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Re: [T3] Valve Adjustment Questions


At this late date, anything could be mis-assembled on your engine, chances are 
it's been rebuilt one or more times.  The valves need to be adjusted at piston 
TDC, you can pull a plug and verify that the TDC mark on the fan is really TDC 
on the piston.  The fan is keyed to the crank so there's no reason for it to be 
otherwise.  You can also check to see that the distributor is assembled 
correctly with the #1 mark on the distributor rotor.  What you can't do is to 
check to see that the cam is correctly assembled without pulling the engine and 
oil pump. If you've got something other than a stock cam, all bets are off.

When I got my square, the PO had installed the distributor like you would for a 
bug, he said he'd pushed it all over town and it hadn't started(duh).  I 
wouldn't assume anything is correctly set, I'd go through the book and check 
everything that can be messed with.  I had to go around several times the first 
time I adjusted valves, the PO had screwed the valve adjusters down tight(said 
he was a "Chevy man", whatever that means).

The valve gap exists because of the different rates of expansion among the 
various metals making up the engine.  If you get it too tight, you can burn a 
valve, too loose and you get battering of the valve train and low power.  On 
standard pushrod engines with no hydraulic valve lifters, there's usually a gap 
that's set on them.  The air-cooled VW engine has a lot more in common with 
aircraft engines than the common water-cooled engines in cars these days.

I don't have Muir memorized, but I though he explained the whys and wherefores 
of valve adjustments.  Guess I'll go have to dig it up and see what he missed.

My procedure is to start with #4 valve set, then go 3,2,1.  I also use a wrench 
on the generator pulley nut to crank the engine around, I've seen too many 
pieces of T3 engine tin that have been totally messed up around the timing plug 
hole from guys trying to use a screwdriver to bar the engine around.  Takes 
about 5 minutes per side on my beast doing it my way.


>         I was adjusting my valves today for the first time, and all went
> well with #1, but then when I rotated the engine as Muir says to (i.e.
> 180 degrees from TDC#1) I noticed that the two valves for #2 were offset,
> so I turned the engine clockwise until both were even, which was about an
> inch (on the crankshaft) off of where it should be according to Muir. 
> So, should I go by what he says or by how the valves look?  Would the
> notches be off because the dist is installed incorrectly?  I've already
> adjusted them assuming that I need to adjust them when they are both
> closed in firing position, but I wanted to make sure before I did
> anything else and/or continued on with the #3 and #4 valves.
>         One concern I have is that the valves on #1 & 2 were quite tight,
> with #2 requiring me to turn the adjusting bolts on both valves maybe 3
> or 4 times before the .006" gauge fit.  Is this anything to be concerned
> about?  What could cause this to occur besides someone not gapping them
> correctly?
>         Could someone explain why there needs to be a gap, and why its
> size matters?  I like to know the hows and whys for curiosity's sake, so
> I'm not just doing as told, and because it makes figuring out what is
> wrong, what to do, etc. easier.  Anyone know a book I could get that
> would explain all these sorts of things?  Or a resource of any sort?
>         Thanks in advance!
> 
> Sincerely,
> Christopher J. Valade
> 




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