Date: Sun, 5 Sep 2010 12:30:30 -0700
Reply-To: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Turbovans <scottdaniel@TURBOVANS.COM>
Subject: Re: Clutch alignment tool? and Lapping compound ?
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wanted to comment on this -
"I
recall someone saying "If you can avoid 'unsealing a motor' you should. It
is difficult to get a good headgasket seal again"...They seem to have been
right on..cause mine did eventually leak."
there is one vanagon engine kit vendor who is adamant that the factory
sealing of a head and head gasket can never be duplicated out in the car
repair world. ..............All about computer controlled robots and hyper
accurate bolt torquing methods or whatever ...and that's probably mostly
true. He told a story about talking someone with a blown head on a late
model VW car into gettting a whole new engine, rather than just repairing
the head area.
All I can say is, ...
there must be about a thousand or more cylinder head jobs done in car repair
shops and machine shops *per day* in North American ..or whatever, some huge
number.
And if done with reasonable care and attettion to detail, the vast majority
of cylinder and head gasket jobs work out just fine long term.
workmanship is the most critical factor ..
'Sometimes' you can just put on a new head gasket ...but for a repair that
you expect to last a long long time, it's better to have a good machine shop
at least take a look at it.
things to consider .
first area .........leaking or burnt valves, worn valve guides, tired vavle
seals, if equipped.
2nd area ...sometimes you might want it pressure tested for leaks or cracks
...
there's specific tests to reveal cracks.
and there's surfacing ...and it's not an always 'do for sure ' ...it
depends..
depends on if the heads been resurfaced before ....
depends on the machine shop ...I've had heads that came back resurfaced with
grooves in them ..and the mahcine shop said that's just how their cutter is
on their resurfacing machine and they can't control it ...don't know if
that's true ...but not all heads come out really nicely after resurfacing
ever last time.
I'd say if it doesn't really need it, not doing it can be a fine choice.
there are a few engine designs that are just inherantly poor about head
gaskets.....
usually though, it's all abou workmanship, good machine shop work, super
attention to detail preparing it going on the block, and when installing it,
and torquing it down right etc.
you have a left over ABA head I believe done. hmmmm., where could I use
that ?
Scott
turbovans
----- Original Message -----
From: "Don Hanson" <dhanson928@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Saturday, September 04, 2010 4:16 PM
Subject: Clutch alignment tool? and Lapping compound ?
> I am in the process of swapping parts around in my 84 5sp manual
> transmission inline gas VW powered vanagon. I took out my 1.8 liter 92
> Jetta motor to swap in a 2.0 liter Jetta bottom end. I'll reinstall my
> 1.8
> liter head onto the new 2.0 liter block and also re-use my 1.8 liter
> 'everything else' almost on the ABA block. The ABA block is said to make
> more power.
>
> So I haven't swapped a clutch recently. I know I have to align the disc
> so it will remate with the output shaft of the trans. Most people seem to
> use a second old tranny shaft? Or some special tool? Is there a way to
> "McGuiver" something that would work without trying to source a spare
> shaft
> or mail order a clutch alignment tool? I did a quick Google and I see the
> tool for pretty inexpensive, but I really want to finish up this swap in a
> day or two and get my van going again. Could I carve or shape something
> from wood or PVC pipe or some-such, maybe duplicate the dimensions of my
> existing output shaft..since all the same parts need to remate anyhow? I
> am
> working alone, so I want my reinstallation of the motor to be as smooth as
> possible.
>
> Second question....I've seen valves lapped into heads using an abrasive
> compound on the valve seat and simply spinning the valve with some kind of
> compound between the valve and the seat. I want to surface my 1.8liter
> head
> myself, in that same manner. In order to clean off all the old gasket and
> get a good seal without taking it to a machine shop and trusting that job
> to
> someone I don't know, I want to use some lapping compound and a flat
> surface, like thick plate glass, and simply 'plane' the surface of the
> head
> by hand until it is shiny and flat. Has anyone done this? It looks like I
> can do it without removing the cam or the valves..just take off the
> manifolds and I have the bottom of the head clear. I want to put it
> face-down on the flat surface with some compound and simply 'sand down'
> the
> mating surface till it is smooth, clean and flat.
>
> I see that compound comes in a couple of "grades", like sandpaper. What
> grade do I need to go down to in order to get a good headgasket seal? My
> "new" block was not leaking when I took that head off. The old 1.8 liter
> one was leaking, but the head is ok, not cracked or badly warped. The
> last
> time I removed and replaced that head, I did not surface anything..and
> after
> 40k miles, the headgasket did blow out between two of the cylinders...I
> recall someone saying "If you can avoid 'unsealing a motor' you should. It
> is difficult to get a good headgasket seal again"...They seem to have been
> right on..cause mine did eventually leak...Probably due to me cutting
> corners with the re-assembly...
>
> Anyone know these answers or care to advise? Thanks
>
> Don Hanson
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