Quote:
Originally Posted by Jim Robertson
It was a great day at the dyno. Having an opportunity to rework a numbers matching HO when most engines in the shop are race engines was a distinct pleasure. Posts in other threads have given specifics about this one but know that we used most original parts. The only parts intended to upgrade performance were the cam and rocker arms. The cam is our version of the famed RAIV flat tappet hydraulic with about 230/240 degrees duration at .050" tappet lift. The rockers are a stamped steel replacement RAIV with 1.65:1 ratio. The rods are forged Eagle H beams with stock dimensions. Pistons are custom made by Diamond with ring lands moved down to stay away from the rust pits found at the top of two bores (see the story about this in the HO thread.) Valves are stainless steel from REV with very near stock dimensions. The heads are unported but have our highly refined three angle valve seats. They max flow 240 cfm but achieve that number very early in the lift cycle. Intake and exhaust manifolds are untouched. Compression calculates to just under 9:1. She's a keeper...
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How did you get "up to" 9:1 ?? deck the block? shave heads? why not a roller tip stamped steel rocker at 1.5 ratio? new pushrods, or clearance for the old ones? just some thoughts I had...