Steps to scratch build a VW

Discussion in 'Hangar Flying' started by Little Scrapper, Aug 13, 2019.

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  1. Aug 13, 2019 #1

    Little Scrapper

    Little Scrapper

    Little Scrapper

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    Looking for advice, especially from people who have done it.

    I'd like to build a VW engine from scratch and I need to amp up my learning. What are the current best resources for building one from scratch? Books, videos, article etc. I've build various small block Chevy's and motorcycle engines but never a VW and especially for a airplane. Looking for the best place to start my learning curve. As an example, do people buy new engine blocks? Used?and where to get them etc. Cranks? Same thing.

    I know I can order a engine done and I know it would be best and cheaper etc. I'm not interested in that, I'm interested in physically going through the process and learning.

    Appreciate any help.
     
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  2. Aug 13, 2019 #2

    akwrencher

    akwrencher

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    Are you wanting to do all machining and stuff too, or mainly assembly? GPAS sells parts and kits, basically a one stop shopping for aviation quality parts to build your own. I would start there, and I'm am engine guy. FWIW, I've only done a VW for an old bus, so no aero exp.
     
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  3. Aug 13, 2019 #3

    TFF

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    I would go buy a cheap VW engine and take it apart and put it together and just make it run. Trial run. You are not going to have problems. Just acclimation. If it just so happens to come in a car, drive it.
     
  4. Aug 13, 2019 #4

    fly2kads

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    I'm looking forward to the input from certain VW-savvy forum members, but here is my two cents:

    Books: the Great Plains assembly manual, and Tom Wilson's "How to Rebuild Your Volkswagen Air-Cooled Engine." I successfully rebuilt my first VW (ground-bound) engine using Wilson's book, and I didn't have prior experience with anything besides R/C engines and lawn mowers.

    Web sites: The Samba (https://www.thesamba.com/vw/) is a great resource for general VW knowledge. The search function is a great way to get questions answered, particularly in the Performance/Engines/Transmissions forum. There is also some good discussion in the engine forum on Sonerai.net (http://www.sonerai.net/smf/).

    Vendors: There are several good VW shops, but my go-to place for engine parts is Aircooled.net. (http://www.aircooled.net/)

    I won't start an airplane project until I complete the restoration of my 1966 Beetle (next spring...maybe?). There is a 98 percent chance that whatever I choose will be VW-powered. I am planning on building my own engine, just because I like doing it.

    Most of the advice I have seen is to start with a new case and crank, and I think that makes sense for most people.

    The Great Plains assembly kits seem to be a good middle ground between turn-key, assembled engines and the full DIY mode.

    Scrapper, have you determined what size of engine you want to build?
     
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  5. Aug 13, 2019 #5

    don january

    don january

    don january

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    I agree with TFF. I've taken a used VW engine and took it down to the crank and reassembled then studied the Hoover mods and dove into that area of cooling along with cleaning slag and airflow thru the fins. The KRNET site covers many areas of the VW power plant along with Corvair. I think the main factor of a VW for aircraft is NOT to try and get more out of the little engine that could!
     

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  6. Aug 13, 2019 #6

    Hot Wings

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    My advice would be - don't try. Seen way too much time, money and parts wasted. VW's are not anywhere close to Chevy/Ford.

    But since you want to try Start here:
    http://bobhooversblog.blogspot.com/

    And buy a new case.
     
  7. Aug 13, 2019 #7

    Little Scrapper

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    I have not because I haven't quite figured out which version is the most reliable. Steve Wittman flipped his VW around so I'm trying to figure out how that plays out etc. I a lot to learn so just trying to read and study each night before bed. Any here advice is welcome of course
     
  8. Aug 13, 2019 #8

    Little Scrapper

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    Sounds like good advice to me. I'll check it out.
     
  9. Aug 13, 2019 #9

    Little Scrapper

    Little Scrapper

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    I'm not worried about the money, I'm pretty careful and patient. I'm after the experience here. I'll check out those links. Thanks
     
  10. Aug 13, 2019 #10

    Little Scrapper

    Little Scrapper

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    I'll buy it with the machine work done, I still would like to read and understand what machine work is done though. If I'm gonna fly behind it I want to have a relationship with the engine so to speak.
     
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  11. Aug 13, 2019 #11

    Vigilant1

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    Published guides: I think the best single source for what you are describing is the GPAS manual and accompanying DVD on how to build a VW-based aero engine. The only two significant things I'd think would be advantageous beyond that would be:
    1) Bob Hoover's write-up on his HVX modifications.
    2) Everything Pops has written on this forum regarding building VW engines. We had a thread or two recently specifically about building VWs, engine displacement options, etc. I'll edit this post with links if I find them.

