06 ls2 cam in 01 lm7
On The Tree
Joined: Oct 2011
Posts: 102
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From: Dirty South
Same problem I had with Mythbusters. Most articles are too hung up on their own hunches and change multiple variables at once without following a real scientific process. Frustrating because you read or watch the whole thing, they declare victory/defeat/learned something, and I feel like it was just a big inaccurate and inconclusive waste of time.
-BUT- that article gave me hope. It's far from flawless but about the furthest in the right direction I've seen in some time.
So let's contemplate this question: If the feeling in the thread is that better springs are needed for aftermarket or the LS2, assuming springs will be purchased, why are we so down on a gain of 67 lb-ft (78 hp) for a few hours of work and some factory parts that can be gleaned from a junkyard? (ok; a harness that you can buy affordably or extend yourself for a dollar in wire)
Better cams exist for sure but 78HP in an afternoon is not bad IMO if budget is a constraint.
If float is a concern, what's wrong with LS2 cam, LS2 springs and shift at 6250-ish? Gains at 5,500 are still significant: +46 lb-ft (48 hp). At 6000 we are probably up ~65HP.
-BUT- that article gave me hope. It's far from flawless but about the furthest in the right direction I've seen in some time.
So let's contemplate this question: If the feeling in the thread is that better springs are needed for aftermarket or the LS2, assuming springs will be purchased, why are we so down on a gain of 67 lb-ft (78 hp) for a few hours of work and some factory parts that can be gleaned from a junkyard? (ok; a harness that you can buy affordably or extend yourself for a dollar in wire)
Better cams exist for sure but 78HP in an afternoon is not bad IMO if budget is a constraint.
If float is a concern, what's wrong with LS2 cam, LS2 springs and shift at 6250-ish? Gains at 5,500 are still significant: +46 lb-ft (48 hp). At 6000 we are probably up ~65HP.
Wish they were more specific about which 5.3l and which intake.
This was probably a 295hp335tq factory motor but with open headers, no intake tract, limited or no accessories etc. dyno'd 350hp/385tq.
The 78hp gain was 1000rpm past the peak of the LM7 cam so should be seen as an extension of rpm capability rather than a real HP gain.
If you look at the peaks of 353 at 5200 vs. 403 at 6100 and then at the 6200rpm change you see the LM7 is dropping power HARD like 25hp loss from 6100-6200 which is about unbelievable even if it is 1000rpm past peak.
Charts would have been great.
This was probably a 295hp335tq factory motor but with open headers, no intake tract, limited or no accessories etc. dyno'd 350hp/385tq.
The 78hp gain was 1000rpm past the peak of the LM7 cam so should be seen as an extension of rpm capability rather than a real HP gain.
If you look at the peaks of 353 at 5200 vs. 403 at 6100 and then at the 6200rpm change you see the LM7 is dropping power HARD like 25hp loss from 6100-6200 which is about unbelievable even if it is 1000rpm past peak.
Charts would have been great.
You guys are correct.. Crank numbers are different, and obviously this is not a completely stock engine either. You have to take the numbers with a grain of salt but even if you ignore the actual HP numbers, look at % difference. No matter how "out of whack" the setup is, all cams were tested on same out of whack setup and gains were made.
It makes a case for trying out stock cams when budget is #1 priority and that's all that was indicated.
It occurs to me that LS1 or LS2 cam would make that engine behave more like a car engine vs. a truck engine and I gathered that's what OP was trying to do without spending $$. My budget changed before I got my 5.3 together and I am on a very different path now. Only reason I'm not running a 5.3/LS1 cam right now.
+1 Charts would have been great.
It makes a case for trying out stock cams when budget is #1 priority and that's all that was indicated.
It occurs to me that LS1 or LS2 cam would make that engine behave more like a car engine vs. a truck engine and I gathered that's what OP was trying to do without spending $$. My budget changed before I got my 5.3 together and I am on a very different path now. Only reason I'm not running a 5.3/LS1 cam right now.
+1 Charts would have been great.
Last edited by Mercier; Jan 28, 2015 at 08:18 PM.
