Steps to scratch build a VW

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

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  1. Aug 26, 2019 #321

    AdrianS

    AdrianS

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    But the Harley was designed in about 1903...
     
  2. Aug 26, 2019 #322

    Pops

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    If you don't check your oil no amount would be enough. The VW engineers designed the Type1 engine so when you change oil and clean the oil bath air cleaner, take 3 qts of oil and fill the air cleaner to the mark and then put the rest of the 3 qts in the engine. The amount of oil in the engine sump has never been a oil problem in the VW engine. If its a problem the cause of the problem is the operator. The only oil problem is the heads will not cool anymore that about 70-75 continuous HP.
    There again its the operator demanding more than that the engine was designed for. Fly behind a Lyc or Cont and never check the oil and you will have oil problems.
     
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  3. Aug 26, 2019 #323

    dmar836

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    First, I would would want proof I’m always running hot. Why add the couple pounds of oil and the larger pan unless I knew I was already battling heat? That’s just additional load on the engine and exacerbating the problem.
    My first answer to a problem is if I go back and simplify will I reduce the need for what I’m currently dealing with? So no need to add weight, complexity, and more heat until you know you have an overheating problem. Often checking baffling first or, even more to the point, removing some things will free up air flow, reduce weight and thereby reduce the load that produces the heat in the first place might mean there is no longer an issue. I have seen no final convincing argument, for example, that a full flow oil system is needed in my VW engine. My 0-300 never had one and it’s over 70 yrs old. Another way to look at simplifying designs is to ask if something’s actually needed to fly and land the airplane. If not then maybe it isn’t needed in the first place - redundant systems, extra batteries, full flow oil with additional valves, etc. Even flaps, if left retracted, can be a non-failing item regardless of complicated linkages. I know some guys leave flaps out of checklists due to the fact they aren’t required to fly and land the plane safely. I check them if I’m going to use them as just one functioning will kill me or my wife before we figure it out. If I had their mindset with a homebuilt I’d save the weight and leave them out. Maybe all these are left in place, of course, but don’t add indicators, extra gauges, multiple buss bars, or other additions that complicate a lot in order to convenience a little. Failures of such end up causing a lot of complications for the loss of minimal convenience. No wiring in the cabin = no electrical fire in the cabin.
    Dave
     
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  4. Aug 26, 2019 #324

    fly2kads

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    To elaborate on Pop's comments on the deep sump, here is what the folks at Aircooled.net have to say about them:
    Contrary to what a lot of guys will tell you, deep sumps do not offer additional cooling, their purpose is for a steady supply of oil for the pump to supply to the bearings. If the pump starts sucking air the bearings do not last long!
    The concern addressed by the deep sump is running at high RPM, which causes the gear-driven oil pump to move a lot more oil. It's possible, at high RPM, to suck oil from the stock sump faster than it can drain back in. You have to spin it up pretty fast for that to happen, and we're not approaching those RPMs in our application.
    (From: http://vwparts.aircooled.net/3-5-Quart-Thin-Line-Deep-Sump-Type-1-Based-Engine-p/00-9143-0.htm)
     
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  5. Aug 26, 2019 #325

    karmarepair

    karmarepair

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    It's a Texas Parasol. Riveted aluminum square(?) tubing fuselage, I forget how the wings went together. Mr. Lamb drew the plans in CAD, based on his mentor's "TLAR" design, and offered them up on the internet for free. Not a true ultralight with a full VW, but it's a pretty light airframe.
     
  6. Aug 26, 2019 #326

    karmarepair

    karmarepair

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    While I agree with you about the oil screen being inadequate (not all do, see below, and other posters), there are some problems with that filter adapter. I quote Veeduber (R.S. Hoover):
    "this type of pump cover was developed some years ago for the 'kiddie trade,' allowing youngsters to install an oil filter (and external cooler, if desired) without having to do any machine work on the crankcase. The method was never used on any professionally built engines that I know of for four pretty good reasons: The oil passages in the pump cover were small, restricting flow at full throttle, there was no provision for a pop-off valve, subjecting the filter canister and cooler core to pressures as high as 300 psi during a cold start, the inlet & outlet ports were separated by only a narrow land -- less than sixth thou as I recall -- the gasket of which had a habit of failing during a cold start, and -- perhaps worst of all -- the thing was made of cast aluminum.

    Most miss this last point because nowadays cast aluminum pump covers are enormously popular. Unfortunately, aluminum doesn't wear very well and the pump's steel gears will quickly grind a neat pair of circular craters in such covers. Since the end-clearance spec is only .002" as soon as that opens up you'd see a precipitous drop in both pressure and flow."

    If my engine ever gets finished, it will have a STEEL oil pump cover, and will be drilled and tapped for a full flow filter.

    Changing your oil every X hours, where X is a small number, will help those who don't care for the extra plumbing (and weight!) of a proper full flow filtration system, but in the event of a SUDDEN breakdown (cam or lifter chunking, for example), filtration will keep the metal from circulating, and will keep the prop spinning a while longer, AS WELL AS increasing the longevity of the engine, but most homebuilts only fly a few hours a year, so I can respect the choices of those who do NOTHING.

    The lay down oil cooler adapter is a neat bit of kit, still available from GPASC.

    GPASC also has ALUMINUM intake manifolds - just the end pieces that bolt to the dual port heads, and have a SINGLE inlet, for you to form up your own pipe work down to the carb (Tillotson Model X in my case - Ford Model A replacement in pot metal vice the original Ford cast iron bit).
     
  7. Aug 26, 2019 #327

    blane.c

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    Put an oil quantity indicator in the engine, add a reserve oil tank, plumb a line from the reserve oil tank to the engine sump, install a pump and a pilot controlled switch in the line. Voilla' .
     
