2 stroke direct injection engines conversions or ready available ones for aircraft?

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erkki67

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Hi there

I’ve been flying for years with different Rotax 2 stroke engines quiet happy.

Today I would to continue with a 2 stoke engine, but would need a bit more fuel efficient set up and around 100hp (80 -120hp).

id like to see on my propshaft 1650 to 2300 rpm.

my favorite engine would be a Rotax 850 e-TEC, but those are only built for non flying applications and have no hard points for a PSRU.

Does there exist any similar 2 stroke engine configurations, with direct injection and hard points for a PSRU?

rgds Erkki
 

pictsidhe

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Hi there

I’ve been flying for years with different Rotax 2 stroke engines quiet happy.

Today I would to continue with a 2 stoke engine, but would need a bit more fuel efficient set up and around 100hp (80 -120hp).

id like to see on my propshaft 1650 to 2300 rpm.

my favorite engine would be a Rotax 850 e-TEC, but those are only built for non flying applications and have no hard points for a PSRU.

Does there exist any similar 2 stroke engine configurations, with direct injection and hard points for a PSRU?

rgds Erkki
A custom set of crankcases would open up a lot of options. Rotax has been making it hard to adapt engines for liability reasons.
 

erkki67

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Now, out there in the wild aren’t only Rotax, what other kind of similar bangers are out there where a PSRU could be installed?
 

Armilite

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Hi there

I’ve been flying for years with different Rotax 2 stroke engines quiet happy.

Today I would to continue with a 2 stoke engine, but would need a bit more fuel efficient set up and around 100hp (80 -120hp).

id like to see on my propshaft 1650 to 2300 rpm.

my favorite engine would be a Rotax 850 e-TEC, but those are only built for non flying applications and have no hard points for a PSRU.

Does there exist any similar 2 stroke engine configurations, with direct injection and hard points for a PSRU?

rgds Erkki
===========================================================================

As far as I know, Nobody has converted an eTec yet for Plane use! They all have to be derated to Max 6500rpms to live longer, preferably lower.
At 6500rpms it takes on Average 7cc to make 1hp. So your:

80hp x 7cc = 560cc
90hp x 7cc = 630cc
100hp x 7cc = 700cc
110hp x 7cc = 770cc
120hp x 7cc = 840cc

Unless you use a Turbo! To make Good HP you need to make your Engine efficient. That means using the Max CR for the Octane Fuel your using. Like for 91 Octane 11.5cr is what I would use. Using the right Size Carb for the Max Rpms your using based on your Engine Bore & Stroke and CFM made, and using a Good Wide Band Tuned Pipe. All Rotax UL Water Cooled Engines use 11.5cr. They use 36mm Bing 54 Carbs. Example: A Rotax 582UL is 580cc, use's 36mm Bing 54's and use's 11.5cr, so Why isn't it making 80+hp? It doesn't use a Tuned Pipe, it use's a Muffler. At 93% efficient it makes 124cfm. So what CFM does (2) 36mm Bings provide? 86.2cfm x 2 = 172.4cfm. On 2 Strokes the Port is only open say half the Time so it Gulps Air, so a Bigger carb may Help a little on the Top End.

Rotax 582UL with an R&D Tuned Pipe. Dynoed [email protected] 580cc/7cc = 82.9hp. The Peak Flow/HP Calc says at 93% effiecent at 6500rpms = 83hp!
http://www.rotaxservices.com/dyno.html#3

#1 You do have the Option to hang one upside down on some Aircraft and use a Belt Drive.

#2 You have the Option to make a New Billet CNC eTec Case with the Rotax Provision 8 Gear Drive Data. Probably around $3000 if you can't do it yourself.

#3 You do have the Option to use a Skidoo/Rotax 670 or it's 720-748 Big Bores that has the Provision 8 Gear Drive Data and just make an eTec Head for it. But Etec Technolgy is more for Emissions, not for making HP. If you used the Full Synthetic Oils and EFI you would get the same results! They use very Large Throtle Bodies on the eTec's, if I remember right 54mm. The Biggest Carbs used on a 670 were 44mm. The Standard 670 used 11.5cr and was rated [email protected], and the 670HO used 12.5cr and better Ported Cylinders and was about 20hp more. A one off eTec head would probably cost around $1500.

#4 Your 1650 to 2300rpm. For anything over 65hp you want to use the C or E Gear Drives. The C gear box is available in ratio's 2.62:1, 3:1, 3.47:1, 4:1.

1650 x 2.62 = 4323rpms
1650 x 3.0 = 4950rpms
1650 x 3.47 = 5725.5rpms
1650 x 4.0 = 6600rpms

2300 x 2.62 = 6026rpms
2300 x 3.0 = 6900rpms
2300 x 3.47 = 7981rpms
2300 x 4.0 = 9200rpms

A Skidoo/Rotax 670 with R&D's 618UL Tuned Pipe! The 670 is the 617/618UL Big Brother, so you could turn it 6750rpms for 100hp.
http://www.rotaxservices.com/dyno.html#89

Skidoo did make a Triple in 1993 with a Provision 8 Case, I think it was called a 748. I think it was (72mm x 61mm) 745.4cc. Use that Case to make a (82mm x 70mm) 1109cc using 670 Cylinders and Crank parts and you would have an awesome engine.

