Date:         Tue, 12 Aug 2008 11:46:54 -0700
Reply-To:     David Kao <dtkao0205@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Kao <dtkao0205@YAHOO.COM>
Subject:      Re: Engine Replacement Options
In-Reply-To:  <BAY125-F377C28A0C50DD9E44C8150A0700@phx.gbl>
Content-Type: text/plain; charset=iso-8859-1

This is indeed an option. But the rule of you get what you pay does
apply in this case I believe. A worn engine will never be the same
with rebuilt parts, especially for critical parts like cylinder heads.
I do wonder how well in general rebuilt heads perform. I am kind of
reluctant to have my used AMC heads rebuilt. Either just use them as
they are or forget about them and buy new. I always have fear getting
near to a machine shop.

David


--- Dennis Haynes <d23haynes57@HOTMAIL.COM> wrote:

> Valve guides are replaceable. A beast of a job but doable.
> The real problem of worn valve guides is worn intakes can cuase oil to get
> sucked in and worn exhausts will allow exhaust into the crankcase. Fuel
> injected cars tend to wear the intakes. The intake vlaves can get a stem
> seal (washer) to keep the oil away from the guide. Same part as used on the
> air cooled.
>
> Dennis
>
>
> >From: David Kao <dtkao0205@YAHOO.COM>
> >Reply-To: David Kao <dtkao0205@YAHOO.COM>
> >To: vanagon@GERRY.VANAGON.COM
> >Subject: Re: Engine Replacement Options
> >Date: Mon, 11 Aug 2008 22:30:33 -0700
> >
> >Yes, you are right that valve guides must be checked to be within
> >the wear limit to be reusable. Bentley says to insert a new valve
> >(not the old valve) into the valve guide. The end of the valve stem
> >must be flush with the end of the valve guide then wiggle the valve.
> >The wear limit in this case is 1.2 mm movement. I did not measure
> >the wear on my OEM heads before I installed them on my 83.5. But
> >I remember that I could barely wiggle it at all. I felt there was no
> >possibility they had reached 1.2 mm. So I skipped the check with a
> >dial measuring tool. The Valve guide wear on my AMC spare heads
> >are more significant. But they are still much smaller than 1.2 mm.
> >The heads are still fairly usable I believe.
> >
> >I am confident that my 83.5 Engine has a solid short block. But
> >of course only time will tell. Currently it idles very nicely. It
> >accelerates the way it is supposed to. The cooling system appears to be
> >completely normal during my two recent trips to Yosemite. I am sure
> >there are lots of miles to go still for this Westy. So I will not face
> >a decision between rebuild or conversion any time soon.
> >
> >I hope to reach 200k miles before I will need another rebuild.
> >
> >David
> >
> >
> >
> >
> >
> >
> >--- Mike <mbucchino@CHARTER.NET> wrote:
> >
> > >   You need to measure the valve stem to guide 'wiggle' against the book
> > > standard, to know if it's at or beyond the wear limit.  The valve has to
> >be
> > > a certain distance off the seat; per the book. I don't remember these
> > > measurements of the top of my head, but you can't judge without
> >measuring.
> > > And you're right, they need to be dry for an accurate measurement, the
> > > lubricant will take up some of the play.
> > >   A engine with a new, strong top end has been known to be last straw
> >for a
> > > marginal bottom end.  You may learn this old lesson first hand
> >soon.........
> > >
> > > ----- Original Message -----
> > > From: "David Kao" <dtkao0205@YAHOO.COM>
> > > To: <vanagon@GERRY.VANAGON.COM>
> > > Sent: Monday, August 11, 2008 9:03 PM
> > > Subject: Re: Engine Replacement Options
> > >
> > >
> > > >I absolutely agree with you that I took a risk in not doing anything,
> > > > not even checking, the short block. The reason was the 83.5 Westy had
> > > > only 110K original miles. Most 1.9 WBX engine wore out from the heads
> > > > first. Very few had short block problems. I bought the Westy when it
> > > > was less than 60k mile young. I knew the history of it pretty well.
> > > > I don't think I took too much a risk in assuming that the short block
> > > > was OK.
> > > >
> > > > I have a pair of used AMC heads. It passed my alcohol leak test too.
> > > > But when I checked the valve guides they were not as tight as that on
> > > > my 83.5 heads. My 83.5 heads were VW OEM and were put on by a VW
> >dealer
> > > > only about 20k miles ago. I lapped the valves and checked the guides
> > > > before doing the leak test. The guides were amazingly tight still.
> > > > So I knew I had an excellent pair of heads to begin with. That's why
> > > > I only replaced the cylinder/piston liners. The valve guides of my
> > > > used AMC heads are definitely not as tight. If there is oil in the
> >guide
> > > > you won't feel a play when wiggle it back and forth. But if it is free
> > > > of oil (clean and dry) then I can feel a play when wiggling it.
> > > >
> > > > I think the heads are still quite usable. But then it may be a
> >question
> > > > how long it will last and how well it will work. Nothing beats a new
> >pair
> > > > of OEM heads at $1000. If the budget permits that's the way to go.
> > > >
> > > > David
> > > >
> > > >
> > > > --- Mike <mbucchino@charter.net> wrote:
> > > >
> > > >>   The seating of all the valves is not the only thing that must be
> > > >> checked,
> > > >> when choosing to rebuild a head.  You haven't said that you've
> >removed
> > > >> the
> > > >> springs to check the valve-stem-to-guide clearances/ wear and
> >cleaning of
> > > >> carbon deposits.
> > > >>
> > > >> > I used alcohol for the leak test. I poured it to the opposite side
> >of
> > > >> > the
> > > >> > valves and check for sign of leak on the valve stems. Mine had no
> >leak
> > > >> > for
> > > >> > 3 minutes and possibly longer than that.
> > > >>
> > > >>
> > > >>   Removing the rods to replace the rod bearings and take the
> >opportunity
> > > >> to
> > > >> inspect and measure the crank's rod journals.  This may uncover
> >damage
> > > >> that'll point to a total overhaul; 'not checking' at this point in
> >the
> > > >> disassembly is a mistake.  One that may bite you in the ass sooner
> >than
> > > >> later.  It's not a huge step to go all the way at this point.
> > > >>
> > > >> > Rebuilding a short block is something I have not tried.
> > > >> >
> > > >> > David
> > > >>
> > > >>
> > >
>