CorvAircraft>

[Mark Langford]

Scott Laughlin wrote:

> 1)  Order and receive new valves, springs, valve guides, retainers and 
> seals.
>
> 2)  Bring heads to competent speed shop along with items in #1.
>
> 3)  Pay for and retrieve a few days later.

That's a good point, especially the "competent speed shop" part.  It does 
sounds awfully easy, but the problem is that you have no idea if it was done 
right or not.  Mechanics know that people bring cars (or heads) to them 
because they have no idea how to repair it, and even if they did, they're 
not going to disassemble it to find out if it was done right.  So....there's 
an awful temptation to let things slide that really ought to be set right, 
stuff like cutting the seats out with one angle, because it's fast, but will 
not be self cleaning and will be less likely to seal once it has some hours 
on it.

I used to be a mechanic, and always tried to impress the customer with my 
work, whether he could see it or not.  But I've pulled apart a lot of 
engines where some hack had done some of the craziest stuff, and it lastest 
long enough for the car to get out of the shop, a few months or years to 
pass, and then it came apart prematurely.  I'm a firm believer in "if you 
want it done right, you have to do it yourself".  There's an example of 
exactly what I'm talking about at the bottom of the link that I posted 
earlier, but I'll post it below here because it illustrates my point.  The 
"reputable engine builder" mentioned is somebody that just about everybody 
on this list has heard of, so we're not talking local shadetree.  So here's 
the story:
--------
The question of quality reminds me of Jim Hill's engine. When I first met 
him he complained that it took forever for his "rings to seat" in his KR2. 
It seems his 2180 ran like a 3.5 cylinder for the first 50 hours, then 
smoothed out, but at 100 hours it became a 3 cylinder. He went thru this 3 
times, each time getting a "valve job" from a supposedly reputable engine 
builder, until I insisted he let me look at his heads. First thing I did was 
notice that one of his valve guides had a lot of slop and the seat was quite 
eroded, so I knocked out the guide, and went to the freezer and got a new 
valve to drive in it's place (yes, I keep a box of VW guides in my freezer 
at all times). When I started grinding the seat, the stone only gound one 
side, sort of crecent shaped like my example above! Hmmm.
It became obvious that the guide boss was not coaxial with the seat when the 
head was manufactured. I ground the crap of it until it sealed, but I 
couldn't help but wonder what mechanic bozo would do a "valve job" and not 
even bother to blue it and lap the valve, which would have graphically shown 
the total lack of seal between valve and seat.

What was happening was the valve wouldn't seal, but the side forces on the 
valve would eventually elongate the bore in the guide until it did seat, and 
it would start running better, usually after about 50 hours. But then that 
slop in the seat would allow it to wobble around and wear the valve face and 
seat excessively until it needed another valve job at 100 hours. Happened 
three times, just like clock work.

This was the first time I'd ever seen this phenomenon on a head straight 
from the factory, but somebody else had THREE opportunities to notice it 
before I did. This is just one of the many reasons nobody touches any of my 
cars but me (not even my wife's new Audi A4 Quattro, which is under warranty 
for 50,000 miles). But don't get me started on the subject of paying 
"professionals" to do something for you!

----------

And while I'm at it, I'll elaborate on my wife's Audi.  Since it was free, I 
took it in to the dealer for the first oil change...how can they screw that 
up?  I even sent four quarts of my own synthetic oil along, because turbos 
need synthetic (once broken in).  When I got it back, I noticed it had 
waaaaay too much oil in it.  I went to drain the excess and discovered the 
oil pan bolt was overtorqued by well over TWICE the torque spec, and it's an 
aluminum pan!  I drained the excess out and replaced and torqued the plug, 
and then figured I'd check the filter, although how can you screw that up?

Well, you know how a filter looks that's been stuck on a car for 20 years 
and you had to use a giant pair of channel locks to get it off...all mangled 
up and scrunched in top to bottom?  That's exactly what this filter looked 
like!  I thought just about everybody knew that a filter is normally put on 
until it contacts, then 3/4 turn by hand...no tools required, but not this 
"factory" Audi mechanic!  And how did he put five quarts in my car when I 
only gave him 4 quarts (and the car only needs 3.8 quarts?  I can't prove 
it, but I can guess where my synthetic oil went.  The service manager told 
me he had his best man on it.  I told him I'd never be back if that was the 
best he could do, and I haven't been back.  That was nine years ago, and 
I've fixed what few things needed attention on that car, as well as all the 
rest of the cars I drive.

That's just one of the many reasons I don't pay anybody to do anything for 
me unless it involves surgery.  I even built my own house...

Mark Langford, Huntsville, AL
mail: N56ML "at" hiwaay.net
website: www.N56ML.com