szutowiczrv10

szutowiczrv10

Member
I recently heard about this engine and wondered if this would be a good match for the RV-10 from Vans. It is lighter has the same Horse Power as the IO 540. I have also heard that the IO 540 actually is slightly heavier changing the CG. I read that in some thread. It seems this engine would be a good match for the RV-10. Any thoughts on this? Price seems very nice for a completely new engine and a three year warranty to boot.

Here is the Website. http://www.xp-360.com/index.asp?content=15
 
It's a RACING engine!

You know, Superior's marketing on this engine troubles me. SRE is supposedly Superior's racing arm, and this engine was raced in Scotty Germain's Lancair to prove its mettle.

Yet the web site makes it sound like it's a perfectly reasonable engine for your RV-10--and I don't think it's anywhere close to appropriate.

A few things not said on the site: How fast is it turning to get 250 hp? What's the real TBO at 250 hp (not some imaginary number derived from statistical analysis by a chimp)? I'm pretty sure you'd need to rev that engine to 2800-2900-mabye 2950 to get that power. Fine, but what does that leave you with at an engine speed you'd use every day?

Let's say the engine makes 250 hp at 2900 rpm. That takes 453 pound-feet of torque to pencil out properly. Now, let's give the XP-400 the benefit of the doubt and say it makes the same torque at 2500, why that's all of 215 hp. I doubt it does make the same torque at 2500 as it does at 2900, and absent a dyno chart it's hard to know exactly, but a WAG has it around 410 pound-feet, which leaves you with 195 hp.

Now look at the IO-540. To make 260 hp at 2700 rpm, we're looking at 505 pound-feet of torque. Assuming the torque curve is relatively flat to 2500, you're looking at 240 hp at that speed.

Don't get me wrong, I think the XP-400 looks like a good engine. And, as I have a sorta distant cousin of it in my IO-390, then I'd better be on board. <grin>

But as a replacement for an understressed six-cylinder in a "family style" airplane? Nope.

--Marc
 
Compression ratio

The Superior site doesn't really give information on what rpm they turn to get the power specs. But, it you look at the XP-400 at 220 hp, it has a 8.5:1 compression ratio. The XP-400SRE has a compression ratio of 10:1. I'm not sure if the extra 30 HP can be accounted solely on the compression ratio, but my guess is that the SRE also has better porting and valve size and geometry. I'm guessing here but I think that they got the HP values of both engines at the same RPM.
That said, I'd love to put a turbo normalized XP-400SRE on -10.
 
I would not be tempted to put a highly tuned engine in an RV-10, just because I'd prefer the presumed reliability advantages of an engine in "normal" tune.

That said, I'm surprised that the market isn't pushing Van's to create the firewall forward components that would be necessary to install an 0-390 or 0-400. The O-540's are expensive and thirsty, and I would think that many people would be very happy with a 220 hp (+/-) four cylinder RV-10. Losing 10 knots in cruise isn't a big deal, and the reduced climb performance wouldn't have a big impact on most of us who are flatlanders.

Of course, I'm a guy who's very happy flying a 160 HP, fixed pitch, VFR RV-6....
 
I am looking to soon take the plunge and start an RV10, and this is exactly what I would like to find, a good ~220hp engine option. Something that would give slightly reduced performance and hopefully significantly reduced fuel burn. What happened to the 210hp RV10 that Vans tested?
Bill
 
You should call (or write) Van's and tell them you are interested in that option. When I've spoken to them at various airshows, their response has been:


"If enough people called wanting to use a smaller engine, we'd provide the components, but nobody wants to install anything smaller than the 250 or 260 hp 6 cylinder engines".
 
i am building a rv-8 and i am thinking of the io-400 probly the 220 horse but i would like to know the tbo on the 250 horse. 30 extra horse with no weight gain that would be nice power to have in reserve :) .
 
From superior: 250hp @ 3000 rpm with high comp pistons. Personally I am not worried about the engine at 3000rpm, its the prop that concerns me. If it threw a blade at that rpm the whole airplane would literally self-destruct.

Then it would be deady gone goodbye. The 220hp version is at 2700rpm and sounds better as a everyday use engine. But then again thats only my opinion.
EJ.
 
fmarino1976 said:
The Superior site doesn't really give information on what rpm they turn to get the power specs. But, it you look at the XP-400 at 220 hp, it has a 8.5:1 compression ratio. The XP-400SRE has a compression ratio of 10:1. I'm not sure if the extra 30 HP can be accounted solely on the compression ratio, but my guess is that the SRE also has better porting and valve size and geometry. I'm guessing here but I think that they got the HP values of both engines at the same RPM.
That said, I'd love to put a turbo normalized XP-400SRE on -10.
Click to expand...
Another consideration concerning compression ratios. Higher compression ratios don't tend to run as smoothly. I changed the CR on my O-320 from 7:1 to 9.5:1 and would not do it again. In a "family" type cruiser like the -10 you really want a smooth engine.
 
CG

This engine should weigh a lot less than a 540, which should help with the CG forward issues that the -10 has when flown solo, or only front seats.

Trouble is, what will it also do to the aft CG when loaded with 4 passengers + baggage??

As I see it the engine will be about 5 or 6 inches shorter----to use the same cowl, it will require either a longer motor mount, or a prop spacer-----or a combination of the two-----to adjust where the CG of the engine is in relation to the airframe. Perhaps an entire firewall forward package even.

While it is nice to daydream about a different powerplant, there are a few engineering details to be worked out first.

Mike
 
I have asked for conderation of other 210-220 hp engine options and will post any response. It would help if others would also write and ask.
 
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