Test run

Discussion in 'Mech Tech' started by Deefer66, Jun 17, 2016.

  1. Zed

    Zed Gradually getting grumpier

    And you did set some deck height?
    Seems odd that it's stiff at TDC with no plugs in. :thinking:
    As you say though, one man's tight engine could be another's normal new engine. But it shouldn't be making the starter smoke!
     
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  2. Zed

    Zed Gradually getting grumpier

    Just a thought... Oil ring is 3 piece. If you get the middle wavey bit overlapped wrong...
     
    Deefer66 likes this.
  3. Think so... best get some new gaskets in for the crushed ones!

    Pretty sure I checked but could have jumped in installation I suppose.

    Sent from my Hudl 2 using Tapatalk
     
  4. Zed

    Zed Gradually getting grumpier

    Yep, I'm clutching at straws.
     
    Deefer66 likes this.
  5. Me too...One last go at taking apart and putting together again! Then it's time to move on and get help to get on the road before the summers gone....

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  6. I've just read your engine build thread - I'm really willing you on now to get it going. You must be so close.

    Hopefully it is something silly and you'll laugh about it in months to come. I haven't yet had to pull my van motor and can't offer any useful advice, but for some encouragment I have rebuilt my RX8 engine and it took weeks to realise I'd got a light green and red wire and a green and red wire for the fuel injectors mixed up - as if blokes should be expected to know the difference between green and light green!

    Best of luck! It will be worth it when it's done.
     
    fafs likes this.
  7. Thanks.. a little encouragement goes a long way... that why I like it here.. mostly..





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  8. Well.. spins ok as a short motor..think it's a marginal gains thing or loses. Barrels seem to be a bit stiff at mid stroke not top and bottom as I thought. There was a bit of crud in there though..
    [​IMG]
    Heads made no difference.. springs on valves adds a bit more.. spark plugs more again..except I found this out backwards.

    Will have a look at how pistons slide in barrels tomorrow maybe Sunday. Perhaps those rings need a clean now.

    See if I can put it back together again and keep the increases in stiffness off!... then strap it to a bigger battery

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  9. Zed

    Zed Gradually getting grumpier

    I'm saying nothing. After 50 miles I pulled my 2020 and stripped it down like you have to look through the barrel holes and see the cam and followers were just fine. Lol
     
    Last edited: Jul 2, 2016
    Deefer66 likes this.
  10. As this is really the only vw related thread among a load of euro and other crap at the moment we are expecting lots of pics and updates .....

    I see you reused your barrels ....which is fine as they are good for hundreds of thousands of miles and probably better quality than new ....just checking as there will be a slight lip at the top that you raised the barrels off the case so the rings don't come in to contact with the lip ? Either by doubling up on the gasket or with shim ....

    I know you can get high torque starters but shouldn't be needed in your case
     
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  11. Zed

    Zed Gradually getting grumpier

    If you reuse the b&PS, you really need to get them back in the same place at the same distance from the crankshaft. I'd have taken the opportunity to replace them with bigger ones. :D
     
    Deefer66 likes this.
  12. ...no one mentioned that during the build! ... but seems to be moving ok at the extremities of stroke!... unless that's the collected crud! Stiffer right in the middle of stroke.

    Removed head shims as recommended but needed barrel shims (1mm) to get back "deck height" and CR.

    Didn't fancy spilling another 300 notes on B&P at the time but seems more attractive as time goes by! I'll clean em up again this morning and see how they slide!

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  13. Zed

    Zed Gradually getting grumpier

    The barrels are now 1mm further out and the pistons are still in the same place so the part of the barrels new to the rings is at the bottom of the stroke. Sorry I'm not experienced enough to advise. I did myself remove spacers under the barrels of my 1600 to increase the low compression ratio a bit and nothing bad happened. It's a risk that a ring will break but how big a risk depends on the wear. Like yourself I judged no obvious wear and went for it.
     
    Deefer66 likes this.
  14. 77 Westy

    77 Westy Supporter

    The highest piston speed is at mid stroke, at TDC and BDC the piston changes direction and the speed is low, so, without compression you’d expect the engine to be tightest between TDC and BDC - but nowhere near as tight as you’ve found.

    Did you check the cylinders were round (not oval) and the bores parallel (not barrel shaped) and did you hone the bores to remove glaze?

    That debris at the bottom of the cylinder has to have come from somewhere; I’d want to know where. I think you’re lucky the engine didn’t start.
     
  15. Without the spacer CR goes up from 8.3 to 9.2. but not noticeably harder at the part of the cycle where pistons are at the bottom.

    The only thing I can think is at mid stroke conrods are pulling at the greatest angle to the piston so pushing/pulling them in to the sides of barrels more
    [​IMG]
    Got to clean them up and get that dirko off now!
    But at least the lack of sealant on the shim shows it getting flat to the case!... small wins...
    [​IMG]
    Just hope it still does and seals their goes back

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  16. It wasn't managing high speed anywhere .... but yes should be higher speed there.
    Gave them a quick light hone but not enough to roughen them up.
    Going to clean out the ring groove an edit them in case there's crud under there holding them up!

    The oil rings sit on top of the lip on the springy ring don't they?
    It's the only way to get side clearance... so must do.
    [​IMG]

    And barrels are as round and straight as i can measure... apart from a small step at top where rings used to stop. Bottom step bareley noticeable.. guess because oil rings are not so harsh..
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  17. Just a thought, are you sure the rings are the right way up? I found 'top' marked on mine is tiny letters, so far from clear.

    Are the small ends a nice fit?

    Are all your Pistons pointing in the right direction?
     

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