Stock cam timing question
September 19th, 2018, 06:43 PM
#1
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Stock cam timing question
I'm looking at the cam specs in the 1967 service manual. The intake shows to begin opening at 21*. My Comp cam shows intake opening 25* at .006.
Is the stock cam measured like the Comp cam or maybe from .000?
Is the stock cam measured like the Comp cam or maybe from .000?
September 20th, 2018, 04:33 AM
#3
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September 20th, 2018, 06:53 AM
#4
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Which is exactly why the factory timing numbers are suspect. It's extremely difficult to measure first motion of the lifter on a cam lobe. Also keep in mind that it isn't just duration and max lift that matters. It's the area under the curve that determines total airflow. The classic example of this is the NHRA stock class "cheater cam". Same duration and lift as OEM, but much more aggressive ramps on the lobes.
September 20th, 2018, 07:27 AM
#5
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It does.
I'm putting together a 455 with a Comp XE262H cam and I was trying to determine the delta for lift and duration between a stock cam 330 or 400 4B w/AT and the Comp cam.
Thanks for the info.
I'm putting together a 455 with a Comp XE262H cam and I was trying to determine the delta for lift and duration between a stock cam 330 or 400 4B w/AT and the Comp cam.
Thanks for the info.
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