PSI makes some CNC Billet Engines up to 1800cc based off Polaris Engines.
 

Armilite

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Now, out there in the wild aren’t only Rotax, what other kind of similar bangers are out there where a PSRU could be installed?
In the 80hp to 120hp Off the Shelf, Rotax, Hirth, Simonini, Jabaru, Mkz.
 

erkki67

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Armilite, Hirth, does not have the best reputation over here regarding after sales service.

Rotax, have the 2 stroke engines but no PSRU made form them.

Simonini, indeed is an interessting contender, and I read that they are developing an injection system for their Victor.

Jabara (Jabiru) if it’s the first one never heard about it, and for the second one I didn’t knew thei where building 2 strokes as well.

Mkz who’s that, and where are they from?

Rgds Erkki
 

Armilite

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Armilite, Hirth, does not have the best reputation over here regarding after sales service.

Rotax, have the 2 stroke engines but no PSRU made form them.

Simonini, indeed is an interessting contender, and I read that they are developing an injection system for their Victor.

Jabara (Jabiru) if it’s the first one never heard about it, and for the second one I didn’t knew thei where building 2 strokes as well.

Mkz who’s that, and where are they from?

Rgds Erkki
=======================================================

Yep, that's why Hirths are not seen much here in the USA. Only One Service Center in the whole USA, Simonini also. Jabiru Engines are used on Airplanes and are 4 Stroke only, but not used much here in the USA. Compact Radial Engines make the MKZ line of Engines out of Canada, and only sell direct that I know of. Their Direct website seems to be down at the moment. All CNC machined.
https://fiate.net/en/h-default.html

Rotax still makes the B Gear Drive, C Gear Drive, and E Gear Drive. Lot's of Good Used ones around also.

E Gear box
https://www.cps-parts.com/catalog/rtxpages/2strokeegearbox.php

B Gear Box
https://www.cps-parts.com/catalog/rtxpages/2strokebgearbox.php

There are some Adapter Plates to use other Brand Name Gear Drives out there for a Rotax also. There is also some belt Drives.

Jabiru
https://jabiru.net.au/engines/

Some Engine Prices
http://www.titanaircraft.com/engines.php

https://lockwood.aero/rotax-engines.html

Yes, I like the Simonini's also, especially the Victor 1 Super Single at [email protected]! But just too darn Expensive. Most Part 103 Ultralights only need 25-35hp and the Rotax 277UL can make that if built right. Small Kitplanes only need 35-55hp and a Rotax 377/447 can make that. The 503UL can make 50-70hp and covers the middle range of Kitplanes, and the 582UL(65-80hp) and Rotax Rick 670(92-105hp) cover the Bigger Kitplanes.

PS If you look on Simonini's Itlay website, Rotax Drives are way cheaper.
 
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erkki67

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

I had an interesting emailexchange with Paolo Simonini.

It seams that they are working on a indirect EFI into the intake.

It’s an interesting concept that needs to be listen at, but he couldn’t give me a release date nor pricing.

The bar is set by Rotax and their direct injection, both for environmental reasons as for consumption figures.

Their injection system allows to inject the fuel as soon as the exhaust ports are closed, so no fuel mixtures is being sucked out by the outstreaming gases.

I would like to know, by how much the indirect injection can limit the spilling of the fuel/air mixture?

For what I’ve in mind, the Victor 2 is the engine to go.

Indeed, the pricing could be a bit more two stroke like, but hey, mr Simonini has to pay other bills too from what he is selling.
 

Armilite

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

I had an interesting emailexchange with Paolo Simonini.

It seams that they are working on a indirect EFI into the intake.

It’s an interesting concept that needs to be listen at, but he couldn’t give me a release date nor pricing.

The bar is set by Rotax and their direct injection, both for environmental reasons as for consumption figures.

Their injection system allows to inject the fuel as soon as the exhaust ports are closed, so no fuel mixtures is being sucked out by the outstreaming gases.

I would like to know, by how much the indirect injection can limit the spilling of the fuel/air mixture?

For what I’ve in mind, the Victor 2 is the engine to go.

Indeed, the pricing could be a bit more two stroke like, but hey, mr Simonini has to pay other bills too from what he is selling.
=========================================================

While eTec Sounds & Looks Nice, on a Boat, on a Sled, it's not been tried and Perfected for Airplane Continious use for hours. Since the Case doesn't have Provision 8 Data for attaching a Rotax Gear Drive, your only Option is to use a Belt Drive and Hang it upside down, which it hasn't been used in that way on anything.

In the Sled World those Sealed Bearings they use for the Crank have Failed, usually around the 4000 mile range! 4000/40mph if Avg trail Speed = 100hrs!

I have seen where some College kids added Direct Injection to a Single Cylinder Bike and Sled Head, and a older Twin Cylinder Sled Engine.

