Rotax 377?

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Tuneturkey

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What can you do with a Rotax 377 that was intended to be used on an ultralight with a belt redrive remote from the engine? The crankshaft has a coupler for an extension shaft. Evidently, the engine was not designed to be fitted with a standard gearbox like most Rotax engines, at least there are no obvious bolt holes, etc., for attachment of a gearbox. Would like to use as a 2 stroke backup for a 1/2 VW which weighs many more pounds with lower HP output.
Thanks
 

Armilite

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Sell it or use the Cylinders & Heads on a Newer Provision 8, 1993+ 377/380 Case. If you have an Airframe that Hangs the Engine Upside Down, not many of them around today you could use one of them Old Belt Drive.

With a CR Upgrade to 11.2cr, a Good Tuned Pipe for 6500rpm, you can make 52hp with a 377.
 

Tuneturkey

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Sell it or use the Cylinders & Heads on a Newer Provision 8, 1993+ 377/380 Case. If you have an Airframe that Hangs the Engine Upside Down, not many of them around today you could use one of them Old Belt Drive.

With a CR Upgrade to 11.2cr, a Good Tuned Pipe for 6500rpm, you can make 52hp with a 377.
Thanks for the comments, but help me out here. What is "CR"? I would be happy to just get 35 hp out of the 377, with a case that is compatible with current gearboxs.
 

akwrencher

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Thanks for the comments, but help me out here. What is "CR"? I would be happy to just get 35 hp out of the 377, with a case that is compatible with current gearboxs.
Compression Ratio. Keep it stock. There are ways to mount redrives on non provision cases, but it does limit your options compared to provision casses. Provision cases have provisions for mounting gear drive, i.e. pro 4 or pro 8 depending on the number of holes.
 

Armilite

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Compression Ratio. Keep it stock. There are ways to mount redrives on non provision cases, but it does limit your options compared to provision casses. Provision cases have provisions for mounting gear drive, i.e. pro 4 or pro 8 depending on the number of holes.
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There probably hasn't been anyone making a Non-Provision Belt Drive for probably 20+ Years. You can Buy a Good used Provision 8, 377/380/440/447 Case with a Crank off eBay for $150. Almost all 1993+ Rotaxs have a Pro8 Case till they were discontinued, the 277F and 380F/440F was I think discontinued in 2008, the 503F was discontinued in 2003. If you shop around you can find used Rotax B Gear Drives for $250-$550. I bought one 2.58 Ratio for $225 off eBay 6 months ago. It's usually cheaper to just find a Motor/Drive combo.

If you just want 35hp leave it Stock, if you want a little more HP, the 377/380 uses a low 9.6cr, and a bump up to 11.6cr is still good for 91 Octane, the 277UL used 11.8cr, so a CR bump would make you around 4hp extra. That 377UL, 35hp@6500rpm rating was with a Single Bing 54, 36mm Carb. Going Dual Carb would make you 2-4hp extra.
 
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