Two seater, targa topped bus restoration (914)

Discussion in 'Restorations' started by mcswiggs, Feb 18, 2018.

  1. My WO 1700 has the sump baffle , its a fiddle ....you can increase CR with new Pistons and barrels if yours are Knackered if you wanted . The first thing I`d do is strip and clean those heads and check for cracks in the ports , they are extremely prone to over heating and cracking .....
     
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  2. 82B8B20F-23E5-4005-B365-8D821E8D3044.jpeg
    I don’t think this one has got swivel adjusters - I’m not at home to check but these look pretty solid... hopefully all the other 914 features are there. It really doesn’t look mucked about - until I came along that is.

    I think my mission here is to keep it as stock as possible - I know people will disagree, and there is some happy margin in VW’s original design, but it always seems to me if you alter one thing you need to compensate for it somewhere else, and right now I’d settle for getting it running at all rather than street tweaked.

    Agree with stripping the heads - check spring heights (the ones that were left for 20 years compressed are likely to have permanent set I think) and check the guides. Perhaps I could get away with lapping in some new valves and replacing the springs.
     
    Last edited: Apr 3, 2018
    77 Westy likes this.
  3. Duplicate post - editted and deleted!
     
    Last edited: Mar 27, 2018
  4. After a bit of research - that’s another difference between the 1700 and 2.0l, only the smaller engine got the 8mm swivel foot. The 2.0l (and probably the 1800) is the same as a bus, solid 10mm adjuster screw.

    Every day is a school day.:)
     
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  5. BBD81F1E-E173-47F4-9233-36901EA2B93E.jpeg 6C0889B6-A08C-4B05-82B4-87DCD3E1EBA4.jpeg 804295D8-CAB1-473B-9849-14B5C98A3610.jpeg 898C2ED9-8466-4452-8CDC-3D8062EA338B.jpeg C7D837FF-7F80-40C6-97FB-06ED15D6F9D0.jpeg Spent the bank holiday cleaning up the heads. No sign of any cracks and the valve seats are where they should be. Yay!

    I did the Wilson wobbliness tests on the valves in the guides - they are mostly very good, the very worst one is about 0.7mm of wobble (0.46 is at new, 0.9 is ‘worn’) so to my mind it’s only half way worn. I read @Deefer66 ’s excellent rebuild thread and I’m not sure I want to tackle a valve guide job not least because I don’t have the means to cut the seat in line with the new guide. Given it will be at least 5 years of driving before I put 10k miles on it I think it’ll be ok.

    As for the valves; they haven’t stretched and the stems aren’t worn. A couple have slight pitting on the rocker face. Really not sure what to do about replacing them. You can just see the putting in the photos. The racketeers known as Porsche will serve up a sodium exhaust valve for a mere $189 each. (This’ll be why stainless are more popular the - that, and solid stainless being stronger.)

    Can I buy direct replacement stainless valves? I might have misunderstood it, but the new valves seem to be rounded up to 8mm and 9mm for exhaust and inlet respectively thus needing corresponding new guides with all the oven/freezer action that goes with it.

    Fiddling with the heads is a useful distraction from worrying about that seized piston which remains stubbornly unmovable. The crank isn’t seized though, I can turn it a little as the stuck barrel rides with its piston for an inch or so of travel. I saw @paradox recommended pouring hot oil in the pot - I’ll have to try this next. Any more tips and suggestions welcomed.

    @77 Westy - you suggested whacking it with a soft hammer - if I’ve understood you correctly I aim the blows parallel to the crank and onto the barrel outer surface towards where the gudgeon pins are - is the right? Thanks!
     
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  6. Flakey

    Flakey Sponsor

    If you've got the oposing barrel off can you not get to the big end nuts on the seized pistons rod undo them and pull the barrel and piston out to deal with it on the bench?
     
  7. Didn't know the sodium valve stems were a different diameter!... You can get guides sleeved now, I think its a machine shops favorite option if you use them.. Would be cheaper than a set of sodium valves if you do need to replace... And thanks for the kind words...
     
