Eagler's Nest
Engines => 2 Cylinder => 1/2 vw => Topic started by: Maxray on May 09, 2018, 01:14:22 AM
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Hi all,
Help!! I am building a LEXL #H-13 and am in the process of starting to purchase parts for the engine.
I own a AS21 block recently bored for 94mm Cylinders and is .020 over line bored. It has case savers installed. I have zero VW experience.
I am lost! My head is spinning with informational overload. I have a few questions that probably may have been answered before but I am
trying to narrow it down to the basics. At 61, I am trying not to waste money on parts I did not need or should not have bought.
I would truly appreciate any input from you veterans. This is my second aircraft build in 25 years and so much has been changed and improved.
I built a very nice Minimax in the early 90's.
I am going for 40-45 H.P. on this build and need to know:
- Which cylinders to buy. I like the idea of the Nakasil? cylinders but am lost as to shims, length and such..
- Which crank and cam to buy. I am guessing that I want an 82 or 86 stroker crank? Bearings?
- What size and types of Mikuni carbs?
- Pistons and rods. I have heard of Chevy rods being used but cannot find out if they are being used in any 1/2 VW builds.
- I am looking at heads on eBay on am not sure if this set will meet my needs... https://www.ebay.com/itm/131930025980 (https://www.ebay.com/itm/131930025980)
I plan on using Hummel engines for the machine work as Scott is the only shop I can find to do the work. I live in Northern Ohio
and have had no luck getting in touch with any Ohio LE builders.
I am an EAA member but nobody seems to know anything around here about 1/2 VW's here that I've asked.
Is there someone who would be interested in building my engine? I am too old to learn building one engine I am going to bet my life on with no experience
in these 1/2 VW's. I can do the machining, water jet, laser cutting and fabrication of any custom parts needed for the whole build. Just not the engine internals.
Thank you guys!
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Why not let Scott Casler build it for you? That is what I did. I was going to build it, but I decided that Scot does it every day , He knows how to build a safe 1/2 VW for aircraft use. Mine is a 45hp full case ( 86 mm stroke x 94mm nikasil jugs ) set up for a magnito ignition. The rods are chevy rods. I sent him my block and he did the rest. I also had Frank from Performance Props build my prop. I am very pleased with both the engine and the prop. :emoji_u1f601:
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You will not want to go over 84 MM on the crank. Any more and you will start having clearance problems with the case and cam.
Both type cylinders (nickies and cast iron) now come in "stroker" lengths so that you don't need shims, you just machine the bottom of the cylinder down to what ever deck height you have figured up to set your compression ratio...
You only want a German forged crank and cam gears --no Vw magazine hot rod parts.'
I am fairly certain Demello still produces the 1/2 Vdub forged German stroker animal.
Scott Cassler will put the thrust bearing on the nose of the crank where it belongs, plus balance it all to hell and back.
Also he has a special way to keep the end of rocker shaft stable -- no roll pins. He puts a bearing surface in the end of the valve cover galley...
(https://media.giphy.com/media/12AhYXbjRMGExi/giphy.gif)
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Hi guys,
Hey! I really appreciate the info... I would really like to have Scott do all the work if I can afford it.
Poorman, can you tell me roughly what you ended up at with having Scott do your work?
I am on a fixed income and I hope I can budget the work. Who doesn't Lol!
Sounds like I need the exact same work done. I did locate a stock set of used heads on a dual port
1600 I picked up yesterday for $150. It is an almost complete engine minus the cooling shrouds.
Dan, Demello has good prices for sure!
Thanks again,
Max
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if i were to build a half vw, this is how id build it. take this for a grain of salt and some of these options are expensive
-new case, as41, machined for 94mm cylinders, force one hub, and stroke of 84mm
-demello prepped and stroked wasserboxer 2.1 crankshaft
-revmaster long skirt cylinders
-"chevy" rods (you can get to 80mm stroke with just offset grinding for chevy rods on wasser crank)
-049 revmaster heads, non aviation grade (dont want the dual plug)
-dual 26mm mikunis
-maybe a small sump cup to get a little more oil
-all the hvx mods as shown on bob hoovers blog
-not sure on camshaft.
i wish i could use my wasser case for a half vw. it is clearanced from the factory for stroke, and has full flow oiling with a filter boss cast into the block. also holds 4qts of oil as stock. the damn thing weighs 30# after you cut the water jackets off (die cast aluminum german block)
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the thrust bearing at the nose is a good idea, and ive seen it done on a few hot rod vw engines on thesamba.
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Hi FlyguyFreddy,
Wow! those are all great suggestions I don't know how to locate the Bob Hoover blog or I would check it out for sure!
I would appreciate that link for sure.
I do have an AS21 case already bored for 94mm cylinders. I am not familiar with the sump cup as I have Zero VW experience.
I truly appreciate your input!!
Thank you,
Max
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http://bobhooversblog.blogspot.com/2007/05/hvx-mods.html?m=1 For the original writeup of these mods
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Thank you for that link!