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

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#### Armilite

##### Well-Known Member
Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

25th of September we will got next order to install EFI on RMZ 500 engines. It will be first 500 engines with our EFI.
We planned to use one 46 or 49mm throttle bodies on them. If you think 46mm a bit small can install 49 mm or bigger.

We have an experience with reedported 550cc and got 64 hp from RMZ 550 engines at 6150 rpm using two 35mm throttle bodies.

RMZ engines - we use many parts of them like reed valves, air fans, carbs for our 294 and 350cc boxer EFI

This 350 cc engine use 38mm throttle body and produce 110 kg static trust with 1350mm propeller.

RMZ is not our mainstream. Just 1...2 per month. There are 10+ "car garage" level small shops which adopt this engines for aircraft use.
More peoples reworking RMZ ashobby.

We own 10+ CNC machines, electronic production Dpt, compositeparts production, test equipment... Can design and build anything.

38mm Carb = 96.0 [email protected] inch x2 = 192,ocfm - can you give me originsor math behind this formula?
5 inch ??? What is it - intake length or???
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CFM Measurements are taken on a flow bench at 5in. Water Test Pressure. The Carbs are Sized by their ID but very few Brands give each Carbs CFM Numbers, hence they just use 36mm, 38mm, 40mm, etc. Your Engines CFM needs is figured by your Engines Bore & Stroke and what your Max Rpm will be and it's Volumetric Efficiency which can vary greatly Brand to brand. If you have a Dyno Print of an Engine you can then compare. Like my Stock Skidoo 670(669cc)Dynoed [email protected], comes in at 94% efficent. So then you can just drop the rpm to 6500 and see it should make [email protected] if Tuned right. Every Tuned Pipe is different. A Standard 670 with an R&D Tuned Pipe made [email protected] and [email protected]
http://www.rotaxservices.com/dyno.html#89

For Airplanes use, Max 6500rpm. IF, you know an Engines [email protected] and most Companies Round-Up, so it's never the exact [email protected] Like a Rotax 277UL is listed [email protected], but when Dynoed by R&D actually made [email protected] If we use the Rotax 277UL Dyno Numbers, 268cc at [email protected] we come up with a Volumetric Efficiency of 67% using the Peak Flow HP Clac and making 38cfm. A 36mm Carb is rated 86.2cfm. If you allow for the Gulp effect of a 2 Stroke, 86.2cfm - 30% = 60.34cfm, some People use 86.2cfm - 50% = 43.1cfm. Now if your Turning your 277UL 6250rpms at 67% efficeint what their rated at, your Engine is now making 40cfm, if turning it 6500rpms now it's making 41cfm. The Stock 36mm Bing 54 should probably be ok. So the HP Restriction is probably in the Rotax UL Exhaust and Cylinder Porting. If you have access to a Dyno and most People don't, you can try different Size Carbs to see the effects. If you have the 46mm and the 49mm, you should Dyno both on the 500 and 550, then you will know.
https://www.mk5cortinaestate.co.uk/calculator3.php

For the 550F I would go with the 49mm, for the 500/503 the 46mm should work. Like I said, if you have it Carbed right and Exhaust right, your Power Band should be in a straight line 2000rpm to your Max Desired Rpm. It shouldn't drop off till past that Point usualy 150-250rpm. In your Dyno Software you should be able to break down the Data Info into says 50/100/250rpm incredments. Smaller the better.

So can you get a 250 Single Case drilled with Provison 8? If you can, I would like to Buy one to experiment with. PM me, I can send  by Paypal. I have a spare 277 (72mm) Cylinder & (66mm) Crank & Head, and I got a 550F (76mm) Cylinder and a 250 (61mm) Crank. (72mm x 66mm) 268.8cc or (76mm x 61m) 276.8cc combo's is possible.

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#### jbiplane

##### Well-Known Member
Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

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So can you get a 250 Single Case drilled with Provison 8?
Dont understand what this exactly means. I can do 3d scan of suitable case (old or broken is OK), than modify 3d model to simplify reducer connection.
250 cases on photo. They dont fit good to transfer ports of 550 cylinder. So may be better completelly mill case?

Please review case 250 photos, 250(500) and 550 cylinder.

#### Armilite

##### Well-Known Member
Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Dont understand what this exactly means. I can do 3d scan of suitable case (old or broken is OK), than modify 3d model to simplify reducer connection.
250 cases on photo. They dont fit good to transfer ports of 550 cylinder. So may be better completelly mill case?View attachment 74203View attachment 74204 View attachment 74205View attachment 74206View attachment 74207

