Life at the end of the road

November 9, 2018

Back under the ‘bug’ :-)

Filed under: daily doings, pigs, Trucks and plant — Tags: , , — lifeattheendoftheroad @ 6:36 am

Five thirty and all is well, I tried to stay in bed longer but it was pointless, I was wide awake half an hour ago and in the end gave up, far too much to do to be stuck in bed. Not that I’ll actually be doing it just yet, gotta go over to Skye today with a mate to look at a hydro turbine. Still, it gives me time to catch up on here and ‘get all my 5h1t together’ Smile 

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Well, as you can see, we’re home at last, caught the 16:15 ferry yesterday after a quiet enough run up from Girvan, in bed for 20:00 then awoke to the ‘peach of a day’ that was Thursday 8th of November.

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Fed the animals and then it was straight out to the shed and ‘into the bug’ Smile A big heavy parcel from Megabug https://www.megabug.co.uk/ air cooled VW specialists was sat waiting for me at Sconser on Wednesday night and I was desperate to get stuck back into the Raasay Distillery camper. Firstly cos it was blocking me shed door, secondly cos I didn’t want to forget how to put it back together and thirdly cos I’d more important projects of my own to be getting on with Smile

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It was getting new barrels, pistons, heads and clutch so the first thing to be done was fit all the new studs to the heads then remove the old pistons. This I made easier by warming them up first with a blow torch. The new ones would be OK as they’d been sat in the house at 20 degrees all night and if they were a little tight on the gudgeon pin I’d bung them in the oven for ten minutes.

It was whilst removing the pistons that I encountered the first minor hiccup,

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a loose little end bush. Luckily the bush was still very much serviceable and the wear was in the conrod itself, so using the old gudgeon pin as an anvil I centre popped it all the way round and pressed it back into the rod with a G clamp. A good dose of Loctite 638 would ensure it stayed put and I’d previously marked the bush to ensure the oil galleries lined up.

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Although the pistons are actually already installed in the barrels when they arrive I removed them anyway as there was no guarantee that they had been lubricated or that the piston rings had been staggered correctly.

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This was a bit of a PITA as my piston ring clamp hasn’t been used in twenty years and needed much cleaning and fettling to get it to work. I had ordered another but it hadn’t arrived yet and when it does it’ll probably sit for another twenty years before it gets used Smile I guess VW air cooled pistons are unusual in the car world in that you fit them into the barrel barrel first then slide the whole assembly over the head studs prior to pushing the gudgeon pin through the piston. Normally you would fit the piston to the con rod then push it through the liner/cylinder block whole. There is an arrow on the piston that should point to the flywheel. I had to Google that cos half the old pistons were in the wrong way round with two arrows pointing to the flywheel and two to the crankshaft pully. The gudgeon pin on most internal combustion engine is not quite in the centre of the piston being offset ever so slightly away from the ‘thrust’ side of the bore.

Piston thrusts

During the power strokes, combustion pressures force the piston downwards. However, the piston does not bear evenly against the walls of the cylinder, but is thrust against the sides of the cylinder. This is caused by the angularity of the connecting rod (Figure 6.11).
The combustion pressures force the piston downwards, and the connecting rod offers resistance, but it does this at an angle. The result is a side thrust of the piston against the cylinder wall, as shown.
The piston also has a side thrust during the compression stroke, but this is on the opposite side of the cylinder. Also, this is a lesser thrust because the downward force from compression is much less than the downward force of combustion.
The thrusts are sometimes referred to as the major and minor thrusts. Because the thrust during the power stroke (major thrust) is most important, this side of the engine is often referred to as the thrust side of the engine. It is necessary to know about the thrust side of an engine because the pistons in most engines have to be installed in a particular way. Pistons are often provided with a mark to show how they should be fitted in relation to the front of the engine.

 Image result for thrust side of pistonhttp://pautomotivemechanics.blogspot.com/2011/06/piston-designs.html

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Once the barrels were on it was the turn of the heads, which on this are torqued down to a mere 18lb/ft !!! which really is not very much at all. Still, that’s what it says in the book so I guess it’s really important to make sure the threads are clean and the washers well oiled. With the heads on I set the valve clearances and much to my joy there was a huge gap in them after torqueing down the heads.

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This had been a bit of a concern for me and I’m still at a loss as to how it came about, though I suspect the old barrels must have been too short, though that does not explain how the vehicle had actually run for so long with no valve clearance. If you look at the image on the left you can see that the rocker screw is actually within the rocker arm, the image on the far right was taken after I’d set the valve clearance and you can see the rocker screw is now where it should be.

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As seems to be the case with these, it takes far longer to fit all the tin-ware and ancillaries than everything else and by 21:00 I’d had enough so ‘called it a day’.

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9 Comments »

  1. A busy engineer is a happy engineer Paul and that Bug is certainly keeping you busy 🙂

    Comment by Tigger — November 9, 2018 @ 7:58 am

    • Fingers crossed, that’ll be the ‘Bug’ running on Saturday Tigger.

      Comment by lifeattheendoftheroad — November 9, 2018 @ 10:30 pm

  2. How in the hell was that engine running? It must have sounded like a bucket of broken bolts (semi standard sound I guess) and had about 15hp!

    Comment by Matt — November 9, 2018 @ 9:37 am

    • I just cannae understand how it was running for so long and obviously well enough for a while, apparently it’s been to France!!!! Should just fly down Calum’s road when it’s finished 🙂

      Comment by lifeattheendoftheroad — November 9, 2018 @ 10:29 pm

      • I think the owners only conclusion on it’s return is that you’ve fitted a hidden Nitrous Oxide supply!

        Comment by Matt — November 9, 2018 @ 11:45 pm

  3. Followed this blog for a while now, with awe! How do you know how to do all this stuff, Paul?!

    Comment by Giles — November 9, 2018 @ 10:33 am

    • Looking back through my old diaries Giles and I’ve slowed down a lot 🙂

      Comment by lifeattheendoftheroad — November 9, 2018 @ 10:26 pm

  4. Sounds like your having fun Paul !

    Comment by v8mbo — November 9, 2018 @ 11:09 am

    • Great fun Robin 🙂

      Comment by lifeattheendoftheroad — November 9, 2018 @ 10:26 pm


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