Date:         Sat, 15 Jun 1996 15:12:58 -0600
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Dieter Dworkin Muller <dworkin@village.org>
Subject:      Re: The Adventure of the Thrown Rod 


Last weekend, I wrote:
:  The Gerbil ('66 w/ '71 engine) has had a ticking noise, a lot like a
:  really misadjusted valve, but nothing you do to the valves has any
:  effect on it.  One mechanic suggested that it was a bad rod.  [...]
:  
:  Well, it's been about five years now, and it finally went.  Instead of
:  a medium-volume ticking noise, it now alternates between a really loud
:  tick/clack and a really loud rattle (with engine speed held constant).
:  [...]
:  The noise seems to come from slightly right of center (FIF).  When
:  turning the engine over manually, there's quite a bit of resistance on
:  the compression stroke of number one, and not a whole lot on any of the
:  others.  Number two seems to have the least resistance of any of them.
:  These together make me suspect that number two is the one with the bad

Pulled the engine, and disassembled it to the point of removing the
cylinders.  In the process, we noted that the #2 and #3 plugs looked
like they'd been running hot (reddish-brown), #4 looked just about
perfect (gray), and #1 was black.  OK, I knew it was on the right
side, it's easy enough to believe it's #1 instead of #2.

Pulled the heads, everything looks fine (a fair amount of carbon on #1
and #3, but that's unrelated to the noises I've been hearing).  Pull
the cylinders.  All the pistons look ok so far.  Turn the engine over
a bit, and...where's #1?  There *is* no number one.  Well, there's the
flat part, and the pin that connects it to the connecting rod, but
there's nothing else.  No sides, no skirt.  What's left is flopping
around pretty loose on the end of the connecting rod.  I think I've
figured out what was making that noise now.

Aside to the person who has a similar valve-like ticking sound:  Pull
your engine *soon* and check the wrist pins.

After admiring the fact that the thing ran so long and so well without
much of a piston in there, we noticed something else that was even
more disturbing.  The connecting rod has major side-to-side play (the
loose end goes through an arc several millimeters long).  A little
experimentation shows that all of them have play, but in varying
amounts.

So at this point, I know I need to replace:

- oil cooler
- connecting rods
- crankshaft
- wrist pins
- rocker arms (unless replacement adjusters are available)
- pistons (might as well, since everything else farther in is toast)

Clean and Inspect items:

- oil pump
- case `bearings'
- cylinders

The outstanding questions are:

- how do I verify that the case itself is ok to use?
- would it be worth getting dual-intake-port heads, since everything
  else is getting swapped?  it currently has single-port heads.
- has anyone had good/bad experiences with the above parts acquired
  from Rocky Mountain Motor Works or Bus Boys?  RMMW has the advantage
  that they're close by, so I can go down to yell at them if I get
  annoyed enough; I'd rather know that I'll be getting the right thing
  the first time (unlike the muffler fiasco).
- should I think of this as a rebuild, or creating a new engine from
  scratch?
- just counting parts, would it be cheaper to resurrect this engine,
  or to buy a long block which I then rip apart, balance, and put back
  together?
- if the long block approach is the right one, where's the right place
  to get it from?  I already know GEX is probably a bad choice.

Well, I'm off to re-read the sermons....

	Dworkin