Superior Engine news-XP-400

[Captain_John]

To me, it is flutter that is the critical issue.

Caveat... I aren't a en-gah-near, but from what I gather this is where the airframe meets it's design limitations.

My real reason for wanting the hosses is for climb and short field performance. I just LOVE the rush of acceleration!

The way I see it, if I don't tempt fate and play in the twilight of flutter scenarios, I should be around to tell you how it all works for a long time!

How far off am I? I don't think too far off...

CJ

[n615ks]

Any pictures, notes and (in the near future) performance would be greatly appreciated. The 390 just seems like a perfect alternative to the high comp IO-360, without the negs!
I've got a good ways to go yet, but getting close enough to nail this thing down

[BruceMe]

Originally Posted by AX-O

Wonder what the fuel burn rates will be.

Trivial to calculate, as engines are engine are engines...

They claim 210hp max, .45 BSFC. That translates to 11.8 gal/hr @75% and 9.5 gal/hr @ 60%. But the 60% rate will still have all the power of an O-360 (180hp) @ 80% power.

Because they are going low compression, these numbers may be a little worse. like 12.5 and 10.5... But they are definatley within a gph.

So you do have the option of using lower power settings to cruise like an O-360 at the higher power settings, but who will do that?

-Bruce

[Mel]

I know that everybody is going to disagree with me on this, but, Van designed these airplanes to be light weight fun airplanes. Mine -6 weighs 1009 lbs. with a 3-blade Catto prop. Most airplanes that I now inspect with the constant speed props, autopilots and full instrument panels weigh over 1100 lbs. If you guys will seek out and fly an RV that weighs around 1000 lbs. you will be shocked at how much better they fly.
Mel...DAR

[f1rocket]

Originally Posted by BruceMe

So you do have the option of using lower power settings to cruise like an O-360 at the higher power settings, but who will do that?

-Bruce

We do that routinely using the IO-540's otherwise the fuel burn will put you in the poor house. It's nice to have the acceleration and power at takeoff but I quickly throttle back to around 22 square to keep the fuel burn around 10 to 12 GPH. I would think that the extra horsepower would allow you to fly faster and more economically at higher altitudes.

[praterdj]

My biggest concern is weight. I am building an 8 and I?m a healthy boy?6?-5? at 250 pounds. I?ve already made the decision to put the battery in the back and anything else I can safely relocate. I don?t want to have to carry a lot of ballast to allow the nose to be held up on solo final.

In discussions with others they suggest (I know everyone has an opinion and are usually quick to share them but I see the logic in this) the IO-360 that is 30-35? pounds lighter than the angle valve, 200-HP model with some enhancements. They have said that top end speed is about the same. I?m not sure about climb out performance.

I am still gathering information to allow a more detail oriented decision but I think this is the way I?m going. I can?t afford additional 30 or more pounds on the front end.

I also totally agree with Mel?s statement. In any type of performance machine weight is critical. At some point removing small amounts of weight will do more for performance than adding a couple of horsepower.

I know I?ll get slammed by those with endless budgets that thing money doesn?t factor into the decision but I also must consider the impact that it may have on both initial purchase price and INSURANCE. The way insurance is skyrocketing (one of the few things that can out climb and RV ) I don?t think I want to give them any reasons to jack up the price.

Donald
8 ? Empennage underway
N-284DP (Reserved)

[BruceMe]

Originally Posted by Mel

I know that everybody is going to disagree with me on this, but, Van designed these airplanes to be light weight fun airplanes. Mine -6 weighs 1009 lbs. with a 3-blade Catto prop. Most airplanes that I now inspect with the constant speed props, autopilots and full instrument panels weigh over 1100 lbs. If you guys will seek out and fly an RV that weighs around 1000 lbs. you will be shocked at how much better they fly.
Mel...DAR

For the record... My -4 is Day/Night VFR, 320 powered, no vacuum, nice light wood prop... I haven't weighed it yet, but I'm shooting for mid 900's unpainted. Just the way Van wanted it

-Bruce

[MCA]

Well, it looks like there is some interest in a -390 web site. I'll probably get something up in the next few months.. for now I want to get the plane flying.

And... I promise to show data only from my build experieince. I don't want to get in the middle of weight, horsepower, fuel burn, etc. discussions!

Marc

[osxuser]

Originally Posted by Mel

I know that everybody is going to disagree with me on this, but, Van designed these airplanes to be light weight fun airplanes. Mine -6 weighs 1009 lbs. with a 3-blade Catto prop. Most airplanes that I now inspect with the constant speed props, autopilots and full instrument panels weigh over 1100 lbs. If you guys will seek out and fly an RV that weighs around 1000 lbs. you will be shocked at how much better they fly.
Mel...DAR

I agree that it would be a lot more of a FUN airplane, however, I'm building the RV to be a traveling machine, therefore 180/CS is a minimum for me, as well as full IFR capiblity. = at least 100LB heaver than ideal.

[sprucemoose]

Originally Posted by osxuser

however, I'm building the RV to be a traveling machine

Hmm. Just curious why you're not considering a 9 instead of a 7? The 9 seems more like a traveling machine.