|I am very fortunate to have a supportive and
understanding wife. In June 2002 I finished a 6 odd month project of
painting her CRX Si. She understands the merit of nice, paid for,
older cars. We have also moved 3 times since I started on a Rabbit race car which
is now for the most part done. So when I proposed the idea in
early December 2002 for this project she supported it fully.
I found the motor on www.audifans.com marketplace (see links). I am located in VA and it was in
NY so I had to have it shipped. Luckily the company I work for was
willing to let me use their trucking accounts and discounts. The motor began life in a
1985 5000 turbo
automatic. I am told the car had very low mileage for a car this old.
did however decide to fully rebuild the motor. Since cams for this motor are hard to find
and too expensive for my budget I kept the stock cam, but did port the head. Originally
I considered making my own intake and exhaust manifolds, but in light of
how much other things had to get done on the project I just decided to
keep them stock....for now.
There are a few parts I had to source else where as they were
already gone before I bought the motor. One was a shroud and one was
the coolant after run pump. I decided to keep the A/C in my car,
but there will be a pesky turbo in the way now. For now the compressor is
not installed. All other components are still in place I just have
the lines blocked off. I have a Dodge NEON A/C compressor that I
am going to use since it was originally designed for R134a and is
smaller than the York unit that came with the 4000. I will be
mounting it on a custom mount on the radiator side of the engine.
Since it is cool out now the urgency on this part of the project is gone for
My first planned change had been to move the battery to the trunk.
This is a good idea anyway since we already have way too much
weight up front. It also makes room for the waste gate. In
the trunk on the passenger side my car has a little compartment for
tools or such things. I am planning to remove this and put the
battery box between the raised floor rail and the outside wall where
this compartment had been. I decided to put this off until I
already had the dashboard apart for wiring.
In tearing apart the motor I came across one surprise. The thermostat was destroyed.
I have never seen anything like it. It is even a German
thermostat. I found all the pieces either in the thermostat
housing or in the water pump housing. No secondary damage was
done. Aside from that every part removed so far has been in excellent
condition. The turbo's axial and radial run out passed with flying
colors. All cylinders look great and in general the motor is in excellent
condition. The seller of the motor had said it ran very strong
even for a turbo car. I found out why. The lower wastegate hose that
limits boost had a large hole in it. This means the boost levels were well
above stock. It is no big deal as I just replaced it, but it is good to
I was surprised to find that this motor uses 38 mm intake valves.
I guess I had assumed it used 40 mm intake valves like in VW GTI
heads. I was also surprised by how huge the valve stem is at the
back of the valve head on the exhaust valves. I shopped around some for
alternative valves and had no luck. I guess the 2v per cylinder VW stuff is just getting too obscure.
I had thought I might drop the sodium filled valves and switch to
standard VW exhaust valves, but ceramic coat them. The sodium
filled valves are very heavy and as you can see below they have huge
stems at the base. I know the sodium helps manage the heat of a
turbo motor, but the weight and size can't help things. I think
modern thermal coatings on a standard valve might give better overall performance. For those who are interested I go into more detail
on valve weights and sizes in the engine section.
Here is a picture
of the block partially disassembled. I still can't get used to