IF, your using just a Muffler your loosing a 20-40% of Fuel right out the Exhaust. IF, you use a Tuned Pipe your not loosing as much account that's what a Tuned Pipe does is Force the Fuel Charge back into the Engine and makes it more efficent, means more HP! Don't need the extra HP, turn it lower rpms which means a better GPH. Example: Stock 277UL made Max [email protected] With R&D's Tuned Pipe it made [email protected] It probably made [email protected] Less Rpm and better GPH.

Like I said, use the Full Synthetic Oils at 100:1 and your Emmissions will Improve. Use a Good Tuned Pipe and your Engine will be more efficent making you more HP! Adding EFI will also Help your GPH!

Ecotrons sells EFI kits.

Off the Hirth Facebook Group: "Just a little inspirational flight from yesterday. For those of you in the process of installing, repairing, overhauling, or otherwise working on your Hirth engines. This is my 3202 in action. Still going strong after 380 hours in 3.5 years.

I asked what Type of Oil was he using.

Blue Max exclusively the entire lifetime of the engine. I used it religiously at exactly 100:1, but in the last 100 hours or so I have been fudging a teeny bit extra each time so probably 97:1 or so. I always add a teaspoon extra or so."
 

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Aviator168

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

@Armilite. Do you have a link to the site of those pictures you attached?
 

Armilite

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

@Armilite. Do you have a link to the site of those pictures you attached?
No, I don't. I found the photo's probably 2 years ago. Some different Colleges did those eTec projects, there was a third head, done on a newer 500/600 Engine but I couldn't find the photo. They made a New Billet Head.

Here is a Billet Head for an Etec Engine. That Insert could be added to any Head Shell.
http://www.bd-xtreme.com/index.php?id_product=311&controller=product

If you want eTec, the simplest solution is to just buy a good Used or New Crate motor. Hang it upside down and use a Belt Drive.

Etec gives you good Emissions but doesn't make you any more HP than Conventional Piston Port, Reed Port, Rotary Valve Engines.

I can tell you in Skidoo Sled use, they have had Crank Bearing problems around 4000-4500 miles. That would translate into 114-128hrs range if Average Trail Speed is 35mph. They use a Sealed Bearing with Isoflex Grease!

You would have Good Emissions if you just used the Full Synthetics like Hirth's Blue Max, Amsoil Saber, at 80, 90, 100:1.

You would have better GPH if you added EFI to any Older Rotax.

Depending on what HP/Engine/Weight you need, there is probably better Engine Choices.

But anything is possible if you have the TIME, the Skills, the $$$, to do all the R&D and Fabricating, and Testing.

Nobody, that I know of makes any Billet Case's for the eTec's either.

eTec's Computer has a Cripple/Limp mode built in, so you would want to use an Aftermarket Computer.
 

Armilite

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

ISOFLEX® LDS 18 SPECIAL A
Dynamically light, long-term lubricating grease
Service Temperature Range*, [°C] approx. - 50 to 120°C = -58°F to 248°F.


Clutches like Belt Drives can put a lot of Heat into the PTO Bearings. Over tightened Ultralight Belt Drives have melted PTO Crank Bearings that used Plastic Retainers. Always use Steel(#2) or Nylon(#1) Bearing Retainers. Nylon doesn't Rust or transmit Heat.

For an eTec Engine I would use the Hybrid Crank Bearings, Steel Races with Ceramic Balls with Nylon Retainers. Need less Oil/Grease, Run Cooler, last three times of a Conventional Bearing. But Cost a lot more.
 

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Battler Britton

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

here is a 2 stroke...3 cylinders, water cooled, turboed, intercooler, super charged...low pressure injection........................................drinking Jet-A1..!




8R6V7404.jpg

8R6V7407(1).jpg

Wam 100.jpg

WAM 100/120

100 or 120 hp @2750 rpm no PRSU

12 TO 16 Liter/Hour (Jet A-1)
 

choppergirl

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf



Can you inject Nitros Oxide / NOS into a two stroke aircraft engine without blowing it up? (the graphic above is a motorcycle engine)

I think it'd be pretty cool to have a red zone I can slide my throttle into past 100% marked "WAR EMERGENCY POWER"....
You know, when you need that temporary boost to get you out of a sticky situation, like over that tree line coming up cause you like to fly below 100 agl all the time.
I don't know who would want to do that, but I've heard some girls do...
 
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pictsidhe

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

How much cooling margin does your engine have?
If that's 'not enough', water injection would help. The Germans were big on methanol-water ADI war-emergency boosting.

Fine tuning one of these systems is going to be tricky. Get it wrong, your engine goes poof in 5 seconds instead of 60.
 

Armilite

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Re: 2 stroke direct injection engines conversions or ready available ones for aircraf



Can you inject Nitros Oxide / NOS into a two stroke aircraft engine without blowing it up? (the graphic above is a motorcycle engine)

I think it'd be pretty cool to have a red zone I can slide my throttle into past 100% marked "WAR EMERGENCY POWER"....
You know, when you need that temporary boost to get you out of a sticky situation, like over that tree line coming up cause you like to fly below 100 agl all the time.
I don't know who would want to do that, but I've heard some girls do...
==================================================================

NOS is for Drag Racing for a Short Burst 3-10 Seconds use, not for Continious use on any Engine!
 
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