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  #21  
Old 08-28-2012, 07:08 AM
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I have ICL at 106, LSA at 110, Duration at .050 is 240 and 246. I don't see a spec for duration at .004.
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  #22  
Old 08-30-2012, 01:24 PM
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More specs:

duration at .006 283/300

Gross valve lift is .508/.511 but with 1.6 rockers that .542/.545

Comp cam claims I shouldn't have issues with vacuum but I told them at 10.5:1 compression. The seller told me that's the compression but I am trying to research the piston installed and head CC to confirm that. I have not run a compression test yet but I will be doing that next.
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  #23  
Old 08-30-2012, 01:58 PM
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Hrmm... maybe you have a vacuum leak somewhere. Still, that's a big cam for a cruiser. JMHO

My 2000 Z28 that ran high 10's - full weight, drag radials, through mufflers... did so with a 228/236 @ .050" duration cam in a 347" LS1. It had great manners and pulled 17-18 inch/hg of vacuum. (factory cam was 20-21 inch/hg for comparison) It was a Crane cam, I had a Comp Cam in it previously that made less vacuum (12-13 inch/hg), made less power, and had lots of cam surge unless I kept the RPM up. That cam was 238/242 @ .050"

I could go on about cam stuff, but I feel we need to figure out your vacuum problems for now.
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  #24  
Old 08-31-2012, 08:36 AM
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My main concern right now is getting the brakes improved. If indeed the vacuum has always been low (when previous owner first built the motor-which I am trying to find out) then I can focus on getting a vacuum pump or hydroboost. However, if indeed there is a leak or some other mechanical issue, I’d rather resolve that issue and not put an expensive bandaid on the problem. Other than a leak at the carb or manifold (I check hoses and no leaks), what are some other possibilities?

What is the best way to identify leaks at the carb ? and intake? I don’t want to start ripping things off.
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