[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

Re: [T3] No. 2 Exhaust Valve Problem - Update


On 3 Sep 2002, at 10:28, Jaranson, John (J.W.) wrote:

> Upon closer inspection, it looks like I ground the seat for #2 exhaust valve off
> center a bit.  This has led to the guide wearing and the valve pounding out the
> seat.  I did the valve job myself using three separate (15, 45 and 75 degree)
> carbide cutters.  I remember having a difficult time getting the cutter guide
> pin into one of the guide.  Could easily be this one.  Not sure.

Seems like a reasonable theory. You may be able to replace the guide and 
then redo just this seat and salvage the head. It's not really so bad.

It is normal also to run a reamer thru new valve guides. This sizes them 
properly and also serves as a check that the bore is straight. I had a guide 
that I installed once and had a bit of extra trouble. It finally went in and 
seemed okay, but the reamer never felt quite right. I had bent the guide and it 
just wouldn't work right until I replaced it. I was lucky to find this before I got 
the head on the engine.

> BTW, the Hi-Rev springs that I had in there were at least 3/8" longer
> (uncompressed) than the stock springs.  

Uncompressed length really doesn't tell us much.

> Also the wavy pattern on the cylinder to head mating surface that lead to my
> blow-by problem.  It was in the head surface, not the cylinder.

Okay, that's a relief. I've never seen cylinders which were done poorly here, 
so I'm relieved that it was the head end. I'm just surprised that this could 
happen like this without your being aware of it.

BTW, I do my flycutting on a milling machine. This makes for a much more 
rigid setup. I've used the bolt-on flycutter with success, however, but you 
need to keep the shaft lubed and follow their RPM directions. The latter 
applies to cutting on a mill, too.

> Also I have the stock adjsuters in.  Decided not to monkey around with all
> the geomtry changes necessary for the swivel feet adjusters.

The stock adjusters can be misleading at times because they develop flats 
on their ends which can make adjustment tricky. This might make it seem 
like you had to back the screw out more than things really moved.

-
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

------------------------------------------------
To unsubscribe, E-mail to: <type3-off@vwtype3.org>
For more help, see http://vwtype3.org/list/

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]