Inliners International Forums General Discussion Hi Performance Building a 302 GMC for LSR

I dont think Jim ever experimented with different specs on lobes for the siamese ports and non-siamese ports on the same cam. The life expectancy of those engines was so short, that track time was at a real premium. Jim worked very closely with Mark Heffington,former owner and pres. of Cam Dynamics on developing the cam profiles for the 292's. He ended up using some Pro Stock lobe profiles in those engines. Which at that time was insane by many peoples standards for a 6 cylinder. Most of the fastest records and passes were made with valve lifts of over .900 lift. And that was back in the late 1970's and early 80's when Jim finally hit upon the right cam #'s.And they remained the same from then on.Cams in modern Comp Eliminator SBC's are that big today.The strange sound he was referring to was a "churping" sound the engines made when idling. He always thought it was a combo of the huge Pro Stock grinds on the lobes and the possible reversion of the exhaust and "lump" porting. It never was found to be on any other engines that they did for other people, and those two things were the only differences,cam profile and head. I only know of Cotton's engine ever being on a dyno twice....ever. I saw the second and last time it was. I think kinda' along the same lines as panic,in that those types of different specs would be more apparent on the Minis as opposed to the larger bores and different engine parameters of a larger engine. But, that is also an area that could be researched and proven or put to rest. I know of Winston Cup teams doing that to some of their engines to compensate for "good ports"/"bad ports" on some of their R&D programs, and only found tiny gains in that area(2-3HP typically).So many new things are coming about with the 235's and GMC's with the roller billets I will soon be making for each of them, and now being able to supply a camgrinder with actual cylinder head flow #'s and data, that is now so critical for the best cam selection. That data has never been provided for either engine except for the special few that have the capability to do so. I have spoken to a cam grinder that has expressed interest in taking that flow data and optimizing some grinds for me in developing the billets I will be providing. He also thought that applying the "lump"port concept to these early engines was the most innovative idea he had heard in a long time,and was really willing to work with me and others in this area. I think that before long we will see some spectacular advances done with these engines,especially in the cam and head category....