<VV> Re: Turbo Alignment

[Jim Simpson]

Just to elaborate a little more on my previous note regarding 
alignment of the entire turbo inlet system -- air cleaner, carb and 
turbo.  The bracket that mounts to the top of the engine just 
provides support.  It doesn't really control the alignment.  What 
I've found is that the rectangular plate welded at the top of the 
turbo inlet pipe is the controlling factor.  If the manufacturer gets 
it just a tiny bit off, it will throw the rest of the alignment off.

That pipe and plate are very rigid and the mounting bracket will bend 
to fit it rather than the other way around.  So quality control in 
the manufacturing process for that pipe is the key.

I'm sure that pipe is set up on a jig before the welding is done, but 
given the typical hurry and low profit margin in such manufacturing, 
I'm sure that the tolerances are pretty sloppy.  I've put two pipes 
side by side -- one that misaligned the inlet path so the air cleaner 
was a couple inches low and one that was essentially perfect -- and I 
really couldn't tell them apart.  There might have been a slight 
difference in the welding of the pipe to the flange, but that could 
easily be due to the difference in manufacturer.  (One was a Clark's 
repro, the other an old OEM pipe.)

The bottom line is that you might have to try a couple pipes to get 
one that is right.

Jim Simpson
'66 Corsa turbo
Group Corvair