O320 with C/S prop vs. IO360 with Sensenich

I have a RV6A with a O320 and Sensenich metal prop and unhappy with takeoff and climb performance. Looken at either putting a Hartzell C/S on the O320 or replaceing engine with an IO360 with Sensenich metal prop. Which sanerio is going to give me better preformance?

Any inputs would be greatly appreciated
Thanks Bryce McClaren

The C/S prop will give you more overall performance than the 180 hp. The C/S will give you considerably more take-off performance. The higher hp with F/P will help, but not as much.
First, make sure that your engine will accept a hydraulic C/S prop. Just a hollow crank is not enough.

It's hard to beat C/S

I had a couple different fixed pitch props on my 8. IO360A1B 200hp gave me pretty good performance with the fixed but not up to expectations with that engine.
I converted to a WW200RV C/S and the difference is dramatic. Take off and climb vastly improved and a quieter, smoother cruise for me.
If you can afford the weight and a bit of hassle, the transition, I think, is well worth it.

What about Cruse?

Which senario is going to give me a better cruse speed the IO360 has a solid crank so a C/S prop is out of the question there. What about additional weight
Bryce

Matched to the right prop, the 180 hp engine will give you more cruise performance. The C/S + O-320 will give you better takeoff and climb perfomance, which was where the thread began...

This choice comes up from time to time and for my money it's an easy decision... the O-320 with the c/s is a far more flexible package than the O-360 with the f/p. This may not be true for other slower aircraft, but with the speed envelope of the RV (50-220 mph), and when all phases of flight are considered, the c/s provides far more benefit and flexibility.

Consider just two phases, descents and approach to landing. With a c/s you just point the nose down and leave the power, no worries about shock cooling or overspeeding the engine. On approach with a c/s you can drop it in over trees and other obstacles in a way you can't even think about with a f/p.

FWIW,

Engine CS prop compatible

Mel is right of course. Not all hollow crank engines will accept a CS prop. The answer is on the TC data sheet for your engine model.

If your present O-320 WILL accept a CS prop, then do that and be done with it. 20 more hp is nice, but is it worth the $$ and trouble? If you have a heavier RV6, perhaps? Note, more than 180hp is NOT recommended by Vans for RV6.

If present engine incompatible, next cheapest route is mid time CS prop compat engine plus CS prop. BTW, I know 2 ECI O-360 kit engine operators that like them, and they cost little more than a good mid time Lyc.

I've done the FP to CS prop drill on an O-320D2B equipped RV6 and speak fm experience.

I also now have a 180hp, CS prop, RV6 that is heavier than my last one, which had a 160hp, CS prop. Performance difference, not much.

I've also thought about this for somewhat related reasons.

The plane is a flying RV-6A with an O320-D1A (160HP) and a Sensenich FP 70CM()S16-0-79 with a metal spinner. This prop is the one with the 2600 rpm red line. Currently if I come in loaded at minimum fuel, the landing CG is right at the aft limit. So to get better performace all around, I switch to a Hartzel C2YL-1BF/F7663-4 and whatever-is-best governor and a fiberglass spinner.

Just a rough look at the numbers says is about +8 lbs at the prop (which I feel I can get off the gross weight of the plane elsewhere), and XX lbs at the rear of the engine, and maybe performamce overall is better and landing CG is more under control.

Does anyone have good weight data for the various CS governors?

I haven't done the homework but an MT electric prop may work without the expense and trouble of having to change your current engine.

Peter

C/S vs. F/P on O-320

IF you have an O-320 that will not accept a Hartzell C/S Prop consider the following verses both an engine and prop change:

I installed an Avia V 503AP prop on my RV-6A. When I bought such RV, it had a Lycoming O-320 150HP solid crankshaft with only 254 hours on a certified engine overhaul. I did not feel that changing it to a 160HP or 180 HP with a hollow crankshaft so I could put on a Hartzell prop was not an option.

With the wood prop on my RV-6A when I bought it, at gross weight I needed about 2200 feet to get off the ground and it had really bad climb performance (KLBB 3200 MSL). At 6000 feet I would have to level off and after reaching cruise speed put it back into a climb for 500-1000 feet and then start all over again to climb up to 10000 feet which seemed to be about the max altitude with the wood prop.

In addition in order to land I had to make a really flat approach, add flaps and drag the airplane on the runway with power in order to land in less than 1000 feet.

After I put on the Avia prop my takeoff distance at gross weight was about 800 feet and I could turn a short base to final from 1000 feet, cut power and the Avia prop would kill off my airspeed and I could dead stick it onto the runway stopping in about 600-700 feet.

My climb at 95MPH with the Avia prop at gross weight was in the 1400-2000 fpm range depending on time of year.

In addition, the Avia prop was wonderful doing loops. You never had to touch the throttle coming out of the top because the Avia prop acted like an air brake and the speed never was a problem coming out the bottom back to level flight.

One of the neatest things about the Avia prop was watching the face of a pilot riding right seat when leveling off from climb to cruise he would see the spinner come to a complete stop and then reverse direction, which occurs as the prop automatically changes pitch.

I ordered my Avia prop directly from the Factory in the Czech Republic and they shipped it via British Airways/American Airlines directly to me in Lubbock and it was just a matter of bolting it on. I did have to do a number of flights and ground adjustments to the Avia prop to get it set just where I wanted it to be for my flight operations. There is a ground adjustment which allows you to adjust for more or less pitch on takeoff depending on whether you want better climb or better cruise setup.

I did have to do a FAA revision and get a new airworthiness certificate and put it back into stage 1 flight testing with the prop change. Since I did not have a repairman certificate for the RV-6A a local A&P signed off the paperwork and got the local FAA office to sign off the prop conversion.
The AVIA main web site page is at

http://www.aviapropeller.com/

If you click on products and then item #1 it will show you a page that has the prop listed and indicates it is for both the C-172 and the RV-6. Click on the "Technical Description" and a Pop Up page will appear with the info.

If you have a pop up stopper on your computer you will have to disable in order to see the pop up page.

Although it took a long time to get my Avia Prop actually shipped, I was pleased with the factory delivery, shipped via British Airways and American Airlines directly to Lubbock. You can only get shipment to an airport with a customs office. The customs fee charged was only $20.00 since it was for personal use.

The install of the prop was a little bit of a pain because of all the trial and error adjustment to final get the prop set where I wanted it. There is basically a range of prop pitch settings and you have to ground adjust to get it where you want it. If you adjust for maximum climb performance you will lose a little bit on the cruise performance and vice versa. On the cruise side I averaged about 185 mph cruise. Static run up was about 2200 rpm but as soon as the takeoff roll started it would quikly climb to about 2500 RPM.

In contrast with the Bernie Warnke wood prop I had about a 2500 foot take off roll, a climb rate of about 500 feet per minute and a cruise speed of around 192 mph. Static run up and take off roll it was only pulling about 2100 rpm.

The one real big drawback of the Avia prop is that if you ever have an engine failure you don't have a very good glide rate because the prop acts as an airbrake and unlike the Hartzell you can't change the pitch. With an engine failure it really is time to hunt for a spot to land.

The same basic Avia prop is installed on one of the Zlin Aerobatic airplanes. The difference is that the Zlin prop turns the opposite direction because of the engine on the Zlin.

Would I do it again? YES!! The fun and performance difference took a
poorly performing RV-6A to wonderful heights.