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What will be the right seat presion on a hydraulic roller camshaft with 220 duration at 0.50 and 5.20 lift. I have two sets of springs, one with 130 seat and 330 open and another set with 165 seat and 390 open. Are any of those ok or any other suggestion?
thanks

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I would look at the amount to coil bind first and use the one that was at least or close to .080 from coil bind I did one 426 street hemi motor with a hydraulic roller cam and lifters and used 165 lbs on the seats and 375 to 390 lbs opended, motor revs good and pulls hard to 7000 RPM, maybe a little higher The customer wants it shifted at or below 6800 RPM, so that is where it gets shifted at by him. it is a 4.25 stroke Pulls like gang busters

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To properly answer your question, it would help if you gave all pertinent information including application. Unless your just throwing together parts you have laying around and have no longevity or performance expectations. (I.E.-it is what it is)Based on your question, you don't fully consider valvetrain as a 'system'. This can lead to bigger problems ($). Measure all the springs and be familiar with their typical load losses before selection time. As was mentioned you should pick a spring that runs near C/B. Production stuff can be engineered to run at 1mm from C/B. I've run 'racy' springs below 1.5mm.

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