Conference terri::cars_uk

re: gasket sealants

	. don't bother. The gasket should be enough on its own. This
	is from experience of rebuilding many bike engines, and at least
	five car engine. So far, no leaks. Just get the surfaces clean
	and flat, grease paper gaskets lightly to help them stay in place
	and that's about it.

    Mark,
    
    Valves. the quickest (ergo often cheapest) option is to get the valves
    "faced" at an engineering shop. They will still need final finishing
    with fine paste. It you fancy doing it all yourself, and this depends
    on the state of them, then you should follow the coarse/fine method.
    Either way, I would strongly recommend doing it, as doing them later,
    ie. before the breakdown of everything else, will be time consuming and
    expensive. In other words, whilst it's in bits, go the extra yard.
    
    Gaskets. Well, I've never used the  stuff on heads, mainly because
    that's the way I was taught. I believe they should only be used on
    surfaces that are either coarsely machined, or rough. Heads fall into
    neither category, and if the latter, need machining.
    
    Laurie.

     Is it possible to change the crankshaft and connecting rod bearings from 
     underneath an engine, without removing it from the car or removing the 
     cylinder head.  This is particularly time consuming with fuel-injection 
     inlet manifolds due to all the connecting pipes.
     
     Has anyone had the head off a VW Watercooled, Fuel-injection based 
     engine?  I have attempted to understand the Haynes manual, but there is 
     too much cross-referencing to make it easily understandable.
     
     I have never attempted such work, but would enjoy doing so to save paying 
     someone �25*4 hours (?) to do a technically straightforward job.
     
     

    Well, in my experience, yes, it's perfectly possible. I've never done a
    VW engine, so I can't speak for that, but I'd bet it's possible.
    
    The con-rods are no problem, since if you remove the plugs, you can move
    them up far enough to get the new bearings in. Take GREAT care that
    they are properly seated before you tighten anything up.
    
    As for the crank, push the old (top side) bearings out with the new,
    taking note of which side the notch is (if there is one). Do one at a
    time or you'll upset the crank!
    
    Don't torque or tighten anything up until *all* the bearings are
    correctly in place. Use lots of oil, of graphite lube stuff.
    
    Laurie.

I've changed the con-rod bearings this way ... a real pig of a job. Oil
dripping in your face, up your arms etc etc

Getting the crank out could be a problem ... you will need to remove the
flywheel, clutch and if it is an OHC, the timing belt drive.

What is it you want to do exactly ??? If it is replace the bearing shells,
this might be possible. If you want to regrind the crank, then I'd be
inclined to take the engine out.

    
    Crankshaft bearings.... 

    I'd have thought that changing the big end bearings would always
    be possible. But the the main crankshaft bearings might be a lot
    more troublesome or even impossible. Depends on the engine. With
    no knowledege of the VW block... no comment.
    
    Changing the little ends is, as someone implied just bloody messy.
    
    Richard.
    

Well, I've changed the connecting rods that way in a spitfire and a 
Plymouth Duster. It was a real pain to get the oil pan off on the 
Plymouth because the steering arms run very close under one part of 
it.

I've taken the head off a carbureted VW but not a fuel injected one. 
It was actually a pretty simple job. On our injected VW however, it
did not look like it would be an easy chore. 

Did you have an oil starvation problem? If so, you'll also need at 
least new cam bearings. They are far from the oil pump and the cam 
turns faster then the crank. If so, it's usually easiest to buy a
rebuilt head. 

    Re: 1612.8
    
    
>>> least new cam bearings. They are far from the oil pump and the cam 
>>> turns faster then the crank. If so, it's usually easiest to buy a
    
     What sort of strange engine is this?
    
    - John.

    	I'm not familiar with "modern" VW engines but when I used to do a
    bit of work on VW Beetle engines, I seem to remember the block split in
    half <- this way -> rather than /\
    				    \/ this way so you couldn't remove the
    crank without taking the whole thing to bits. It was fun though, taking
    all the barrels off! Nice engine to work on except you had to take it
    out to do almost anything unless you were an ambidextrous,
    triple-joined contortionist!
    