Please review case 250 photos, 250(500) and 550 cylinder.
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Yes, that 250 Case. A 3D Model of the Case would be great, how much? I believe the bare case in the photo's is $80usd. The 500F/503F/503UL and 550F Case use a Head/Cylinder (4) Bolt Pattern based on a 100mm Bolt Circle with 8mm Studs. Not sure what the Old or New 250 uses. Most Older 60's to 2000's Skidoo/Rotax Singles 247, 277, 292, 299/300, 318/320, 335/340 Singles and the 503F and 550F all used the same (4) Bolt 100mm Pattern. The Skidoo/Rotax 377/380/377UL, 440F/447UL, 470(LC)/463UL, Twins all used a (4) Bolt Head/Cyinder Bolt Pattern based on a 94mm Bolt Circle. Since the 250F Single use's a 72mm Piston, I'm assuming it uses a 100mm Bolt Pattern. But I could be wrong, it might be 94mm! If 100mm I would think the 500F/503F/503UL Cylinder would just Slip-on. The Skidoo/Rotax 377/380/377UL/380HO, 440F/447UL all use the same Case & Crank. The 440F/447UL is a 67.5mm Big Bore of the 377/380 (62mm Bore). By my Calcualtions with the 94mm Bolt Pattern, they could go to 72mm Max Big Bore. For the 550F Reed Fed Cylinder to work, you would have to machine the Case on one side and Add a Block of Material to make the Side Port. It's not big, been a while since I measured a 550F case, but say 2" wide x 3/4" thick and maybe 2 1/2" long Block Welded on Case, then Machine Port to Match the 550F Case Port. Provision 8 Data is the same on all Rotax's. The American 250 that was Sold here never had the Pro8 Boss's a Threaded Holes. The 250 made over there has the (8) Bosses and (4) Threaded Holes, but from the Small Photo's they post, (2) Holes don't look Correctly Placed. Some DXF CAD Files for some Rotax UL Motors is here, only a Front PTO View and only one side View. Just scroll down to "2-stroke ROTAX Aircraft Engines" 447 or 503 and you will see the Provision 8 Spec's for the Gear Drives. The Skidoo/Rotax 670 Twin was the last Provion 8 Engine Sold here in the USA. The bottom half of the 550F's Sold here have the Bottom Boss's, but the Top Boss's have been Doctored. http://www.aviagamma.ru/draw-e.html Top View of USA 550F Case, you can see the Side Port you need to add to the Piston Port Engines. Also Front View of USA 550F, you can see the Pro8 Boss's on bottom, Top has been altered. Also, a 670 Case machined for Provision 8 Data. Pro8 is based off (12) 8mm Bolt Pattern, each Hole is 30 Degrees apart. #### Attachments • 39.3 KB Views: 5 • 54 KB Views: 6 • 27.5 KB Views: 6 Last edited: #### Armilite ##### Well-Known Member #### Attachments • 43.2 KB Views: 5 • 77.9 KB Views: 6 • 179.4 KB Views: 8 #### Armilite ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf For the 550F Reed Fed Cylinder Conversion, you have to cut a Slot in the side of Case and Weld on a Block of Aluminium for the Side Port. Something like this. I drew it straight, but it's really angled inward. Best way is just lay a 550F Gasket on Case and Trace around it with a Sharpie and then add metal. You could probably even Epoxy Glue it on, but Welding would be Best. #### Attachments • 11.6 KB Views: 2 • 17.2 KB Views: 2 #### pictsidhe ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf What is the pcd of provision 8 and is there a centreing boss? #### Armilite ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf What is the pcd of provision 8 and is there a centreing boss? ================================================================== What does PCD mean? Is it Parameter Circle Diameter? If so, they usually call it BC for Bolt Circle. The Bolt Circle goes through the middle of the Bolt Hole. This is a nice Bolt Hole Calc in Inches I like best. It lets you Output Unit Precision, I use 4 Numbers. You can Copy and Paste for CNC G-Code. http://theoreticalmachinist.com/BoltCircleCalc Another Bolt Hole Calc IN/MM. https://littlemachineshop.com/mobile/bolt_circle.php Another in In. http://www.doov.com/cgi-bin/bolthole.cgi?d=76&num=16&xoffset=0&yoffset=0&angleoffset=0&bolthole=Calculate Your Centerline of the Crank is your X/Y for your Provision 8 Bolt Pattern, the Centerline of your Engines Cylinder Bore is your X/Y Centerline. So for Provision 8 the Bolt Pattern is Based off a 100mm Bolt Circle. It's based off a 12 Bolt Pattern, but they only use 8 of them. Refer to my earlier post, they just don't use the ones in Red. Rotax use's mainly 8mm Studs/Bolts on most of the their Engines. Most Bolt patterns are concentrict to keep even Torque on the Bolts. Skidoo/Rotax Head/Cylinder Bolt Patterns mainly used are: (4) Bolt 94mm 45 degree 377/377UL, 380F, 440/447UL. (6) Bolt 94mm 30 degree Most of the Small CC Liquid Cooled 462, 470. ------------------------------- (4) Bolt 100mm 45 Degree Most of the Old 247-340F Singles, 503F, 550F. (6) Bolt 100mm 30 Degree All of the Liquid Cooled 521-670. ------------------------------- I don't have any Newer Bigger Bore Engines to measure. But most use: (6) Bolt I think 104-106mm 30 Degree. Most of the Liquid Cooled 600+cc. #### pictsidhe ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf PCD: pitch circle diameter. What you call bolt circle diameter, but not just for bolts. #### Armilite ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf PCD: pitch circle diameter. What you call bolt circle diameter, but not just for bolts. Ok, never heard that term PCD. On some things, they do use (2) different Bolt Patterns overlapped. #### rotax618 ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf This is my drawing of a Rotax C or E gearbox adaptor to Suzuki G series engine, sorry the CAD to jpeg conversion makes it a bit difficult to read. Don’t know how to post a PDF. #### Attachments • 101.8 KB Views: 8 • 46.1 KB Views: 14 #### Armilite ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf This is my drawing of a Rotax C or E gearbox adaptor to Suzuki G series engine, sorry the CAD to jpeg conversion makes it a bit difficult to read. Don’t know how to post a PDF. Ever make an Adapter Plate for a Subaru or Mazda RX7 13B? #### rotax618 ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf I don’t know how much power the Rotax gearbox could absorb, but I fitted it to a G10, 3 cylinder Suzuki. The starter on the E gearbox could actuallu start the Suzuki, so it was a nice compact conversion. I didn’t use this layout, the engine was tilted at 70deg towards the exhaust and the gearbox was vertical to get the highest thrust line. At 70 deg, oil from the rocker cover was able to drain back to the modified sump without an external tube, and there was room above the engine for a Bing CV carb. I did some extensive testing but never fitted it to an airframe. #### pictsidhe ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf This is my drawing of a Rotax C or E gearbox adaptor to Suzuki G series engine, sorry the CAD to jpeg conversion makes it a bit difficult to read. Don’t know how to post a PDF. Click 'go advanced' then click the little paper clip. I think the most powerful engine that Rotax fitted the C and E boxes to as standard was the 55ftlb 582. It's possible that there is some unused potential. I have heard of folks fitting them to RX1 Yamahas, with some failures. i think that they are about 90ftlb. #### rotax618 ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf I had a Rotax 618 with an E gearbox and was going to replace it with the Suzuki, the Suzuki was not standard and turned the prop at the same revs as the 618, but building a new engine mount and cowl proved too much trouble so when the 618 wore out I replaced it with a 912S. #### rotax618 ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf These are the same sketches in PDF, hope they are more readable. #### Attachments • 56.6 KB Views: 13 • 79.5 KB Views: 8 #### Armilite ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf Click 'go advanced' then click the little paper clip. I think the most powerful engine that Rotax fitted the C and E boxes to as standard was the 55ftlb 582. It's possible that there is some unused potential. I have heard of folks fitting them to RX1 Yamahas, with some failures. i think that they are about 90ftlb. ==================================================================== Duh, Rotax 618UL(73.4hp) C & E also used on 94hp Rotax Rick 670, 100hp BMW, 150hp Subaru, etc. C & E Gear Drives are good up to at least 160hp. I have never seen a B Drive used on more than a 582UL 65hp. IF, you upgraded the B Drive to the New Hybrid Bearings, Steel Races with Ceramic Balls and used the Full Synthetic Oil, I wouldn't be afraid to use it up to 80hp using Max 6500rpm. #### Armilite ##### Well-Known Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf These are the same sketches in PDF, hope they are more readable. I think that has also been 3D Modeled on www.Grabcad.com which would Save Time drawing it into CAD. #### Caltard13 ##### Member Re: 2 stroke direct injection engines conversions or ready available ones for aircraf Ok guys, I am certainly no engine guru. I'm trying to figure out what this is. its the engine they are powering the Mosquito XE285 with. They call it the Innovative 8000. but no mention of the maker. their websitere says "is a piston powered, water cooled, oil injected, fuel injected, electronic programmable ignition, 800 cc, 85HP experimental helicopter. on their website they seem to indicate it is Aussie developed, but I'm wondering if they are starting with the arctic cat 8000? further research on my part indicates it is NOT based on the Rotax, but is in fact the arctic cat engine, but it is identified as an Inntec 800. less that$3000 for a new one, wow.

