Engine Weight: VW versus Jabiru

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ChuckerF14

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Nov 1, 2013
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We all know that the aluminum VW engine case is about 24 pounds heavier than the magnesium case. The Jabiru uses the heavier aluminum. They both use iron barrels and aluminum heads. So why is a full-up Jabiru engine 25 pounds lighter than a similarly equipped VW? Where do they save 25 pounds of weight and how do they make up for an engine case made of heavier material than the V-dub? I'm baffled.
 

Flyguyeddy

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Central illinois
What case are you referring to, cause my modded wasser aluminum case (factory vw alum case) is 12 lbs more than a universal mexican case
 

ChuckerF14

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Maybe I'm mistaken about the details....but the aluminum case is definitely heavier. I've never had the chance to weigh one.

I just don't get why the Jabiru is so much lighter when the design and materials are so similar and they pay a penalty for an aluminum case.
 

ChuckerF14

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That explains it. I heard from a Jabiru owner that they were not aluminum. After your post I did a search and confirmed what you said. I still wonder how they make up for the heavier case material.
 

10kDA

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Aug 12, 2015
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I found out some of the early Jabirus had iron cylinders. I wonder if their newer claimed weight with aluminum cylinders was being applied to the older models with iron? You know how it is with airplane stuff - sometimes the weights are measured at the sales brochure or web page. Just saying... LOL
 

eschrom

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Jan 18, 2006
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Manchester, PA
Back when Great Plains sold nikasil cylinders they advertised a 10-lb weight reduction over iron. If that's true then the remaining difference with the Jab is 15 pounds and I'd almost bet a big chunk of it is in the crankshaft. Not sure how Revmaster or Aerovee stack up but my GP crank is a behemoth. With modern design tools like FEA Jabiru probably figured out how to make it lighter. That's my guess anyway.

Ed
 
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