I have been thinking about a cam change in my 66 (68 Camaro 327 motor). The motor turns out about 300 hp, with an Edelbrock aluminum intake, Crane cam which I believe has a profile similar to that of the 327-300hp, stock heads, headers, and a holley 600 cfm vacuum secondaries carb. I would like to switch to either a Crane or Comp Cams blueprinted 327-350hp cam, to pick up some more hp and torqe. With this change, will I need to change the valve springs, rocker arms, or push rods, which are all stock? The engine was rebuilt years ago, and has seen only a few hundred miles, at most, since the rebuild. Since the car has been sitting so much, I am working on freshening it up. Any other tips or suggestions would be greatly appreciated. Thanks in advance, Dan
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Re: 327-350HP Cam
Factory high performance cams, including solid lifter types use the same valve springs as the base cam because they had soft action. I doubt if the 151 cam will improve on what you've got which is likely more aggressvie than the 300 HP cam.
Check the Extreme Energy series from Comp Cams. They have aggressive action (acceleration) and require stiffer than production valve springs.
Duke -
Re: 327-350HP Cam
Even though the 327/350 has always been a good cam it is 35 year old technology. Modern asyemmetrical profiles will give you more power in both hp and torque, smoother idle, improved vacuum, better throttle response and even better mileage. Unless you need the cam to be correct for judging I would go with year 2001 technology.Comment
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I Wouldn't!
I'd go with what I have experienced as the most awesome torque imaginable that I've ACTUALLY FELT in the seat of my pants. This is in comparison to all the other small blocks I've built over the years.
Shade tree trial and error will always prevail over bench racing and reading cam specs. See the archives for lots of data on using the 151 cam.
Dale.Comment
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One more question...
What about the new Crane or Comp Cams blueprinted muscle car cams, which are supposedly "smoothed" out for better all around performance? Thans, DanComment
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Re: One more question...
I supposed "blueprinted" means they are ground to closer tolerance, but who knows if that really makes a difference in performance.
I don't think you can go wrong with a factory cam. Chevrolet put a lot of research into them, they provide excellent performance, and use standard valve train parts with OEM durability. For a vintage Corvette I would not go any other way, but if you're looking for a better torque curve a modern fast action cam with stiffer springs can do better.
Scroll down the page to the thread titled "dyno numbers- cabin fever" for some comparisons of the factory mechanical lifter cams with a modern Comps cams grind.
DukeComment
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I measure every lobe on the cams I use.
and I've observed 0.006 base circle run-outs on Comp Cams extreme energy series. I've seen duration variances on Crane stuff that's rediculous! 0.006 inch run outs will chew up a set of lifters in about 15,000 miles! I'm totally disgusted with the so-called tight tolerances and high quality claims of those two manufacturers.
I've had good luck with all the Melling cams I've used and I REALLY like the quality of Ultradyne cams from Mississippi.
Dale.Comment
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