Posted by george on January 11, 1999 at 05:47:16:
In Reply to: Does anyone know the lift, duration and lobe centers for the 251's cam? posted by Chris on January 07, 1999 at 20:54:47:
I am very interested in your calculations and input data. When you collect all this, let us know the full summmary of valve timings etc.
I am especially curious about the valve timing changes that were made during the 50s on the 230 engines. In cars, and I think the trucks
too, the torque peak moved from 1200 up to 1600 as a result of shifting to a "hotter" cam. But I don't know what the actual difference
in valve timing was.
Also, what are the specs on the reground cams you can get today? I have hesitated to do this because I could not get information on what
the vavle timing would be, which meant I could not estimate the new torque peak. Given the limitions in RPM of these engines, pushing the
torque peak too high would be clearly counterproductive.
FYI...check these programs by Bowling. And check a browser, I think he has some other sites also.
http://sura1.jlab.org/~bowling/auto_noframe.html I have used these to estimate the effect of raising the compression ration from 7 to
about 8 (roughly gained by milling head 060). This looks to be a pretty effective and cheap way to increase horsepower.