What Engine basics

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Nev25

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May 10, 2007
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Victoria Australia
While looking to build a VW engine for a future build I approached a local VW enthusiast
Only to be confronted with questions like
Size, Single or duel Port etc

I can assume size is a dependent on aircraft
But Ports????
What else is a criteria

Is there a conversion chart somewhere CC to HP

Also I read somewhere that parts need to be changed (conrods etc) as a Aero engine is under constant load
an Automotive isnt

What needs to be changes
 

Vigilant1

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There's a lot to doing this right, and all the lessons have been learned the hard way by people before you over the last 40+ years. If you take advantage of what is already known and stay on the well-trodden path, you'll end up with a reliable, cheap-to-run aircraft engine. If you treat it like a car engine rebuild, it will be very unlikely to be successful. Some of the things needed to make a reliable airplane engine are different from the steps needed to build a good car powerplant.

A good place to start is the web site (Welcome to Great Plains Aircraft! )and catalog ( Great Plains Aircraft 2012 Catalog ) for Great Plains Aircraft Supply. You'll find charts in the catalog that give approximate HP for the various engine sizes (and compression ratios). It will also cover options for igntions, for fuel induction, etc. Lots of free info there. Steve Bennett (the owner of Great Plains) has been building VW airplane engines for years and is well respected. He sells primarily regular "float" carburetirs, and these work very well for users. Other options include "floatless" carbs available from Sonex ("Aerovonversions") --their "AeroInjector" and Revmaster (their "RevFlow" carb).

I'm sure a builder from OZ will chime in soon with a local source of aircraft VW expertise.
 

akwrencher

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Gustavus, AK
Check out the threads in this section. Lots of VW details have been hashed out here, and the answers to many of your questions could be just a few clicks away:)
 

akwrencher

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Also I read somewhere that parts need to be changed (conrods etc) as a Aero engine is under constant load
an Automotive isnt

This is true more true for larger water cooled auto engines. Anyone who has every driven an old VW bus knows this:)

HOWEVER, good aircraft conversions do change many parts out to increase reliability. The more hp you need to get, the more parts get changed. As posted above, Great Planes Aircraft website is a Great place to start
:gig:
 

Pops

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Jan 1, 2013
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You didn't say what airframe you want to install the VW engine into. That will be a difference on what size (cc) and HP engine you will want to build. The bigger the engine and more HP you will be demanding from it, the more different the build will be. Most mistakes are made form demanding more HP (Heat) than the engine can handle. I think that the most bang for the buck,( HP for $) and the most reliable is a 60-65 hp, 1835-1914 cc engine. A good stock crank, stock rods, 92 or 94 mm pistons and jugs, Single port heads ( if cruise rpm is to be below 3000 rpm). Longer, lower pitch prop on a draggy airframe. ( Fisher Super Koala)
For a Fast, low drag airframe, KR-2, etc. It will be a different built engine. Then dual port heads for the higher cruise rpm, with the shorter higher pitch prop, etc.
Dan


Added -- Steve at Great Plains will steer you in the right direction.
 
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