2007 Chevy Avalanche cam swap
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2007 Chevy Avalanche cam swap So I have been working on this truck for about a year now. So far this is what I have:
-stock 5.3 with 4l60. 4x4
-243 heads have been machined with radius valve job, dial .660 springs, Harland sharp sls17 1.7 rockers, and tsp 7.4 chromoly push rods
-dod and arm delete with ls7 lifters and new valley cover
-Brian tooley 3 bolt cam gear with chain dampner
-summit high lift stage 2 truck cam #8720r1
-Gibson cat back single exit exhaust
-volant cold air intake
that all being said, I did send the computer to be tuned with the cam card an had the dod and arm deleted. After reinstalling the computer and finishing this all up, I cleaned the throttle body and checked for vacuum leaks and all is good. Here is my problem, I am not getting the throttle response I figured I would get. I don’t feel like I increased in power at all. It’s a dog off from a stop and somewhat bogs when shifting gears. I also feel that the rockers are making more ticking noises that they should. This is my first ever build and need a little guidance. I would love to hear what or where I have god wrong and love to hear from the folks at Summit Racing have to say. Thanks in advance. Also, I might have left some info out so feel free to ask questions thanks.
-stock 5.3 with 4l60. 4x4
-243 heads have been machined with radius valve job, dial .660 springs, Harland sharp sls17 1.7 rockers, and tsp 7.4 chromoly push rods
-dod and arm delete with ls7 lifters and new valley cover
-Brian tooley 3 bolt cam gear with chain dampner
-summit high lift stage 2 truck cam #8720r1
-Gibson cat back single exit exhaust
-volant cold air intake
that all being said, I did send the computer to be tuned with the cam card an had the dod and arm deleted. After reinstalling the computer and finishing this all up, I cleaned the throttle body and checked for vacuum leaks and all is good. Here is my problem, I am not getting the throttle response I figured I would get. I don’t feel like I increased in power at all. It’s a dog off from a stop and somewhat bogs when shifting gears. I also feel that the rockers are making more ticking noises that they should. This is my first ever build and need a little guidance. I would love to hear what or where I have god wrong and love to hear from the folks at Summit Racing have to say. Thanks in advance. Also, I might have left some info out so feel free to ask questions thanks.
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That's more cam than I would have chosen for such a build, personally. You've sort of backed yourself into the "not enough motor" situation... after all, there's no such thing as too much cam, only not enough motor. Your description of how the motor runs - no "leave" - is the textbook classic complaint that results from it. But, it's done now, so might as well work with it and try to improve, rather than just say "it's bad" or whatever.
Can't comment very specifically on "ticking noises". When you used your adjustable push rod to set the lifter preload, what did you set it to? What was the length that gave zero preload?
I think the most logical thing at this point would be a good quality higher-stall torque converter (maybe 3000 - 3200 RPM) such as from Circle D or Yank, and maybe gears. Especially if you have 3.42s, and even more especially if you've put bigger tires on it. But gears on both ends of the truck are kinda $$$. Also, getting it tuned either live, or via log files, would almost certainly help, especially the shift recovery problem.
Can't comment very specifically on "ticking noises". When you used your adjustable push rod to set the lifter preload, what did you set it to? What was the length that gave zero preload?
I think the most logical thing at this point would be a good quality higher-stall torque converter (maybe 3000 - 3200 RPM) such as from Circle D or Yank, and maybe gears. Especially if you have 3.42s, and even more especially if you've put bigger tires on it. But gears on both ends of the truck are kinda $$$. Also, getting it tuned either live, or via log files, would almost certainly help, especially the shift recovery problem.
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I also think it was too much cam but summit reassured me several times that it is the perfect cam for someone like me that does a little towing but mostly daily driving. How do I tag them in this thread so that I can get their opinion.
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From: Ohio, Georgia, Nevada, Texas
Do you remember if you talked with phone sales? We don't see your inquiry hear but may be mistaken. 8720 will work for occasional towing and is as big as we recommend without converter but a 5.3L in a heavier 4x4 with stock converter comes with it's own complicaitons that hold it back out of the gate. If it's soggy, we think its likely tune related because it should run hard once in the 3000 on up powerband. The Gibson single back isn't helping matters much. Duals would definitely offer a lot more power. Headers also recommended. Both things are preferred any time we introduce a larger cam with any overlap at all. As for the tune, when you say the words "towing" "87 octane" "trailering" "pushing snow" or anything like that, a tuner is going to pull 5 degrees or more timiing out of our tune. And for good reason. We do have smaller cams like the 8719R1 that might have been preferrable here for the combination as it stands, but we think a lot of what you have can be fixed to make the bigger power numbers 8720 is capable of. Also, we'd recommend a factory rocker with a trunnion upgrade. Afterarket rockers are heavier at the valve and will float a little sooner. Let us know your thoughts and we'll get you fixed up.
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From: Monroe,NY
I think that cam is to big for such a heavy vehicle. You really need to get someone to tune that in person. You are also hurting yourself running the stock exhaust manifolds. My opinion you should go with a smaller cam or you will need a torque converter and probably gears. Does it at least feel powerful above 3500 rpm's? If not the tune could be the biggest problem. As far as the ticking you may have the wrong length pushrods.
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Agree with the others. Assuming stock tires, you'd want 4.56s, long tube headers and a ~3k stall for that setup. The Avys are 6000+lbs with a driver unloaded, so a milder cam would've worked better with the 5.3L. But it should've started picking up in the mid-range or something is off.
