How much cam lift
06-02-2005, 01:20 PM
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How much cam lift How much cam lift and duration are safe for a stock '94 al. head motor? It's an auto and once i determine my cam limits I can build around that.Thanks.
06-02-2005, 06:00 PM
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Set the goals first, buy parts second... measure twice, cut once. Lifting the cam to within a fraction of contact will do no good if your heads don't flow much extra after .5xx lift. So you'd be hammering the valves for nothing. If you are going to spend $ on heads you want to have the whole thing researched first. If you're going to add a cheap used 'blower, then you can do something different with the cam to help the FI, and so on...Set the plan first instead of throwing a big cam...you'll be happier.
06-02-2005, 08:17 PM
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I'm going to disagree just a little bit. Very large dyno numbers have been had from some cam only LT1's with the bigger cams (cc306, gm847, gtp-6, etc) vs smaller cams like the cc305, hotcam etc. Yes the heads are the greatest bottleneck in the LT1 design, but a large bumptstick can compensate and make close to 380rwhp cam only, with an aggressive high lift (.560"+) and large duration (230+).
But in reference to your question, assuming your heads aren't milled, and you are using a stock thickness head gasket you can run up close to .600" of lift before piston to valve clearance becomes a problem. A dial indicator is very important here.
As a side note, if it were my car, I would call up LLoyd Elliot and talk to him about a setup. He can sell you a matched heads and cam setup that suits all your needs with zero guess work involved all for a fair price. Don't forget that you will need a stall that is suited to your setup and wants.
Think of an et goal though instead of a HP goal. Much easier to figure out what you need. sorry for the long post...[rant off]
But in reference to your question, assuming your heads aren't milled, and you are using a stock thickness head gasket you can run up close to .600" of lift before piston to valve clearance becomes a problem. A dial indicator is very important here.
As a side note, if it were my car, I would call up LLoyd Elliot and talk to him about a setup. He can sell you a matched heads and cam setup that suits all your needs with zero guess work involved all for a fair price. Don't forget that you will need a stall that is suited to your setup and wants.
Think of an et goal though instead of a HP goal. Much easier to figure out what you need. sorry for the long post...[rant off]
06-04-2005, 06:36 AM
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Thank you that is what I was looking for. I understand the dynamics involved in changing one part or a series of parts for a goal. I just did not know how much lift was safe on a stock LT1.
