<VV> Advice on a '65 Turbo?

[Tony Underwood]

At 12:11 AM 6/25/2011, Frank DuVal wrote:

>Actually running 140 or 110 heads on a turbo require premium plus
>gasoline. Aviation  gas or racing gas would be nice.  A Safeguard should
>be a necessity to avoid engine damage from detonation at boost with pump
>gas. But it will run great! I have driven a 140 with a turbo. I only
>dropped two valve seats in one trip around one block in a city!


Even a stock turbo engine is going to be rough on its factory valve 
seats at this time and age.   After all those years, ANY Corvair 
turbo engine is going to have questionable heads.  If you wanna keep 
seats in the heads of any turbo engine that's not already been 
subjected to a going-through, don't press it into boost.   It's that simple.

Best route:

Break out the wallet and have the seats replaced with deeper 
seats.  There is someone (actually more like someseveral) who do/does 
this work and does it well.   I've seen a pair of 140 heads with deep 
seats on a modified turbo engine get flogged HARD and the engine 
never shed a seat.   If it had been a factory stock pair of heads, 
they wouldn't have lasted through the first day of flogging.

Like Frank said, you'll have compression issues and it's going to be 
difficult to find gas good enough to run right without having 
enormous problems with detonation.   Take it from me... a bunch of 
boost with less than outstanding gas even on a low compression engine 
(with 8-1 compression 95hp modified heads) can result in high speed 
detonation that isn't that easy to actually hear when the engine is singing.

But you'll sure know about it later.



>Really
>fast and then repair time for the owner. He was not pleased.... He said,
>once he had the head work done at Moby Dick Racing ( remember them?),
>the car was faster than his V-8 Corvair.


A correctly set up modified late turbo engine in a light weight 'Vair 
will indeed be a surprising ride.   But that power is going to come 
at a price.  You're going to have to pay it if you expect the engine 
to put out what it actually is capable of producing when 
turbocharged.   Well... if you expect it to stay alive for more than 
a week...



Like Frank said... HIGH TEST.   You simply can't live with anything 
less.   That means the highest grade fuel you can get.  If you don't 
mind shorting your local governor out of road taxes, find a source 
for race fuel... sneak some cans of the stuff away, or make friends 
with a local racer and get him to supply you.   It's going to 
cost.  And if you get caught (unlikely unless you're quite stupid) 
you *could* end up in some trouble if you awaken any sleeping dragons 
in your area...

The alternative is to resort to electronic engine controls (ala late 
model vehicles that depend on such for their performance) to control 
detonation.   Or both.   That line from "Mad Max" always rings through...

"Speed costs money.  How fast do ya wanna go?"

One thing to remember is this:

You are dealing with an engine design that is well over a 
half-century old.   It was originally intended to p[ower a small 
light weight sedan to and from the grocers and schools and take 
grandma to church.   Now people are trying to extract two horsepower 
per cubic inch out of it... and some are doing it.   But like the old 
nitromethane fueled 392 Hemi engines in those early top-fuel 
dragesters, the engine becomes a "seven second hand grenade".

Heat is the enemy, and the Corvair engine simply does not have enough 
cooling fin area to endure such high outputs for very long without 
cooking it.   And, turbocharging is by far the best way to heat an 
engine very quickly.  Extracting power depends on making the engine 
as efficiently cooled as you can make it.   And even then, you're 
fighting an uphill battle... literally.

You'll find it very easy to drive the engine into boost during a long 
hillclimb on the highways if you're in a bit of a hurry...  such as 
the grade going up Christiansburg Mountain on I-81 in Montgomery 
County VA.  THAT stretch of highway will make boost in 4th gear just 
trying to keep up with traffic if you don't watch things.  And if you 
stay in it for the 3-4 minutes it takes to top that grade you can 
expect engine temps into the *emergency* range and the valve seats 
are going to be looking for an escape route if they've not already 
been told to behave by one of the Gurus who can teach them the errors 
of their ways.   And yes you CAN ask me how *I* know.



tony..