10k in pocket. New block or EFI ?

[olddog]

Originally Posted by Barry_R

I have run the same 505 inch, 676 horsepower FE engine on a dyno with both multiport EFI and a carb. Documented in Hot Rod magazine in 2004.

Same intake - a converted Dove single four barrel. We never touched a thing on the package - unbolted the throttle body and bolted on a 950HP, unplugged the injector wiring from the harness and hooked up fuel to the carb.

Based purely on airflow the EFI throttle body should have won. It didn't. A statistical dead heat - but the carb had single digit higher peaks on both torque and horsepower.

Testing done at Wheel to Wheel Powertrain - at the time one of the foremost EFI tuning facilities in the country. The EFI is better at almost every non-WOT and transient driving parameter - but peak power is not one of them.

Barry - I'm not trying to argue the point, but would like to learn from your extreamily interesting (to me) test. Was the intake manifold dual plane or single plane? Was there a measure on the AFR to see if that could explain the difference? Was the timing exactly the same?

I have a MassFlow on a 347 stroker, which uses an Edel Vic Jr carb intake with EFI bungs welded into the ports. MassFlow claims that it will only work on a single plane intake, and that with no fuel in the manifold that the typical poor low end torque does not happen. Maybe, but it seems to me that an intake designed for a wet air stream would not work as well as one designed to run dry from the get go.

Also the webber look alike with individual throttle plates that close to the head ports is a whole different ball game.