    Colin

    ...more on gasket gunge...
    
    This stuff is useful for low-pressure applications, when castings have
    distorted & you don't want to regrind the mating surfaces. Its handy
    when you want to 'glue' a gasket in place when you run out of hands.
    
    Why do I ALWAYS stand on the Hermetite tube ? (Doesn't it go a long
    way :^] ).
    
    	Tony.

    
    The section in the Haynes manual on how to rebuild the Essex says that
    gaket gunge is 'a sensible measure, if not essential' when fitting the
    inlet manifold, due the large area and number of water lines running
    through the manifold. It seems a sensible suggestion, so I'll get some.
    As Tony says, it's also handy for sticking gaskets in place, but often
    a smear of grease will achieve the same thing.
    
    Mark

    Makes me wonder just who funds Haynes manuals :-)
    
     A bit like a lot of Classic car mags mentioning the use of
     WAXOIL ...
    
    But seriously, if you buy the correct gasket, it will usually
    be of the right material for the job, even to the extent of
    having a sticky or waxy surface when necessary.
    

    I'm currently rebuilding a Ford 2.8 V6 engine. A problem I have run up
    against is removing the cam followers. According to the Haynes manual it
    should be possible to poke a piece of wire through a hole adjacent to
    each follower and lift them up out of the engine. I have found that
    none of the followers will come up past the top of their bores. I am
    assuming that a slight lip has been worn in the bores preventing them
    from coming out. 
    	Is there a way round this? It looks like most, possibly all of them
    could be driven out by a long punch from underneath in the crankcase. I
    am not too worried about damaging the faces of the followers as they are
    to be replaced when the new cam goes in. Is this feasible? Is this a
    common problem? Any other way of getting them out?
    
    		Jeremy

Some comments on replacing piston rings would be useful.  Assume that have 
already gone through the oil in face big end-change and head removal 
procedure before.

Any "while you're in there" tips?

Thanks,
Rob.

Lightly hone the cylinder walls to remove any ridges, especially near the top 
of the block.  You may want to check the diameter of the cylinders to see if 
you need oversized rings (or pistons.)

Dave

Thanks Dave,

When I has last in there, we did check the bore for ovality with a bore 
micrometer, wear in the bores was very negligable.  I'm annoyed that I 
didn't take readings at the same time.  Could not see any ridges, scratches 
or any signs of damage to the bores.

Would it be ok to assume that the cylinder wouldn't wear all around, and 
since it is still round and not slightly oval; there isn't the need for 
oversized components?

My father mentioned they used to use ring shimming inside the ring groves 
to make the new rings nice and snug.  Is this still the done thing for a 
1982-1992 engine?  No mention of such arcane practice in the Haynes 
reference.

The Haynes manual also mentions some VW engines have springs attached to 
the third oil-scraper ring to reduce excessing oil consumption.  Have you 
seen such things?

I take it with new rings I will have to run the engine in.  What regime 
would you stick to and for how long?  The big-end bearings are recent so 
won't need replacing or running in after re-assembly.

Apparently there are a few types of ring compressor for getting things back 
in the bores, what preferences do you have?

Depending on the weather, I may get a valve compressor and remove all the 
valves/camshaft and take the head to have new valve guides pressed in.  
There was a small amount of play with the valves in them, not enough to 
really worry about at the time.  But this time I want to do EVERYTHING 
worth doing while the head's off again!   I have a flexible couple of days 
free and a spare car available while mine's worked on.

Please keep those suggestions comming in.

Rob.

>Would it be ok to assume that the cylinder wouldn't wear all around, and 
>since it is still round and not slightly oval; there isn't the need for 
>oversized components?

If everything looked okay (roundness and size) last time, it'll probably be 
okay this time too.  You'll want to closely look at the rings when you take 
them out to see if you can find any failure points.

>My father mentioned they used to use ring shimming inside the ring groves 
>to make the new rings nice and snug.  Is this still the done thing for a 
>1982-1992 engine?  No mention of such arcane practice in the Haynes 
>reference.

