<VV> Engine noise question - sorry, long

Hank Kaczmarek kaczmarek@charter.net
Sun, 20 Jun 2004 18:40:23 -0400


Folks
Has anyone found out what this guy's problem is with his engine yet???  I
would be interested in finding the answer to this one.

HANK
----- Original Message ----- 
From: <BobHelt@AOL.com>
To: <UltraMonzaWest@AOL.com>; <virtualvairs@skiblack.com>
Sent: Saturday, June 19, 2004 1:33 PM
Subject: Re: <VV> Engine noise question - sorry, long


> In a message dated 6/19/04 9:38:09 AM US Mountain Standard Time,
> UltraMonzaWest@aol.com writes:
>
> > If so....why didn't he hear it in the previous 50 miles of driving?
> >
> Well, as we all know, any speculation is simply a guess. And even that is
> based on the info provided and how that is interpreted.
>
> Todd reported the following........
>
> At
> idle, it sounded pretty normal, certainly like it is hitting on all
> cylinders.
> As I would flip the throttle, raising it above idle, it would make the
> knocking sound again, coming from the center of the engine, I believe.
The
> knocking would get louder the higher the revs, and disappear, or almost
> disappear at
> idle.
>
> So here we have a noise that seems to get louder as the RPMs increase. So
> maybe Todd couldn't hear the noise previously because of road noise at
speed.
> Remember he heard the noise AFTER he got to town. So maybe the noise was
with
> him
> all the time he was at speed and he just copuldn't hear it above all the
> other noise.
>
> Now it would seem logical that the inertia at high speed would throw the
rod
> end closer to the stud end, so if there was a little extra play in that
> bearing, the rod would move closer to the stud as the RPMs increased. Who
> knows?
> Maybe the burst of detonation mentioned caused just enough bearing wear
> (actually
> deformation) to increase the clearance just enough to have the rod hit the
> stud (assuming that the stud was inserted into the crankcase further than
> stock.
> So that, along with temperature expansion effects cause the hitting.
>
> Also looking at the situation as a whole, what are the probabilities?
Rings
> and piston? doubtful. Maybe the piston lost a piece, but why would that
occur?
> Head? doubtful. Lifter/adjustment? possible, but don't fit the description
of
> the problem. The engine seems to run just fine otherwise he reports. Junk
on
> top of the piston (so it hits the head)? Possible, but not included in the
> description. This could be a cause however. What's left? Possibly a stud
that
> turned when he removed the head, so that when the stud was reseated, it
was
> inserted too far into the crankcase. This is also a possibility and the
one I
> think
> caused the problem. But who knows? This is a guessing game for sure.
>
> Regards,
> Bob Helt
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