Re: A raft of engine rebuild Q's

[Cheapass Ron <rapieper@yahoo.com>]

Ben:

Before these questions can be satisfactorily answered,
we'd need to know  what condition the block is in and
any known running history (did it burn oil, etc.),
what you want this engine to be when you're done, and
what your budget it.

But what answers I can provide are below:

> 1.   What are the machine shop essentials for a
> rebuild?  Magnafluxing for 
> the head, block, and crank? (this is to check for
> cracks, right?)  

Yes, it's to check for cracks.  If you know this
engine ran well before teardown, I'd skip it.  I'd
have them check bore sizes with a dial bore gauge,
this tells you how oval your cylinders are, and
whether a rebore is required.  Also, inspect head bolt
holes.  I've had a few that were corroded and failed,
had to heli-coil them.

Hot 
> tanking to clean the oil and water passages? 

Opens pandora's box re: removal of freeze plugs and
galley plugs.  You can actually do a pretty good job
with hot water, dish soap, and a variety of bottle
brushes, after degreasing of course.

> Checking the deck height?  

Again, if it ran well before, you may be able to skip
this.

> Honing the cylinder walls?

Yep, I'd suggest this, see comment about checking bore
diameters above.

> 
> 2.  What is knife-edging of the crank?  What about
> micropolishing?

IMO neither are required unless you're absolutely
going all out.  You have to consider the balancing
issues raised when knife-edging, which is putting a
'sharp edge' on the crank counterweights so they don't
splash the oil...visualization: smack your hand flat
into water, lotsa resistance.  Smack your hand
sideways into water, karate chop style, less
resistance.  AFA HP gains, I believe this provides
little gain, it's more for an all-out engine.

> 3. Is an x-angle valve job necessary?  What should
> "x" be?  

Usually 3.  It's a performance grind.

Is hand lapping 
> an alternative to having the valves and seats
> machined?  

Whenever you grind or replace a valve, valve seat, or
guide, the valve should be lapped into the seat.

I gather that the 
> valve guides and seals are must replace items but
> what about the springs and 
> valves themselves?  Should the valve springs be
> tested and reused or 
> replaced with new ones?  Can valves that aren't
> burnt be reused safely?

I'm a cheapass, I'd re-use the old stuff if it's
within spec.  Performance wise, new springs are a very
good idea, of course with new keepers, etc.

> 
> 4.  Should all of the cam, crank, and rod bearings
> be replaced and not 
> reused?

Yes, no question about it.  There are no cam bearings
on a dub; the bearing surfaces are built right into
the head.  If one is bad, you may either be facing
some machine work or a new head.

> 5.  Is a thread chaser the same as a tap?  Normally
> will the machine shop 
> clean all the threads or is this something I'd do
> myself?  

I've always used a tap.  DIY, shop charges $50 -
$60/hr!

And if the 
> latter, how many different thread chasers do I need
> for an 8V block and 
> head?

sorry, dunno

> 
> 6. Are freeze plugs and galley plugs the same thing?
>  Should they be removed 
> prior to hot tanking for a more thorough cleaning?

No, they're different, freeze plugs are for coolant
passages and galley plugs are for oil galleys.  They
should be removed for an ultimate cleaning, but IMO
that's going pretty far.  I'd be more comfortable with
factory installed plugs as my confidence that they're
installed correctly is high (vs. that they might come
out if I FUBAR the installation)

> 
> 7.  Are VW blocks painted from the factory or is the
> dark color some type of 
> oxidation?

Black, I believe.  Good idea to paint with Rustoleum
Rusty metal primer (believe it or not, using that
stuff on the inside of the block is an old muscle car
trick, supposed to help the flow of oil back to the
pan) then maybe some nice red  or yellow hammer finish
would be cool...

HTH, 

Ron


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