Boost performance of Solo 2350 turbo (sustainer)

ucanem...@gmail.com

unread,

Mar 6, 2015, 2:14:12 AM3/6/15

to

Wondering if anyone has boosted the horsepower of a Solo 2350 turbo (or sustainer engine) to get better high and hot performance? If anyone has done this would like both positive and negative comments as to the work done, the results and what they did to boost engine performance.

Dan Marotta

unread,

Mar 6, 2015, 10:55:20 AM3/6/15

to

Just a word of caution...

When I was building my Harley, I asked the head porter for 10.5 or 11.5 to 1 compression and extremely high lift, long duration camshafts. He asked me if I planned to race the bike since, with each point increase in compression, I'd lose 10% or more in reliability. I opted for less performance and I'm glad I did. It's been over 100,000 miles since I built my engine.

Small aircraft engines produce a lot of power given their displacement and I've no doubt that increasing the power will reduce the longevity.

On 3/6/2015 12:14 AM, ucanem...@gmail.com wrote:

Wondering if anyone has boosted the horsepower of a Solo 2350 turbo (or sustainer engine) to get better high and hot performance?  If anyone has done this would like both positive and negative comments as to the work done, the results and what they did to boost engine performance.

--
Dan Marotta

Pierre Vav

unread,

Mar 6, 2015, 12:38:28 PM3/6/15

to

I was told that Ventus CT & Ventus CM engine were thery similar.
Ignition, carbs and exhausts differed.

Nice way to have fun and flames...

Charlie Papa

unread,

Mar 6, 2015, 6:30:52 PM3/6/15

to

On Friday, March 6, 2015 at 2:14:12 AM UTC-5, ucanem...@gmail.com wrote:
> Wondering if anyone has boosted the horsepower of a Solo 2350 turbo (or sustainer engine) to get better high and hot performance? If anyone has done this would like both positive and negative comments as to the work done, the results and what they did to boost engine performance.

Yes indeed, I have done it. It is not to INCREASE the horsepower so much as it is to RESTORE the horsepower that the 2350 was originally built to. It was de-tuned by tack welding a pair of constricting rings into the exhaust, and then reducing the jet size by one.

Mine is installed in a Discus 2cT, and as such, it is a sustainer. That means no throttle, no choke, no generator, - just the simplest get-you-home and lightest possible. If I understand correctly, the LBA required that it be able to sustain level flight, presumably in controlled airspace. With the full 28 HP it was built to, in level flight it would overspeed, which cuts off the ignition.

But using it in controlled space requires the use of headphones; a non-starter for me. I just stay out of controlled space. However, with the horsepower estored from the diminished 22 to 28, does it climb better. You better believe it.

The restrictor rings are tack welded in and very vulnerable to a Dremmel tool. Then you must remove the two jets, move the larger one in the rear (larger to overcome how much hotter it will run with already heated air from the front cylinder passing over it) and move it to the front, and then put the next larger size in the rear.

Don't mix up the covers for the pulse diaphragm that 'injects' the air/fuel; the front one should not have the hole that would make it vulnerable to the prop wash.

The result: MUCH improved climb, - perhaps 300 - 350/fpm vs. ~200. Hard to be exact as the vibration shakes the hell out of the varios.

And in ~1100 hours, there is less than 10 hours on the engine, because it is just a sustainer, and because I start it right off tow each day (because it's complicated and it starts faster if it has already run.

jfitch

unread,

Mar 6, 2015, 10:34:24 PM3/6/15

to

If you lose 10% reliability in a Harley, it's pretty much all gone, isn't it?

Sorry, don't know anything about the Solo engine.

John Galloway

unread,

Mar 7, 2015, 3:30:06 AM3/7/15

to

I have de-restricted a Discus BT and a Discus 2cT as described below. The

climb rate definitely improves but not as much as reported - from averaging

timed climbs and post flight analysis of flight recorder data I reckon you
get
about half a knot increase to average of 2.9 knots. Its still a worthwhile

improvement but you have to be aware the regulatory and possible
insurance considerations.

John Galloway

At 23:30 06 March 2015, Charlie Papa wrote:
>On Friday, March 6, 2015 at 2:14:12 AM UTC-5, ucanem...@gmail.com
wrote:
>> Wondering if anyone has boosted the horsepower of a Solo 2350 turbo
(or

>s=

>ustainer engine) to get better high and hot performance? If anyone has

>don=

>e this would like both positive and negative comments as to the work
done,

>=

>the results and what they did to boost engine performance.
>
>Yes indeed, I have done it. It is not to INCREASE the horsepower so much

>a=

>s it is to RESTORE the horsepower that the 2350 was originally built to.

>I=

>t was de-tuned by tack welding a pair of constricting rings into the

>exhaus=
>t, and then reducing the jet size by one. =20

>
>Mine is installed in a Discus 2cT, and as such, it is a sustainer. That

>me=

>ans no throttle, no choke, no generator, - just the simplest get-you-home

>a=

>nd lightest possible. If I understand correctly, the LBA required that
it

>=

>be able to sustain level flight, presumably in controlled airspace. With

>t=

>he full 28 HP it was built to, in level flight it would overspeed, which

>cu=
>ts off the ignition. =20

>
>But using it in controlled space requires the use of headphones; a

>non-star=

>ter for me. I just stay out of controlled space. However, with the

>horsep=

>ower estored from the diminished 22 to 28, does it climb better. You

>bette=

>r believe it.
>
>The restrictor rings are tack welded in and very vulnerable to a Dremmel

>to=

>ol. Then you must remove the two jets, move the larger one in the rear

>(lar=

>ger to overcome how much hotter it will run with already heated air from

>th=

>e front cylinder passing over it) and move it to the front, and then put

>th=
>e next larger size in the rear. =20

>
>Don't mix up the covers for the pulse diaphragm that 'injects' the

>air/fuel=

>; the front one should not have the hole that would make it vulnerable to

>t=

>he prop wash.
>
>The result: MUCH improved climb, - perhaps 300 - 350/fpm vs. ~200.
Hard

>to=
> be exact as the vibration shakes the hell out of the varios. =20

>
>And in ~1100 hours, there is less than 10 hours on the engine, because it

>i=

>s just a sustainer, and because I start it right off tow each day
(because

>=

Dan Marotta

unread,

Mar 7, 2015, 10:53:16 AM3/7/15

to

I guess you're right about that 10% reliability loss. I didn't consider that.

Great laugh - thanks!

Dan

--
Dan Marotta

ucanem...@gmail.com

unread,

Mar 7, 2015, 2:48:03 PM3/7/15

to

Any idea if the gliders by Alexander Schleicher Asw-28 E and Asg_29 E solo 2350 engines are also similarly restricted in power?

ueli....@gmail.com

unread,

Mar 10, 2015, 10:24:09 AM3/10/15

to

According to the manuals the ASG29E has 18kW@5400rpm. The unrestricted engine has 19.6kW@5500rpm.

danlj

unread,

Mar 14, 2015, 8:53:34 AM3/14/15

to

My experience, a few years ago is that phoning Solo got me the engine designer, with all the right answers instantly, no BS. t.e.l.e.p.h.o.n.e -- it's old technology. Involves something called "conversation."

miha.a...@gmail.com

unread,

Jan 4, 2019, 7:37:15 AM1/4/19

to

Hy,

Does anyone know where is this 'restrictor' located on a Scheleicher version?

Anyways i gues it is coverying a portion of exhaust valve?

Thanks for the answers in advance.

Regards