help! down 100hp on chassis dyno
07-06-2011, 11:00 AM
#21
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I got the car back together and dyno'ed this weekend, and it was the lifters that were causing the problem. I picked up 55HP. The lifters were the problem. It's making 415 to the ground now. Thanks for all the help and ideas.
07-06-2011, 08:00 PM
#22
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Wow. Were they all collapsed? Did they come apart? Hard to believe they weren't making a lot of noise. I'm glad you found it. Was the converter locked on your pull?
07-07-2011, 12:35 PM
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Yep the torque converter was locked up for the dyno pulls. I run open headers so I couldn't have heard the knocking. I'm not sure how to determine how many lifters were bad, my best guess is that the engine sat for 3 or 4 months before I fired it up last year and that a few of the lifters colapsed and didn't pump back up causing the valves not to open far enough. This could be the reason for the low numbers from last year before I put heads on, I had just installed a ***** thumpr cam and it only made 340hp. I never thought to replace the lifters, but the guy that did my dyno work said he'd seen lifters go bad before causing similar problems.