  8. Aug 26, 2019 #328

    lakeracer69

    lakeracer69

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    Last edited: Aug 26, 2019
  9. Aug 26, 2019 #329

    dmar836

    dmar836

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    Lol. Perfect!
     
  10. Aug 26, 2019 #330

    Pops

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    I welded a small alum oil sump of about 6 ounces and extend the pickup tube down to close to the bottom with a 45 deg cut on the end for one reason. I have had road race VW's where it was easy to unport the pickup tube in a turn. They make a tray that you can install in the engine to help but you have to tear the engine apart to install.
    Didn't want this to happen in a hard slip ( I live in the WV mountains with short runways and steep approaches). The small sump works with very little weight.

    I agree on the oil pump cover. The steel cover is far better. On the 1835cc engine on the SSSC I tried an aluminum cover with the pickup for the full flow oil system with a cooler and oil filter. Ran it a few hours and checked for ware from the gears. Had slight marks on the alum face. I had a steel oil pump cover with the full flow pickup and put it on. Large oil leak around the gasket. Check the pump cover on a thick piece of glass, had a .008 warp between each bolt hole. The stock gasket is only .004. Lots of VW junk on the market. So went back to the alum cover and checked it for anymore wear at the next 25 hr oil change and no change. So its still on the engine.
    The 1835cc engine burns about 3 ounces of oil in 25 hrs, so don't need any more capacity and zero oil temp problems.
    All the steel covers are heavy compared to the alum, but life of the engine is more important than a few ounces. Need to try this cover.
    http://www.piersideparts.net/GBE241.html

    Have own 3 straight tail C-172 and a couple thousand hours behind the Cont-0-300 engine. Great engines.
     
  11. Aug 26, 2019 #331

    dmar836

    dmar836

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    And about the perfect do-it-all plane. Those who have flown only later 172s don’t understand how great the straight tails are.
    Ours has original paint and is “polished”. Aged paint but flawless inside! My wife will sell me before her “Rosie”!
    Dave
     
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  12. Aug 26, 2019 #332

    Pops

    Pops

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    I have had 2- 1959's and 1 -- 1956 Cessna 172. Also have about thousand hours on 1977 and 1979 models. The straight tails are a far better flying airplane.
    Picture of a 1959 that I restored and in a museum in Germany.

    Now back to our regulator scheduled program about building VW's.

    995.jpg 994.jpg interior left side.jpg
     
  13. Aug 26, 2019 #333

    Vigilant1

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    Oil filters: IIRC, Bob Hoover thought they were important, at least for cars. Revmaster includes them on their aircraft VW engines, Sonex doesn't, and GPAS leaves it up to the builder. I don't know if Scott Casler includes them in all his builds, I didn't see them on his 1/2 VWs. VW didn't have them in their stock engines.
    It's a little more oil capacity, if installed other than "threads up" then they do cause a slightly longer delay before the oil gets to the bearings on startup, obviously they keep the oil cleaner, and they do result in a few more spots where oil can escape--slowly or all t once.
    Are there any opinions on the upgraded sump/SS filter that EMPI makes? It holds a little more oil and serves as a sump so it might help with short periods of oil slosh/intake unmasking, and the washable filter ("micron filter"--how >many< microns?) is probably finer than the stock wire screen, not as good as a pleated paper filter. Anyway, it doesn't introduce new places for leaks, and they say the oil keeps flowing if the filter gets clogged.
     
  14. Aug 26, 2019 #334

    cavelamb

    cavelamb

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    No, it was my last Texas Parasol project - but highly modified for the heavy engine.
    An additional 15 inch bay was added to the aft end of the fuselage.

    The airplane was built as an engine test bed for this engine.
    I had plans on using it in a faster machine later on.
    But that never came to pass.

    The design uses extruded aluminum angle (not tube) and driven rivets (not pops).

    The plans are available if you would like to study them...
    http://www.matronics.com/photoshare/cavelamb@earthlink.net.02.11.2006/index.html
     
  15. Aug 26, 2019 #335

    cavelamb

    cavelamb

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  16. Aug 26, 2019 #336

    Pops

    Pops

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    I always liked the Texas Parasol. That is my problem, I like more than I could ever build and fly. But, I love to see other people build the airplanes I like and enjoy.
     
    Last edited: Aug 26, 2019
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  17. Aug 27, 2019 #337

    cavelamb

    cavelamb

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    Yep. We (Bob and I) argued VW philosophy a lot back then.

    He could be really condecending when he wanted to be, and he had a way of expressing himself.

    But he never finished his engine.
     
  18. Aug 27, 2019 #338

    Little Scrapper

    Little Scrapper

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    I'm finally back from vacation and want to get started with the VW engine build with buying a new case.

    Question. Can the oil mods be done at home without too much trouble?

    I'd like to order a case and have the minimum machine work done. Align bore, cylinder etc. If I can do the oil work in my shop I prefer this. I've decided to build a flywheel end prop engine like Wittman did. So I don't need the force one machining.

    Anyone want to start that discussion before I order a case?

    Thanks
     
  19. Aug 27, 2019 #339

    Little Scrapper

    Little Scrapper

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    These are some screenshots of what I believe is the correct case to get from MOFOCO, which is local to me.

    Screenshot_20190827-080301~2.png

    Screenshot_20190827-080229~2.png

    Screenshot_20190827-080223~2.png
     
  20. Aug 27, 2019 #340

    lakeracer69

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    Unless you have all the NPT taps and correct drill bits, I don't think that you could do the full flow Mods cheaper. You're a plumber so maybe you have all that and the NPT plugs too.
     

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