210 HP with IO390. Vote

[Tommy]

Based on everything that I know about the 390, I would probably not flinch about making the switch.
Especially considering I have 50 gal. tanks. The additional fuel required would never be missed. At least by me anyway.

[Gary]

Well, lots of posts in here are anticipating that it will weight more. I have no problem with the weight myself (I weight 160 lbs), but others fly it that are more standard-US-male size. Put two of these guys up front and you could have a problem. I refuse to add dead weight just to work around this problem. If the engine weights the same, I'm fine. Just don't want to make it worse. In fact, that's why I still have a MT prop.

I don't think the loss of 5 kilos was a big deal compared to the benefit in CG. I formerly weighed as much as 244 lbs but am now down to 190 so I had little choice when flying with another heavy front pilot or passenger to add a couple of bags of lead shot to the baggage area. The 5 kg solution was much preferable.

[Antoine]

It seems this thread is coming alive again?

Here is where I left it with the Lycoming Echelon program manager:
He said he planned on putting the DA40 STC on his 2012 budget and wanted to hear more from us. We agreed he would monitor this thread, but as you can see, the interest is not overwhelming, so I don't know what he decided to do.
I can ask if you are interested.

This project is to some extent in competition with the supercharger STC by Forced Aeromotive - and this one is definitely moving towards an STC.

The IO-390 is slightly heavier ( a few pounds) than our IO360. It is as heavy as the 200 HP IO-360's, hence the possible confusion.
The engine is unfortunately not exactly the same size. IIRC it is shorter and wider.
The cost is not going to be small, even at TBO: new engine + STC, new cowling (I suppose), new powerflow manifold (?)

The IO/390 is also not compatible with MOGAS due to its higher compression. That is not a problem today because the DA40 is not certified for MOGAS, but it is just a limitation to be kept in mind... for the day AVGAS goes away...

In terms of benefits, the IO/390 will provide a significant increase in climb rate and a nominal increase in top speed. I would expect it to be slightly more fuel efficient than our IO/360 thanks to the higher compression and should be neutral in maintenance costs.

I think the supercharger is a better alternative in terms of performance benefits while not as good on fuel efficiency, especially down low and somehat more costly to maintain. It is also a potentially dangerous solution because it depends solely upon pilot action to keep MP below damaging values.
I only expect the supercharged DA40 to shine above FL100 or so, but then it should be a really nice 150-160 knot cruiser with moderate fuel burn and plenty of climb rate for getting on top or punching through an icing encounter (inadvertent of course ).

In a nutshell, I believe the only way this IO-390 project can be made to fly is if a combination of Lycoming and Diamond decided to pursue the STC.
Diamond should take the opportunity to optimize engine cooling and plug a few ugly drag holes at this occasion and maybe we get our DA40-V1 someday... Hello Diamond?

[cbrinton]

Any idea what the likely increase in MTOW would be? I assume that would only come if Diamond got together with Lycoming on this.

[Joey]

If the landing gear for the austro version of the DA-40 can be "bolted on" you would have an 80 kg or 176 lb increase. That would work for me.

[Antoine]

Imagine this combination:
IO-390 + new engine mount
> increased climb rate, moves CG forward. Also increases top speed by 5 knots for... bragging rights...

New cowling/plenum with optimized cooling
>less drag, more climb, more economy and speed (another 5 knots, but these cost no extra fuel)

New landing gear similar to 40NG but streamlined, well faired-in and 2 in more prop clearance >Increased MTOW by 175 lbs, no more corked NLG, less drag, more climb more economy and speed (maybe 2-3 knots at no extra fuel cost). Useful load 1000 lbs!

TKS de-ice with (small) fluid tank behind passenger seats (under luggage compartment).
>3-5 knots less speed due to TKS install, useful load down to 940 lbs or so.

Large (80 in) 2-blade composite prop with TKS slinger ring
> more economy and speed vs MT 3-blade (5 knots at no extra fuel cost).
Check the US site of MT-prop for comparisons between large diameter 2-blade and smaller 3-blade props with 180-200 HP engines.

Result:

Useful load with full fuel and TKS: 940-300 = 640 lbs ))

Out-climb the XLS at same load or match it at new MTOW (guessing here!)

Inadvertent icing protection

Cruise 8-10 knots faster than XLS on same fuel burn. That's around 150 KTAS under 10 GPH or 140 KTAS at 7 GPH

Max cruise 13-15 knots faster than XLS

What can the budget be?
Engine + mount + cowling + powerflow mod
Landing gear
TKS
Prop

[Lance Murray]

I have flown with an IO390 on a Glasair Sportsman 2+2. Glasair may be able to enlighten us on the real-world benefits of the 390 vs the 360 as they regularly do both installs on their aircraft. One interesting thing that I found is that the 390 is ready to be fitted with a turbo.

http://www.glasairaviation.com/sportsmanspecs.html

I am guessing that the true benefit of the 390 is shorter takeoff, increased climb at heavier weights, and slightly better performance at higher altitudes. Increased cruise speed will be at the expense of increased fuel burn. Pull it back if you don't want the burn.

All of that being said there is a saying from my old motocross racing days:

"there is no replacement for displacement"

If it is time for an overhaul and Lycoming will give me a good core price or I can get a good price on the re-sale market then I am in.

[Antoine]

enlighten us on the real-world benefits of the 390 vs the 360 as they regularly do both installs on their aircraft.

http://www.glasairaviation.com/sportsmanspecs.html

I am guessing that the true benefit of the 390 is shorter takeoff, increased climb at heavier weights, and slightly better performance at higher altitudes. Increased cruise speed will be at the expense of increased fuel burn. Pull it back if you don't want the burn.

Hi Lance, thanks for your input and the link. According to the Glasair web site they see a much bigger increase in cruise and top speed between the 1180 and 210 HP version- almost 10%. That's amost double what the rule of thumb says... I don't understand... But even 5% would be 7-8 knots, so I guess I was being overly conservative...

PS: I'm here this week-end for our Skype call!

[Tommy]

...
"there is no replacement for displacement"

If it is time for an overhaul and Lycoming will give me a good core price or I can get a good price on the re-sale market then I am in.

Correction; "there ain't no replacement for displacement" No truer words have ever been spoken.
The 390 is the perfect upgrade for this airplane. A little bit more of everything would make this plane the cats meow.
I am not really that concerned about getting a good core price or outright resale for that matter. Given the world economy as it exist now and for the foreseeable future, people are going to hang on to there airplanes for a long time. Replacement for existing 360s will keep the demand up for a long time. The IO-360 has a nice niche in that it has a proven rock solid record and it's not a fuel hog. Bang for the buck cannot be beat.
The only thing that I see that might have to be modified or replaced would be the engine mounting bracket to accommodate the shorter dimension of the engine. Probably total replacement of the frame. Nothing insurmountable that's for sure.
With the additional weight, I would probably have a perfectly balanced airplane. I don't even care if I have to go experimental. This is probably my last airplane. I really don't give a damn about resale. The 390 will probably be my next major upgrade.
Does anybody have any idea what G 1000 changes would have to occur. On the surface it would appear very little, but, then again we are talking about airplanes.

[Antoine]

I don't even care if I have to go experimental.

Is this an option at all? I'd love to know how it can work.

This is probably my last airplane.

lol . 'm glad you put "probably" in there!