VW Engine Maintenance

Discussion in 'Volkswagen' started by dragon2knight, Aug 15, 2019.

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  1. Aug 15, 2019 #1

    dragon2knight

    dragon2knight

    dragon2knight

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    While I see tons of info regarding how to choose, build and install VW engines on this forum I'd love to know how to do basic/advanced maintenance on them. I know no one who has one so I can't ask there. This is an engine I've long admired but simply don't know what to expect to have to do, at what intervals to do it, and what I need to have handy to do all of that. I'm not an A&P, but am pretty comfortable around tools. Thanks :)
     
  2. Aug 15, 2019 #2

    Hephaestus

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    Mark Langford n56ml.com I think used to have some great articles - might be worth checking in with too...
     
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  3. Aug 15, 2019 #3

    delta

    delta

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    A lot of people recommend @ 25hrs... Check head torque, adjust valves, change oil, and check plug color. It pays to have an easy to remove cowl or acess panels.
     
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  4. Aug 15, 2019 #4

    fly2kads

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    Here is the maintenance schedule from Great Plains:
    http://www.greatplainsas.com/scmtce.html

    Most of the items on this list are standard automotive maintenance tasks, and there are "how-to's" available online, and in books like Muir's. Checking the mags should be similar to normal aviation practice. Other items, like checking the intake and exhaust systems, will vary according to the specifics of the installation.

    The task that a lot of people seem to have questions about is the periodic valve adjustment. There is a good description here:
    http://www.vw-resource.com/valveadj.html
    The Muir book covers it well, also. This is an important task in a VW, and should be done regularly. It's much easier to do than it would appear from the long description. Pops has mentioned keeping a log so he can spot trends, which I think is a great idea.
     
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  5. Aug 15, 2019 #5

    dragon2knight

    dragon2knight

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    Sounds great, didn't think it would mirror an automobile version so much, especially with all I've read about possible valve issues. Guess just adjusting (or at least checking) valves is good practice. Does look to be a bit of work keeping them going though....but I also guess that's the trade off for the low cost. Not really too different from 2 strokes in that regard really....thanks!
     
  6. Aug 15, 2019 #6

    Daleandee

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    When I bought my nose roller Sonex with the VW conversion I was told that if I didn't mind ongoing maintenance that the VW would serve me well. It is simply my opinion but the four stroke VW was a couple of worlds better than the Rotax 503's I flew for years. The two strokes are pretty good engines but they will punch out and go home early sometimes. The four stroke VW never left me searching for a field although the carb supplied by the manufacturer at that time left a lot to be desired and caused a couple of, shall we say, "precautionary" landings.

    The heads do take a beating in the big bore VWs that are asked to work hard. The Sonex is a good example of this (again IMHO). The engine will fly the airplane but on a warm day, a little density altitude, a passenger, maybe a little luggage and you will find the need to pick up your feet at the tree line as the head temps run for the red.

    Build a reasonable engine and use it in a reasonable air frame (see Pops) and you should be very well pleased and get some good time before the heads need work/replacing.

    I'm currently working with a young man that has a Legal Eagle with the Mosler CB40 engine on it (think 1/2 VW). Has the single mag and Zenith carb (IIRC) and runs well. Made a short hop down the runway the other day. If the weather will permit it may get some airtime this evening. The Mosler, so far, has been impressive.

    Dale
    N319WF
     
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  7. Aug 15, 2019 #7

    Pops

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    That is what I do. Never had a loose cylinder head nut or stud. I just make sure they are not running hot. Yep, adjust valve lash and record at the 25 hr and check plug color. If you have one that is a lot whiter that the rest, run the engine a squirt some WD-40 around the intake manifold for leaks, the rpm will increase if there is a leak where you sprayed.
    I have a spare set of heads that will be installed at between 400 -500 hrs and rebuilt with new valve guides and valves and have ready for the next swap.

    Back to the VW in the auto. I usually get about 150-170K of miles out of an engine for normal driving. I change oil (Valvoline Racing Oil ) every 3K miles and at 12K the mileage will be down from 32/33 for a 1600 cc engine to about 28/29 mpg. Time to change spark plugs, points and condenser and check plug wires. That will put the mileage back up to 32/33 for everything else is right, Timing, air pressure in tires, alignment, etc.
    Since I started using a Bug to drive to work in 1969, and usually put at least 50K a year on one, I would have a fresh overhauled engine setting on the workshop bench ready to swap out. Or when your 16 year old daughter is driving the VW camper Bus with leaky valve cover gasket and I tell her to check the oil before using. Nope, the oil light came on driving at night and she continued to drive the 20 miles home to ask me what was wrong. I could hear the bearing signing as she pulled in the driveway and when she turned the engine off it was froze :) Memories. She is 58 years old now and have flown behind 2 airplane engines she had majored.
     
  8. Aug 16, 2019 #8

    dragon2knight

    dragon2knight

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    Thanks for chiming in Pops, it's appreciated :)
    I've driven 2 '70 bugs for over 150000 miles each with nothing more than good maintenance as you described. I do trust the little buggers for sure....or at least I did. Not all of the parts are as good as they once were, the 009 distributor comes to mind. And I was only really into genuine VW heads...again, new ones are not really around anymore (MOFOCO not included in that). Lots of Chinese junk out there masquerading as a bargain....sigh...guess VW had to stop making Bug parts sometime I guess, glad they did it as long as they did as they certainly didn't have to. My only real concern with Aircraft versions is that some of said Chinese junk will find it's way into flying examples---hopefully not.
     
  9. Aug 16, 2019 #9

    Dana

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    I had a Mosler CB40 in my Fisher 404... yes it's more or less a half VW but the only actual VW parts are the pistons and cylinders, everything else is aftermarket. Good reliable engine, just a bit anemic for the plane it was in. I'll echo what Pops said... check the valves when you change the oil, use Valvoline Racing oil (or any oil that has zinc, which no street oils have any more as the zinc fries the catalytic converter in modern cars). Best to use a real Slick magneto, the surplus ones are cheap but they've been sitting on the shelf for a l-o-o-o-n-g time and the coils and condensers go bad with age. They're easy to work on, parts are cheap, and any auto shop can work on them if you need it (I had to get the valves ground at one point).
     
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  10. Aug 16, 2019 #10

    Hot Wings

    Hot Wings

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    The only things I'd add to what has been mentioned:
    Keep a log, or at least a mental note, of the hot and cold oil pressure at each oil change.
    Tug on the crank to check end play. You can feel .003" but shouldn't be able to see any movement.
    Cut the oil filter open and look at it. Check the magnet in the sump too.
     
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