Date: Mon, 11 Aug 2008 22:30:33 -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: <108901c8fc1a$65b15990$0b00a8c0@mike2d93581d7f>
Content-Type: text/plain; charset=iso-8859-1
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
> >>
> >>
>
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