Sounds like something I'd use on my 1920's Studebakers - max revs about 2000. 
I wouldn't suggest that for a modern engine.

>The Haynes manual also mentions some VW engines have springs attached to 
>the third oil-scraper ring to reduce excessing oil consumption.  Have you 
>seen such things?

The set of rings I have for my '79 diesel Golf have springs in one of the
sets.  That might be what they are talking about.

>I take it with new rings I will have to run the engine in.  What regime 
>would you stick to and for how long?  The big-end bearings are recent so 
>won't need replacing or running in after re-assembly.

Let's see, about 6000rpm for the first 100 miles, then slowly bring it up to 
redline...! :-)

Don't know actually, the last engine we totally rebuilt was for racing so
it didn't really matter.

>Apparently there are a few types of ring compressor for getting things back 
>in the bores, what preferences do you have?

I've used the ones that look like a tin can that you compress around the 
whole piston.

Have fun!

Dave

    
    Seen something in car & car conversions where you have to "BED" the
    rings in by starting the engine and taking it up 4000 rev for a minute
    and then back down to 1500 for another minute and back up to something
    else. I will look it up but i am not back in on shift until Thu night.
                    
    colin 

Oh well,
It's now had 100 miles of VERY gentle running in.  First 50 I didn't go 
over 2500 revs, nor even put my toe down, mostly travelling at 30 mph!

I'm now allowing the big 3500 revs and a little throttle, may even hit 60 
mph soon.

Cyl 1 top compression ring was siezed in the groove with carbon.  Biggest 
wear was 2 thou at the top of number 2 cyl, others were about 1 thou top, 
middle and cottom of the bore, sideways wear from crankshaft rotation was 
un-measurably low.

It was one of the most unpleasant experiences in my life; under an oily 
engine sump on a wet carpet in the rain, with my jeans falling in a puddle 
under the car.  Yep my father's drive and it was raining, but I wasn't 
going to stop for much.

Thing feels nice, smooth and tight now.  Can't wait to be able to push it a 
little.

Thanks,
Rob.

>It was one of the most unpleasant experiences in my life; under an oily 
>engine sump on a wet carpet in the rain, with my jeans falling in a puddle 
>under the car.  Yep my father's drive and it was raining, but I wasn't 
>going to stop for much.

You've now completed the first training course in the rally mechanics 
course.

Next lesson, freezing rain/snow and warm exhaust headers....

Dave

>>>It was one of the most unpleasant experiences in my life; under an oily 
>>>engine sump on a wet carpet in the rain, with my jeans falling in a puddle 
>>>under the car.  Yep my father's drive and it was raining, but I wasn't 
>>>going to stop for much.

>>>Thing feels nice, smooth and tight now.  Can't wait to be able to push it a 
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>>little.         

>>>Thanks,

	Are we speaking of the jeans or the engine?

				Malcolm. 8^)

Well, I finally got around to tearing into the diesel Rabbit we bought a few
years ago.  When I first bought it, it ran but was very low on power.
Eventually it got to the point it would not start, just crank.  I had the
injection timing checked, and it was set properly.  The diagnosis I received
from my local VW repair shop (not dealer) was bad rings, so I bought a new set
of rings and con rod bearings.

Over the last two weekends I pulled the oil pan and head off and yanked the
pistons and rods out.  The lower compression ring on #4 was stuck in the
groove and the lower compression ring on #1 was broken.  These appear to be
the cause of the problem.  I cleaned everything up and found that the face of
the piston and head for #4 had pits all over them.  I ground down the few high
points, but it looks like something got sucked in or a piece of ring broke off
and got banged around in there.  I'll check the glow plug to see if the tip
got broken off because the valves look fine.

The bottom end is back together now and the con rod bearings are on the tight
side (.0011 to .0033 is the range and they are between .0012 and .0015)  I'll
have the head gasket set this week so I can put the rest together.  I also
replaced the timing belt while I was in there.

Dave