Date: Thu, 8 Aug 2002 21:15:37 -0600
Reply-To: Gary Shea <shea@GTSDESIGN.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Gary Shea <shea@GTSDESIGN.COM>
Subject: Re: Why this type IV engine caught fire,
spun the mains and ruined everything.
In-Reply-To: <20020808.211856.448.6.wilden1@juno.com>
Content-Type: TEXT/PLAIN; charset=US-ASCII
[2002-08-08 21:18 -0500] Stan Wilder (wilden1@juno.com) wrote:
> If you look at the bearing you'll see that the pin missed the bearing
> alignment hole.
> The pin applied undue pressure on the bearing that may have been a
> friction factor as well.
> The bearing became ever so lightly egg shaped as the case tightened, this
> condition may not have caused the crank to lock while the rods / etc were
> being installed but eventually it caused the engine to fail from oil
> starvation to almost all engine bearings.
> Every bearing shows signs of operating under extreme heat and are failed.
> I can visualize that the engine may have held 5/8 pounds of oil pressure
> and the idiot light might not have signaled the operator but as heat
> built up and the oil thinned it could have continued with enough pressure
> that the sender might not activate the oil indicator light.
> During installation the case may have originally dropped together
> properly but considering Murphy's law the bearing could have moved as the
> case was rotated, rolled over or handles in the bolting together process.
> As for the snap together, the case is a precision fit and when you drop
> the top (left side) onto the bottom side (right side) with the case in a
> holder, on an engine stand, sitting on wood blocks it just gravity drops
> into place with a snap sound. Any misalignment at this time and you'll
> know something is holding the two halves apart.
>
> Stan
Hi Stan!
Thanks for the detailed reply! I was confused because I forgot that
you'd given a pointer to a picture. Whoops!
Ok, I'm finally looking at the picture. So what we're seeing is the
back of the bearing shell where the registration pin bit into it? And
as a result of the bearing shell being misaligned, the oil hole for that
bearing is blocked. The reason for the lack of oil pressure I'm not so
clear on, I can't remember where the oil hole is with respect to the
registration pin, but if they're near each other I can imagine oil
coming out freely under the shell... is that what was happening?
I recall having a hell of a time getting the case to go together easily
on my '81. Kept knocking stuff out of alignment, etc. But it's easy to
tell when everything is right.
Regards,
Gary
| 