I'm having trouble tracking down any good info - which is usually a bad sign.
anyone have any knowledge, experience or guesses?

thanks

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#### Armilite

##### Well-Known Member
Re: 2 stroke direct injection engines conversions or ready available ones for aircraf

Ok guys,
I am certainly no engine guru. I'm trying to figure out what this is. its the engine they are powering the Mosquito XE285 with. They call it the
Innovative 8000. but no mention of the maker. their websitere says
"is a piston powered, water cooled, oil injected, fuel injected, electronic programmable ignition, 800 cc, 85HP experimental helicopter.
on their website they seem to indicate it is Aussie developed, but I'm wondering if they are starting with the arctic cat 8000? further research on my part indicates it is NOT based on the Rotax, but is in fact the arctic cat engine, but it is identified as an Inntec 800. less that \$3000 for a new one, wow.

I'm having trouble tracking down any good info - which is usually a bad sign.
anyone have any knowledge, experience or guesses?

thanks
==================================================

That's an Arctic Cat 800cc 2 Stroke with a Custom Tuned Pipe.

"The Mosquito XE285 is powered by a water cooled Inntec 800 engine with 62kw (85HP). The Inntec 800 is a 2 cylinder, 2-cycle engine with fuel- and oil injection."

I didn't see at what Rpm it's rated 85hp. Skidoo made an 800 that was [email protected] and a 800HO that was [email protected]

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