tinymikey (1/4/2009)
Any idea what these new castings might be worth in power gains, say single four barrel versus a 6-71 blown drag engine?
This is a new topic so I've taken this opportunity to make a new post with it.
John hasn't thrown any numbers or expectations out there yet. Testing will determine this but with improved out of the box flow numbers over the stock heads then an increase in performance is also to be expected. But raw air flow numbers are never the whole story as improved valve locations, combustion chamber design, and port configurations also play a large part in overall performance. With the combustion chamber cc’s being downsized to compensate for the inefficiency of aluminum in regards to heat retention, then at least the gains from the other improvements will not be offset or taken away by the use of aluminum. It will also make sense that for the anticipated increase in air flow for the new heads to be fully taken advantage of, the camshaft, intake manifold, ignition, and exhaust all must be upgraded to match. Just putting the new aluminum heads on a dead stock engine may or may not see any significant gains in performance but testing will help to quantify this.
Lorena, Texas (South of Waco)