fuel flow 1300 EG T I have also tried another check at 2250 RPM this gave me 24 litres/ hour and 136 Knots TAS 1100 EGT These are off the dials so could change when I get to do the economy runs.
My static RPM is 2050 and I think I maintain this until take off around 65knots and straight into my climb.(will try to look more closely next take off) But if I climb at 75knots (no over temp of cylinders or oil it only goes up to 2150 however as soon as I level out and speed increases the RPM will increase to 2700(I throttle back at this RPM to maintain 2700) at this setting I will reach VNE 182KnotsTAS fairly quickly.
Hope these help you, if you want any more just let me know

Regards