[DeTomaso] DeTomaso Digest, Vol 38, Issue 22- COMPRESSION RATIO

[RCBSONS1 at aol.com]

First I did break my motor but it was only the water pump
impellor that fell apart causing what I thought was also a
blown head gasket.... no bad gasket... checked everything
else and put a new set of springs and seals back and it is
running again.
 
My compression is 9.6 to 9.8 to 1
My builder stated we could go up but (Art are you 
reading this) then the life of the engine goes down
We are talking a 20 hr track time motor vs 40 to 60
hours of what I wish to clarify (hard running time...
like you drive on the street Art)  I have one Shelby buddy
with a 331 at 500 hp same compression as mine and he
has 80 plus track hours on his motor (uses and hour meter)
he runs only pump gas 91.... he will be rebuilding this
winter as he is on borrowed time.
 
Yes Hp goes up with compression but as Garth stated
you can build 550 to 600 hp motors without going way
up in compression unless it is injected which will let you
go a little higher.
 
I do use race gas when I track the car but only 40 to 50% just
to lube the valves and keep them from rattling... my motor is a 7500  rpm
motor but I run the rev limiter (which I bounce off a lot) at 6800
this also lets the motor live a little longer. I also learned that 
the rev limiter does not work in a downshift so use the damn brakes
 
My car is not a full race car like the Escahoff 13 1/2 to 1 car
It is nice to drive on the street and pull up to the pump and 
filler up... You can also do short blasts here and there but
I can tell you with close to 600 ponies 140 plus comes up
real quick.... Save your real hard driving for ORR or the track
sweeten the gas and detonation will not be a problem... plus
it is a lot safer with helmets (flame suit) and people to help
standing by if a problem does come up.   Most of my Shelby 
buddies do not use any other gas other than 91 pump gas
I just do it because it is like an insurance policy for my motor
 
My 4 cents
 
Bob Benson



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