360's, 540's and so on

[Neverquit]

There's lots of buzz lately about IO-540's pushing the back of Cozy's lately. We have Chris' sleek beast in the latest pages of SA and now Mark has posted Jannie Versfeld's presentation on the beautiful ZU-DAR o-540 Cozy MKIV. The cool sound that 540 makes is significantly more powerful sounding than the 360. Besides that, its faster than the 360 Cozy by about 20 knots.

 

Put side by side I'm torn between the 360 and 540. Unless I extended the passenger space it seems at this time the 360 with a CS prop is the ideal match for the Cozy. With fuel consumption a major issue these days it seems the 540 is at a disadvantage. But if you look at speed comparisons to GPH, there's a wide range of data.

 

I compared N540EZ to ZU-DAR and found a lot of similarities but the data was still unconclusive comparing TAS, IAS, altitude, etc.

[ZUCZZ]

I don't know about figures ... but when Jannie's plane (ZU-DAR) approaches or departs it leaves plain goosepimples ... you can hear that drone for miles ... nearest sound is tinnitis or heavy rock but loud!

[Cozy Girrrl]

The additional 50% for parts for maintanance and overhauls gives me goosepimples too, you'd hear me whine from miles away; something like tinnitis or loud rock and roll, only louder

...Chrissi

[Edge 513]

At 100-150 hours/year...I figure an overhaul per 15+ years ain't an issue. Big whoop. I shot that negative out of my mind a year ago.

But really. there aren't a lot of Cozys with 540's in them. The 360 is a very good powerplant.[stifle yourself Chrissi ]

[Neverquit]

Going for initial powerplant purchase cost they're really close in price and availability. I haven't looked too much in prop applications. I'm assuming they're the same? Is there a possible problem in over-spinning on the 540?

[Edge 513]

Ask Chris about the nuances.

Tidbit; I have a friend who owns an older Mooney, who says that the P-factor will be immense with a 540, since whatever his friend flys has one and was alarmed by it. I don't understand that. But anyways, Canards aren't as affected by Pfactor...only a peefactor factors in with being able to fly for 5 hours. My friends Mooney suck gas, is slowwww, and is good for only a few hours duration...so he is in denial about Cozy's, even ones that have 360's in them like his utilizes. Of course he has a cute Lacoste style shirt with a Mooney logo on it...so he is happy. [Wheres the applause emoticon]

[Marc Zeitlin]

... I haven't looked too much in prop applications. I'm assuming they're the same? Is there a possible problem in over-spinning on the 540?

Prop selection is dependent upon the power availability and speed expectations. Since power absorption drives blade area and prop diameter is limited either more blades or more chord is necessary for the 260 HP from an O-540 than is required for a 180 HP O-360. Since the aircraft is expected to fly faster, more pitch will be required on each blade. Assuming that the correct expectations for power and speed are given to the prop manufacturer (and these expectations are based on airframe performance, meaning the drag curves), the prop manufacturer will give you a propeller that's tuned for your application.

 

In either case, if you ask for a climb prop, or if the inputs are incorrect, you'll be able to spin faster than redline, either at off-design point operating points or anytime.

 

It's certainly not dependent upon what engine you have - the prop design process is the same either way, and you do NOT use the same propeller.

[Waiter]

"P" factor isn't a factor on a EZ.

 

P factor (on a convential airplane) is caused when propellor airflow is kind of corkscrewing as it passes over the fuselage and hits the rudder at a slight angle.

 

Most aircraft manufactures correct for this by mounting the rudder with a slight angle.

 

Torque is a minor factor, next time you pass by a bunch of EZ's parked on the ramp, take a look at the position of their ailerons.

 

Waiter

[Drew Swenson]

Pfactor caused during rotation on takeoff when the blade sees a different aoa between the ascending and descending blade. I have always wondered why we do not feel it in EZs. Is it because the engine is backwards and the precession effect during rotation is countering the p-factor?

 

What Waiter points out is the slipstream effect caused during full power at no or slow speeds----and has no effect since no corkscrew effect over the rudders. He knew that though---his feet just automatically compensate no matter what plane he is in.

[Arbiter]

Going for initial powerplant purchase cost they're really close in price and availability. I haven't looked too much in prop applications. I'm assuming they're the same? Is there a possible problem in over-spinning on the 540?

Forgive the Noob here, but when I looked at a 360 Vs. 540 at the sites I was at (Lycoming, and others) there was a HUGE difference in price. The 360's I saw were about $23-25K NEW and the 540's were $65K+ NEW. Am I gravely mistaken that this is the true price difference?

