I am trying to get rpm out of my motor. For some reason my motor starts losing power at 6800 rpm. The motor is a 509 c.i. BBC with a 4.500-inch bor and 4-inch stroke. Heads are Dart big Chief running a Dart single plane manifold and one 1150 Dominator on methanol. I am running a special Eagle Racing Engines cam with about .800-inch lift and 280 duration at .050 lift. JE pistons 14 to 1 with standard rings. I am using steel valves in the heads but I'm running large springs with almost 300 lbs. of seat pressure and 800 lbs. at lift.
The motor made 705 ft. lbs. of torque at 5800 and 835 hp at 6800. In my class (S/E) I need to make at least 900 hp, since we run at Fallon (Nevada) Raceway and it is hard to run the number there at times. I have an RE dragster and traction is not a problem.
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Kurt,
In
my opinion, the combo you describe should
be making a lot more power and torque.
Methanol/alcohol is an excellent choice,
but can be temperamental.
My
first concerns are carb and fuel delivery.
Is your carb a re-worked alcohol 1150
or just an 1150? An engine of this potential
needs all the carb that you can throw
at it, especially on alcohol.
You
should also be using a belt-driven fuel
pump with a regulator and return line
to properly feed this engine.
Scott
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I am beginning the planning stages of a project car -- a '72 Cutlass Cruiser wagon. It will be street-driven. It has a stock 350, 2 barrel arrangement, with a very mild aftermarket cam from the previous owner. I plan on converting it to a manual transmission.
My goal is head-turning street performance (possibly with a mild power-adder like a street blower, etc.) with a good compromise on maintenance and durability. I'm having trouble coming up with a good set of criteria on my own to determine if I should build up the existing engine/drivetrain or scrap it all and put in a completely different combo.
Can you help me prioritize the most important considerations?
