Date:         Sun, 14 May 1995 23:27:02 -0700 (PDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         David Schwarze <schwarze@superc.nosc.mil>
Subject:      Re: Add-on Oil Coolers

ATVenture@aol.com writes:
> 
> Did you use a new case?   A pounded case will transfer 20% of engine output
> into heating the engine.
> A 'line bore' will not make a pounded case good.

Ack!
	I should have pointed out that this is a type IV case, which is 
aluminum, not magnesium, and does not fatigue.  The bearings fit tightly
in their bores, just like they are supposed to.  I wouldn't have assembled
the engine otherwise.

> Most line bore tools are the bar type and just make begger holes in the case.
>  If the case was so whooped on to start with you have an incorect starting
> point for the machine work.  If the axis of rotation of the crankshaft is not
> in line and angled up correctly to the piston cylinders then that engine will
> never have the output and will always overheat.

I had my machine shop check the bore and they said it didn't need an align
bore.  I trust them, but who knows?  I suppose it's possible they were
wrong...

> That melling while a fine peice of machine work is no good.  The iron
> casting's rate of thermal expansion does not match the Mag-Al alloy of the
> case, so when your engine is warm oil leaks back into the sump from the high
> pressure side.   

I wonder if this is a problem with aluminum cases as well as magnesium?

> 		  It could also suck bubbles of air in on the intake side.
> also the pressure can go way too high with a melling, too much is too much.
>  You could have so much pressure that the stock relief valve will bypass the
> cooler even with a hot engine.

Good point.  But the only reason I went to the melling was because of low
oil pressure before the rebuild (yeah, I was mighty suprised that the
rebuild didn't fix the low oil pressure.  Turns out the pressure dropped
because the motor was overheating!)

> The stock pumps work fine, if you must get one from berg, they are stock but
> the alluminum has been treated (anodized) to make the surface harder/wear
> better. 

I'll do that next time around.  Thanks for all of the feedback, everyone!  :)

-David

============================================================================
David Schwarze                     '73 VW Safare Custom Camper  (Da Boat)
SAIC Comsystems, San Diego Calif.  '73 Capri GT 2800            (Da Beast)
e-mail:  schwarze@nosc.mil         '87 Mustang Lx 5.0           (Da Sleeper)
http://papaya.nosc.mil/~schwarze   '93 Weber WG-50              (Da Piano)
============================================================================