 

I was planning to use the 360 but if the 540 reall isn't that much different (For me that's like $27-35K instead of $65K) than the 360 then I would tend to go with more power and retracts to get the added speed advantage and the performance benefits. I saw info on Chris' aircraft and I thought I saw cruise data saying the fuel burn was comparable to a 360 in his cruise configuration with a constant speed prop...

[Edge 513]

Chris does not have a CSProp. Rebuilt 0540's are in the 32k range. Add for EI and FI and etc. Also rebuilt to 'as new' is the way to go. These engines are in high demand by the RV guys so they are somewhat hard to come up with. If you go to Barrett or Precision you WILL pay 46+k for your engine.

[Neverquit]

I'm getting 25K rebuilt for a 360, 35K for a 540 rebuilt. But these can vary from place to place. I found them as low a 10K for a 360. I won't buy a new one.

 

These engines are in high demand by the RV guys so they are somewhat hard to come up with.

You're speaking of the 360's correct? They're also very popular in Pitts, Eagles, and so on.

[Edge 513]

No, the 540's I have been told are rabidly wanted. Frothing at the mouth, many are, for go fast RV's. Most probably know this but a CSProp will get you great take off performance, but not be near as fast as a cruise or speed prop when they are feathered for cruise. The CSProp is not the answer to both needs, that is why I opted for540 power. As Marc said to me a year ago, "with that 540 you wont have to worry about density altitude takeoffs at gross, and you will have ALL the speed you want". Then there came the wing changes.

[Edge 513]

Boy that 3rd sentence finished out wrong. You guys know what I mean. Fixed props for cruise or speed or climb. Feathered CSProps.

[Big Steve]

I have a 0360 and I did not pay big bucks for it. You just have to look around be patient and be willing to do your own work on it. Build on STeve

[longez360]

I have an O-360 on my Long EZ and I'm happy with it. I had it built by Aero Sport Power in Kamloops, BC Canada. It would be worth pricing the 360 and 540 with them. I have never had better customer service than from ASP. Bought my engine in 1999, had it delivered to Melbourne Australia. In 2002 I went to Seattle for 3.5 years and took my 60% complete LEZ. I bought 9.2:1 pistons for it. They put the new pistons in, repainted the engine, gave it a once over and delivered it back to me in Seattle for no charge. When I built up my new downdraft cooling system they sent me an old 360 pot to Australia to use as a mold. No charge. I've gotten various bits and peices as I changed my Long EZ systems, nil charge... Never ends. My buddy Rob is building an RV-8 and just bought an O-375 from them... Yes, an O-375.

 

If building a CozyIV I would install a 540, providing I had the extra time to make the changes. Being out of the air is NO fun. There is one thing for certain, I would contact Bart and Sue at ASP for the engine, without hesitation.

[Arbiter]

Wow,

It's great to hear such good responses about this! I was definitely under the wrong impression about the prices of the engines, which I am happy to hear! I'll have to consider the 540 now in my plans, still not sure if I'll go that route though. It sounds like the benefits are improved top end performance, improved rate of climb and TKO distance without the worry of density altitude effects. The price you typically pay would be about $10K more, and requires modification of the turtledeck. You also pay with greater fuel burn, but can get similar burn @ cruise. I would imagine the oil cooling system needs to get larger presumably with a larger heat load. From a front seat weight perspective, does it help much to have the larger engine in the back to balance out the CG? I'll do some more digging into that in the next couple days! Thanks again!

 

-Chris

[NeilK]

I'll throw my hat in the AeroSport Power admiration ring as well. I bought an O-360 from Bart for my RV7 and it ran perfectly from first start. I know at least 5 others that purchased O-320 through IO-540s from Bart and all are extrememly pleased. Their customer service is the best, not only in the aircraft engine community but as a bussiness in general. I can not think of any bussiness I've dealt with in the past 30 years that treats it's customers with such respect.

 

http://www.aerosportpower.com/

[brendanw]

Here's a good on ... does anyone happen to have a relatively accurate 3D CAD model of an O-360? I'm going through the motions to create one at the moment, but I would rather not reinvent the wheel.

 

Also, we picked up our O-360-A1A from Aero Sport as well. We've only got a couple of ground run hours on it thus far, but it runs like a champ!

[Arbiter]

Here's a good on ... does anyone happen to have a relatively accurate 3D CAD model of an O-360? I'm going through the motions to create one at the moment, but I would rather not reinvent the wheel.

 

Also, we picked up our O-360-A1A from Aero Sport as well. We've only got a couple of ground run hours on it thus far, but it runs like a champ!

 

I would imagine the important parts of the CAD model would be the main dimensions and the precise locations of all the attach points. I would be interested in one too if anyone has it, I was going to model this at a later date but will welcome anyone who has a model they are willing to share! Thanks for bringing this up!

 

-Chris