5.3L LM7 Build Questions
#1
5.3L LM7 Build Questions
I just brought home a LM7 motor out of a 2002 chevy suburban from a local junkyard and plan on doing some budget performance mods. I plan on replacing the cam with something from one of the LS series motors, not sure wich one, possible the ZO6 cam? I was also wondering what the maximum lift i could run with a cam on stock rockers and valve springs? Furthermore i was looking into doing a port and polish job on the heads myself, just an idea, but do you think i will gain any power doing it myself? Any other good performance ideas on a budget would help. Thanks
#2
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I think the Z06 cam is more for a supercharged or turbocharged app. I have a 220R in my 5.3 truck with a 3600 stall and i love it. Other good cams would be a 222/224 or a 224R
#3
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I dont think you'll notice much of a difference with a Z06 cam. Get a smaller aftermarket cam. your stock rockers will be fine, but definately upgrade springs and pushrods. The stock springs are barely good enough for a stock cam.
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The only stock cam I would consider is the 02 Z06 cam. But I would highly recommend you use something from the aftermarket. There are plenty of used cams for sale for a good price that will be much better. Alot of entry level sized cams for the LS1 have very good results in the 5.3, and since most here start with a smaller cam and then upgrade to larger they are plentiful.
You can buy a set of LS6 springs from Scoggin Dickey for around $70 which are good to .570 lift. I would not run any cam other than stock on the stock springs.
You can buy a set of LS6 springs from Scoggin Dickey for around $70 which are good to .570 lift. I would not run any cam other than stock on the stock springs.
#6
Alright so ill be looking for a used aftermarket cam, any recomendations on lift and duration? I was also wondering what the LSA ment in refrence to cam specs. Thanks Im kinda new to this stuff
#7
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For a 5.3 you will be looking for something with a duration of 224/224 or less. Larger cams than this start to kill the bottom end torque. Lobe seperation angle(LSA) determines valve overlap. The tighter the LSA the more lope the cam will have, and the peak power will be moved down in the RPM range.
There is a lot of good information in the stickies at the top of the internal engine page. Reading that will answer alot of your general questions. If you go to the performance trucks site(by clicking the tab all the way at the top of this page) you will find more info and results from people running the 5.3L's.
There is a lot of good information in the stickies at the top of the internal engine page. Reading that will answer alot of your general questions. If you go to the performance trucks site(by clicking the tab all the way at the top of this page) you will find more info and results from people running the 5.3L's.
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#8
I talked to my local engine builder and i can get an stock LS1 cam for 80$ which should have 197/207 @ .05 and 467/479 lift with a 16 LSA I could also get a LQ9 cam with 207/196 and .479/.467 16 LSA for even cheaper. I dont want to move my HP too far up in the RPMs with the greater LSA but the price sounds pretty good to me.. any opinions
#9
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I have the stock LS1 cam in my '01 5.3L chevy truck. It has less bottom end than the stocker and doesn't seem to do any better on top till about 5000RPM's. I swapped it as an experiment just to see if the added duration would overcome the wider LSA. I can assure you it does not. That's why I feel the stock LS6 cam is not the best choice. Something with similar duration and a narrower lobe separation would do much better.
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dont do an LS1 cam. just look around in the for sale section here and on performancetrucks.net for a good used cam for cheap. springs as well. you will be much happier with an aftermarket cam rather than one from an LS engine
the Z06 cam is more for FI applications like stated previously above. you wont see hardly any gain
just my .02
the Z06 cam is more for FI applications like stated previously above. you wont see hardly any gain
just my .02