<VV> engine noise

[Roger Gault]

Lonny,
Any thing is possible, but I doubt seriously that you bent a rod if the only
piston damage was a small crescent on the top.

Did the valve seat come apart, or just out of the head.  If it broke, you
might have a piece mushed into the head or piston in the squish area.  It
could be in any cylinder on that side.

Or, if one of the studs turned when you put the head back on, you might have
screwed the stud in far enough to have it hit the crank.  There's not much
clearance there.  Only half the studs can cause this problem.  If you sit on
the ground looking at the side of the engine, it's the studs on the right
side of each cylinder.  The ones on the left go into the bearing webs and
are not close to the rod cap when it comes around.

I'd pull the plugs and rotate the engine by hand to see if I could feel the
bind.  Maybe you can tell where it is from where the bind is.  If it's right
at TDC for one of the cylinders, you probably have something in the
cylinder.

If that doesn't bear fruit, you might try running the engine and reaching in
and touching the tops of the studs to see if you can feel a shock when the
rod cap hits.  Obviously you have to be a contortionist to do this, and will
have to have the valve cover off to touch the lower ones.

Otherwise, one of the smarter guys here will have to help.

Good luck,
  Roger

----- Original Message ----- 
From: "Lonny Clark" <lclarkpdx at gmail.com>
To: "Mike Kost" <vairmike at sbcglobal.net>
Cc: <VirtualVairs at corvair.org>
Sent: Monday, September 11, 2006 8:00 PM
Subject: Re: <VV> engine noise


> Piston had been hit, but it didn't look like it was hit very hard. It
looked
> like the soot had been cleaned off of a small crescent where the valve
> contacted it. How hard does it have to hit to bend the rod? If the rod is
> bent, can I expect low compression on that cylinder? If so, how low? Can I
> tell if this is the case without taking the engine completely apart?
>
> On 9/11/06, Mike Kost <vairmike at sbcglobal.net> wrote:
> >
> > Lonny Clark wrote:
> >
> > > Well, I need advice again. After the Portland convention I had a
problem
> > > with my newly rebuilt Spyder engine. After throwing the belt, I pulled
> > > into
> > > a parking lot and put the belt back on. When I restarted it, it was
> > > running
> > > really badly and made an awful noise (knock, or clang). I did a
> > > compression
> > > check, one cylinder had zero compression. I posted that information to
> > > the
> > > list, and received the advice that I had lost a valve seat. After much
> > > work
> > > and procrastination, I got the engine out (needed new input shaft seal
> > > anyway) , and pulled the head. Sure enough, ex. seat on #2 was popped
> > > out. I
> > > took the head in, had it welded up, and a new seat and valve
> > > installed. It
> > > cost twice the estimate, but that's a complaint, and not helpful here.
> > >
> > > I reinstalled the head, put the engine back in, sorted out what wires
> > > went
> > > where, and started the car. The good news is it runs great, fires on
all
> > > six, revs good. The bad news: There's still a really nasty knock or
> > > clang.
> > > It's rythmic, sounds like one sound per revolution. I can't tell where
> > > it's
> > > coming from, but sounds like it's internal. How do I find this one? Do
I
> > > need to rebuild the engine - again? It only has 40 miles on it.
> > >
> > > I'm starting to get upset at the amount of work this car has taken to
> > > get to
> > > this point, and I still can't drive it. (about the same feeling I got
> > > last
> > > year)
> >
> > You may have bent a rod when you lost the valve seat (BTDT). Did you
> > check piston for damage?
> >
> > Mike Kost
> > _______________________________________________
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>
> -- 
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