    Edited to add:
    A) Thread on Hoover HVX Modifications, with link to Bob Hoover's blog: https://www.homebuiltairplanes.com/forums/threads/bob-hoovers-hvx-vw-engine-mods.31359/
    B) Recent general discussion on building VW engines: (5 pages) https://www.homebuiltairplanes.com/forums/threads/build-your-own-vw-engine.30777/J
    C) Just Talking About VWs (18 pages): https://www.homebuiltairplanes.com/forums/threads/just-talking-about-vws.29535/

    Parts: GPAS is a great one-stop shop for parts you can count on. I do think it is >possible< to build up a reliable VW aircraft engine for less money by going direct to suppliers used by VW performance auto engine builders, BUT you have to know "good" from "junk" and sometimes the differences are subtle. Even the minor things (e.g. pushrod tubes, etc) can lead to problems if the wrong ones are chosen or they are installed incorrectly, but >someone< already knows which brands you should use annd how they should be fitted.

    The good news is that this is a very well-beaten path, and there's no need to do any experimenting. Craftsmanship and attention to detail are WAY more important than creativity in this endeavor. And, yes, accept the engine for what it is--maybe the best bang-for-the-buck airplane engine in the 40-75 HP range. Don't ask it for more power than it can reliably produce, baffle it appropriately, keep the CHTs in check, and have fun.

    Good luck
     
    Last edited: Aug 13, 2019
  12. Aug 13, 2019 #12

    radfordc

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    How to Rebuild Your Volkswagen Air-cooled Engine by Tom Wilson. IMG_20190813_123449602.jpg
     
  13. Aug 13, 2019 #13

    Little Scrapper

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    Ordered these two just now, should arrive tomorrow. This will be my reading over vacation in Florida which starts this weekend. Looking forward to studying.

    What about a case from Scott Cassler? From what I understand owner of GPAS passed away, I may be confused though.

    Screenshot_20190813-131033~2.png
     
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  14. Aug 13, 2019 #14

    Vigilant1

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    Bob Bennett, founder of GPAS, did pass away a couplele of years ago, and he is missed. GPAS has changed hands, and has spun-off some of their business lines (e.g brakes, etc). But they are still up and selling materials, and I still trust them. In fact, they are the only source for the great Force One prop hub and bearing-- Scott Casler buys that part from them. But you could buy parts from Scott, too. His finished engines have a good reputation, as does he.
     
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  15. Aug 13, 2019 #15

    Hephaestus

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    I'm curious about the don't try to make more power comment.

    What are reasonable power expectations out of the various build options? Because it sure looks like to a non vw guy there's 1.4L to 2.8L builds... 36hp to 80hp makes for some solid confusion ;)
     
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  16. Aug 13, 2019 #16

    Little Scrapper

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    Seems to me, based on my recent reading, the 2180 is very very common nowadays. That may Indicate something.
     
  17. Aug 13, 2019 #17

    Vigilant1

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    IMO, the GPAS guidance is reasonable. These are all 8:1 CR
    CC Takeoff HP Continuous HP (3400 RPM)
    1600......55..................50
    1700......60..................55
    1835......65..................60
    1915......69..................65
    2180......76..................70
    2276......80..................76

    The limiting factor at higher HP is the ability of the head to shed the required heat. It needn't be big problem if the baffling is good, and these are about the same HP/displacement as we see with Lycomings and Continentals. But, for whatever reason, folks seem to want to run them at higher CRs etc. Then, they get hot and things go wrong and somebody goes online and screams about the unreliability of the VW Type 1 engine. In addition to head/valve problems due to heat, if we ask for a lot of HP the bearing saddles in the (magnesium) case get pounded hard and then things aren't aligned right anymore.
    They are fine engines if the limits are respected, the valves are periodically adjusted, and the oil is changed. They do require attention--they are from the days when people worked on their cars and didn't mind adjusting valves, etc. Good quality parts are inexpensive.

    I've never heard of a 2800 cc Type 1 VW.
     
    Last edited: Aug 13, 2019
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  18. Aug 13, 2019 #18

    plncraze

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    RS Hoover said that all VWs no matter the size are limited by exhaust valve size. Horsepower is a good question. Stan Hall tried to get good numbers a long time ago and couldn't find any besides the factory.
    what is your budget for an engine?
     
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  19. Aug 13, 2019 #19

    Vigilant1

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    Yes, 2180cc is very common (that's the displacement for the Sonex Aerovee engine). Also, as Pops says, the 1835cc engine provides a lot of bang for the buck if you can get by with 60 HP continuous. The 1835 is the largest displacement that uses the stock 69mm stroke, when you go larger than this stroke for a "pulley-drive" engine most builders recommend using the Force One prop hub and bearing, which does add some machine shop time and some parts expense.

    FWIW, the engines do not seem to mind being run at higher RPM (after all, in the car they ran up to 4500 RPM IIRC), as long as the power levels are reasonable so the heads don't get overheated.
     
    Last edited: Aug 13, 2019
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  20. Aug 13, 2019 #20

    N804RV

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    Building from scratch, you're gonna need some specialized machining on the case and crank. Unless you're going to reinvent the wheel, you'll end up buying a fair amount of parts from one of the VW aero-conversion shops anyway. The kit engines are pretty complete and all the modification is pretty much done.

    You might be able to save money by finding a good deal on a used Great Plains or Revmaster engine for sale and overhaul it yourself. But, if you're not already an experienced VW engine guy, you're liable to wind up spending money on education that you wouldn't have spent if you went with a kit anyway. -JMHO
     
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