Date: Sat, 23 Nov 2013 00:36:07 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: off with her heads
In-Reply-To: <CAFNeVpHoBab+a9RNhJYNDgDQA8M8H8W4UoQH98W5Ph1jF8i1Uw@mail.gmail.com>
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See below!
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Tom Carchrae
Sent: Friday, November 22, 2013 4:50 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: off with her heads
Hi All,
I got the bolts fixed and the heads vacuum tested by the machine shop (if
you are in Vancouver, Alec's
https://plus.google.com/103170149757334342065/about?hl=en - they were
helpful and seemed pretty fair). All good, and my 1984 NLA
thermostat/water-pump housing is saved from the snapped bolts... for now.
How important is it to hone a used cylinder. The internet seemed full of
opinion on it. I remember Dennis saying to carefully remove the carbon on
the top, but honing to help the "piston rings seat' (I am replacing the
rings) did not yield any clear answer on the great internet.
I really don't believe in honing the cylinders much. You need to measure
carefully. It is easy to remove a few thousandths quickly and you will end
up with an engine with piston slap noises. I am even seeing (hearing) this
with engine rebuilt with the new knock off cylinder kits.
I had also asked them if they could clean up/smooth the surface area under
the compression gasket (where the head mates with the cylinder) and they
said they were not sure how to do that properly, but they had called around
to some other shops to ask and suggested I take it there (which I totally
respect them for admitting that). I am considering doing this myself -
there is no major damage. The worst is a small scratch from the (first and
only) use of a screwdriver to remove the compression gasket - the rest of it
is just carbon crap.
Machining the tops of the barrels requires a lathe and someone who knows
what they are doing. The lathe and the chuck needs to accurate. I have
probably replaced more cylinder sets due to top damage or bad pistons than
cylinder wear or bore damage. You can try cleaning the tops using a very
flat surface and a fine grit emery. If you can see or feel the scratch I
wouldn't use the cylinder. Not only does the top of the cylinder have to e
near perfect, the two of them side by side have to be perfect together.
Hylomar is a good sealant to use on this gasket and the O-ring.
I am considering removing the engine to check the clutch, although I don't
have a floor jack and the engine is really high up from the ground (van is
up on blocks). I might try the winch method, or just leave it. Common
sense tells me I should check the clutch while I am in this deep (how deep
is the rabbit hole...). And I'm sure I'll my sanity will thank me when I
put the piston rings on (without removing the pistons).
If you're going to work on your van at some point a good floor jack is a
must. Get it over with and get one. Look for one with a large saddle.
Preferably a removable saddle so that tranny adapters and stuff can be
fitted.
Tom
