<VV> Re: 1966 Turbo

[Chris Hames]

On my 65 turbo, I had a big time getting it to make boost again.

The biggest concern of mine is that you said the intake impeller  
spins independently of the exhaust impeller.  That suggests to me  
that something inside the turbo isn't right.  Get your shop manual  
and read the whole section on rebuilding the turbo.  It really helped  
me understand how it worked.

There's a spring plate that makes contact with the backside of the  
turbine impeller when the exhaust housing is off.  This spring plate  
is pushed out of the way when the exhaust housing is tightened up  
against the compressor unit.   You can compress the spring with the  
housing off though, but you'll have to have a third hand to spin the  
blades for you unless you're really good :D

If you can put the exhaust housing on the turbo and there's no  
contact with the spring plate, your housing could be shot.  Although,  
clarks sells some really big shims (C5705, pg 44 big catalog) that  
you can put in the housing to get the housing to push on the spring  
plate again.  I don't really like that solution, but it's what's in  
my car right now.  I think you would have to compensate on the inside  
of the compressor with some other shims to keep the exhaust turbine  
blades in the appropriate place though, but I'm sure someone will  
correct me if i'm wrong.

Like has been said, make sure you've got no exhaust leaks.  Go under  
the car in the morning and coat every joint in the exhaust piping  
system with soapy water and then turn on the car and look for  
bubbles.  Make sure the turbine housing is seated and sealed properly  
to the exhaust intake.  I got a short length of hose from turbonetics  
that matches my plugwires and looks really slick to go between the  
turbo and the intake manifold.  I feel it seals better than the one I  
got from clarks.

Make sure there's no vacuum leaks into the carb either, there's a  
bunch of hoses connected to pcv, throttle body, and air cleaner, just  
make sure those are all a.o.k.  Some of mine weren't.

Make sure your carb is tuned/jetted/rodded correctly.  The top of the  
metering rod arm should be flush with the top edge of the float bowl  
when you're pressing down on the accel pump spring until the bottom  
of the topmost spring makes contact with the rod arm.

If you have the turbo on the car, and the car can run, disconnect the  
exhaust outlet to muffler pipe, turn the car on and look to see if  
the impeller blades are spinning at idle.  They should a little bit.   
I don't recommend holding your head there long though :D

Big problem area for me, make sure that your v-clamp is holding the  
exhaust housing to the rest of the turbo properly.  On mine, the  
circle of the exhaust housing out and the circle of the turbine  
impeller weren't lining up, and if I wasn't careful and just clamped  
it down the turbine impeller would bind on the exhaust housing.  I  
kept this in check by assembling the turbo on the car without the  
carb, and then sticking my finger in the intake side of the turbo to  
make sure that it was still able to spin.

Freely, by my assembled definition, means that you'll be able to keep  
it going with your finger, but if you "fling" it, it really won't go  
more than 1/2 to 3/4 of a turn.

So, when I got to this point, I had some boost - but not a lot. (2-3  
psi on a VDO gauge, about 1/4 of the way into the pos side of the  
stock gauge). I replaced the points with new ones from Larry's  
Corvair in Gardena, CA, the plugs with NGK B6HS gapped .030, a new HD  
distrib cap, 8mm silicone plug wires, and a flamethrower II coil  
(Larry's too).  This gave me a lot more boost back (4-5 psi, 1/2 way  
to positive), but I still had issues in the top end.  Then I replaced  
my engine compartment harness, as I was having some strange  
electrical issues at the same time, and this had the wonderful side  
effect of curing the top end boost issues too (now I get 6-7psi, a  
little above halfway on stock gauge.)  And, replacing the harness  
cured all my little electrical gremlins too.  I just got done  
replacing all of my harnesses and important wires (except that  
expensive fuse block one.)  I bought all of them but two direct from  
the manufacturer at wiringharness.com.  They ship really fast and  
have their catalog for corvair available online.  It's the same  
harnesses you buy from clarks and larrys, just cheaper cause you cut  
out the middleman.

These guys mean what they say when they tell you your ignition system  
needs to be "perfect."  On a side note, I don't like the electronic  
ignition stuff, points work great, if not better IMO.

Timing at 24 degrees BTDC.

One other important thing, as I was fixing the car - I stayed away  
from throwing "band-aids" at the car until I systematically  
eliminated problems one by one.  Wherever possible, I tried to get  
the car back to a "like stock" situation before I added more junk to  
the car in an attempt to control problems.

Other advice?  Get a safeguard, once they're available again.  I  
can't wait to get mine, and I must say that Ray Sedman is a very  
knowledgeable guy who was an incredible help to me while I was trying  
to get this whole turbo thing figured out.

Wow, long post...but this is pretty much a summary of the last three  
months of my life :D

Good luck, feel free to as me any questions too.

Chris
65 Corsa Turbo with saginaw 4spd.