<VV> Dream engine...If I won the lotto...

Frank F Parker fparker@umich.edu
Wed, 28 Jul 2004 21:04:30 -0400 (EDT)


> 	Give that the motor will be a FI, water injected, inter-cooled,
> high efficiency, twin turbo, the incoming air charge will be much cooler
> (hopefully near ambient temps) than the stock drawthru turbo set-up.
> Much of the heat that a stock turbo encounters is created before the
> exhaust. It is estimated to be a couple hundred degrees before it hits
> the head from the compressor wheel heating up the air due to friction.
> 	I would not run an engine mounted oil cooler at all, but just
> rely on the oversized remote oil cooler, so I could force 100% of the
> cooling air thru the heads.  Proper sealing of the top shroud all around
> the perimerter and careful clearancing of the center fan would provide
> maximum air flow.  Quite possibly a non stock diameter pulley would be
> selected to provide maximum, non cavitating, air pressure thru the heads
> at a specific target RPM.
> Rick Loving
>
My next project is to build a dream turbo engine within budget and
availability constraints. Above sounds like a good approach to which I
will add the following. My stock 180 will arrive soon and I am going to
put on a multichannel datalogger and associated sensors so I can
especially look at production compressor outlets temps vs boost AND
turbine back pressure which is very critical to minmize hot end gases
in the cylinder and thus detonation resistance. Once stock limits have
been determined, then we can see what a modern turbo with special
selected turbine with external wastegate will do to minimize outlet temps
and necessary intercooler size and performance. I had less than 180 deg
out of turbo before intercooler at 17 psi with a TE60 on a nonvair motor.
We will see from the tests but I would not be surprised to see 200+ deg
out of vair turbo at 1/2 the boost- we will see.
140 echaust manifolds that have been extruded honed should help minimize
back pressure and loses before the turbine. A single turbo should work
fine, would have to look at available pieces to see if there really is
a siginificant enough reduction in rotating inertia especially with only
1/2 the exhaust to drive. Suspect there may not be a turbo available at
resonable cost for the exhaust flow avaible and have enough compressor
for hp needed- a guess at his point- no research done yet.
Proper squish with 95 or 140 heads and about 0.045 clearance seems to be
what most builders suggest. Over about 0.075 or so and the squish does
not help any where near as much.
Engine has forged allready and would like to hear from those who have
used oil squirters to cool bottom of piston. Very important to help
the air cooling as much as possible. Racers who have done front oil
coolers- what did u do for those cold starts- a bypass thermostat and
dash 8 or bigger lines??
Using an efi with wbo2 controller so can set desired a/f at normal boost,
then if wg sticks, ecm at higher boosts will flood motor with 9/1 to fuel
intercool. Mazda did that in the 87 626 turbo without intercooler that
my wife had. 120,000 miles without any trouble.
Hard to use a ball bearing turbo on a vair since thay all have water
cooled center sections to keep the bearings within a defined temp
range. Possibly one of the newer ceramic designs.
Finially an stage III Aquamist water/alcohol system that uses a
microprocessor so you can map your water flow vs boost and rpm in a 3D
map just like the fuel.
Ignition and knock control with a Safeguard from Ray and timing control
from the efi controller in my case or a Megasquirt ign controller now
being offered.
Going to start on this some time this winter gathering parts and doing
the tests and design.
Comments, suggestions, additions, things I missed or misunderstood??
Any and all welcomed- been a long time since I bought my Corsa 180 in
1966 and I have forgotton alot.

regards,

frank