Norm Schenck at Competition Fuel Systems has been dyno testing Stromberg 97 and BIG97 carburetors for us for year. In fact he had a major hand in developing the BIG97 from scratch.
We set up a dedicated dyno motor at Norm’s facility in Vassar, Michigan and we’ve been watching intently as horsepower has grown with small tweaks to the carburetion and heads. This set up is with the cast iron vortec heads, that Norm ported himself. We have a set of AFR CNC ported heads waiting in the wings and they would probably make more power, but Norm suspects that the limitations of the Edelbrock tri-power intake would not have allowed for much more flow than was achieved with the vortec heads.
Want to know the numbers? This is a GM 330 horse crate motor and the best we got this time (by taking off the mufflers) was 404 ft-lbs of torque at 4300rpm and 386HP at 5400rpm. We still made over 400/380 with the mufflers on. This was on 89 octane gas with top end A/F ratios all in the 13s ! The dyno can now read separate A/F ratios per cylinder.
What this motor will do once someone (ie us) develops a new intake for the BIG97s is anyone’s guess. But it will be impressive, you can be sure of that…