  8. I was wondering that - but the stuck one is very near TDC, so the opposing one is too far sunk in to get at the gudgeon pin. Damn. Keeping’em coming though. FEE512C9-72C1-4967-A399-5A60A847C7A4.jpeg
     
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  9. Flakey

    Flakey Sponsor

    Can you lock the crank and tap the barrel of the stuck one back towards the case if you've got a little bit of movement , then you're not trying to tap on the fins?
     
    mcswiggs likes this.
  10. just a quick thought, as the coefficient of expansion of Aluminium and its alloys is roughly twice that of cast iron how about freezing it?
    If the ring is the stuck item it may do no good, then resort to the "hit it with a hammer and a block of wood" method.
    enjoying following this
    cheers
    Andy
     
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  11. Sodium filled valves dissipate heat better than stainless steel and while stainless is strong it’s relatively soft. Don’t try to re-face sodium valves or let anyone else try unless they know the risks.
    New valves from Ahnendorp B.A.S. if you need them. https://www.ahnendorp.com/VW-Type-4---Porsche-914-engineparts-and-machining/Valve-Sets-90/
    The weakest part of the piston is right in the middle of the crown, the edges are supported by the skirt and the strongest part is parallel to the crankshaft where the gudgeon pin boss is. But, the piston has clearance in the barrel and will tilt slightly and it might free off if you hit it at right angles to the crankshaft – first one side then the other, it’s only a few thou but might be enough. If that doesn’t work I’d use a round block of wood just smaller than the barrel and give the piston a good whack. Hot oil might help or you could use a blowlamp and give the piston some heat cycles.
     
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  12. Unfortunately the bolt heads are on the piston side of the rod – difficult to get at.
    That’s ^worth trying although I think it’s easier to hit the piston.
     
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  13. thinking further on the expansion theme, heating it up with a hot air gun or similar might just disturb the seized bits enough so that when they cool you may get a bit of movement, best of luck
    A
     
    mcswiggs likes this.
  14. Good idea, it’s probably the rings seized into the barrel but worth trying
     
  15. Lots of top advice, thanks guys.
    I think I’ve been confusing - the sodium valves are the same size as the normal ones used on busses - I’m just worried as to whether new valves just pop straight in or are they outsized and so need new guides. I don’t think they do, just need to double check.
    Ah yes, I discovered Ahnendorp a couple of days ago - they looked promising and it’s good to have a recommendation.

    Yes, I think I’ll try both locking flywheel (have to put it back on first) and tapping the barrel and putting a block on the piston and whacking that too (not at the same time, obvs).

    I’ll apply some heat too. I did put my steamer on it, but the whole thing is designed to dissipate heat so it’s difficult to actually get it hot. I might get away with putting the barrel and piston in the freezer if I could only get them off, but not much hope of being allowed to put the whole engine in there since the incident with the electroplating acid pickle and the Le Cruset pan.

    Probably be Saturday before I get back in the shed.
     
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  16. Well, that took most of the day but that stuck pot is finally off! I applied everybody’s suggestion - hot oil, hot air gun, a bit of sunshine, but most effectively a block of wood and hell of a lot of whacking. Millimetre by millimetre it slowly let go - needed an extra bolster underneath the pot when it got close to BDC. The good news is it wasn’t rusted, it was just the top ring was locked solid with crud and coke. The pots and pistons actually look pretty good but I can’t imagine after all that hammering I’ll get away with re using them. I’ll do some measuring next, but not going to get the opportunity for a few days.

    3397088A-40C6-48E7-9570-1DE13DF96A44.jpeg BB9F4D10-611D-4125-8BC5-3E50C37B9F0E.jpeg 88DEDCCB-C974-432D-B92F-35943A585B23.jpeg
     
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  17. I’d replace all valves if it were mine .
     
    mcswiggs likes this.
  18. With what, stainless steel? :thinking:
     
  19. Well done! Unless the barrels are scored they’ll clean up and with a hone to deglaze them they’ll be fine - probably. :)And they’ll be better quality than new ones. The piston too will probably be okay but you know how hard you hit it.;)
     
    mcswiggs likes this.
  20. Thanks, I do appreciate the encouragement.

    Wish I’d read this 20 mins earlier - just having a Sunday lie-in and my only contribution to the engine today has been to take advantage of VWH’s 15% discount on Mahle P&B sets before making my way to Wembley for the much anticipated, something-or-other trophy final between Lincoln City and Shrewsbury (come on you Imps - apologies to any Shrewsbury fans in the unlikely event of them reading this thread).

    I’m tempted - was going to replace two or three anyway. But at €360 for a set of sodium exhausts I’m thinking of the ss ones.
     

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