LS1 cam in 5.3L LM7
#22
Thats the same cam (same as LQ4, LQ9) that came in the GM 5.3 HO package:
http://www.jrgmparts.com/GM_Performa...h_output_.html
Anyone know anything more about this? The HO dyno chart from GM claims 332 horsepower and 352 lb.-ft with the cam and piston coatings as the only updates...
http://www.jrgmparts.com/GM_Performa...h_output_.html
Anyone know anything more about this? The HO dyno chart from GM claims 332 horsepower and 352 lb.-ft with the cam and piston coatings as the only updates...
#23
TECH Enthusiast
iTrader: (4)
Thats the same cam (same as LQ4, LQ9) that came in the GM 5.3 HO package:
http://www.jrgmparts.com/GM_Performa...h_output_.html
Anyone know anything more about this? The HO dyno chart from GM claims 332 horsepower and 352 lb.-ft with the cam and piston coatings as the only updates...
http://www.jrgmparts.com/GM_Performa...h_output_.html
Anyone know anything more about this? The HO dyno chart from GM claims 332 horsepower and 352 lb.-ft with the cam and piston coatings as the only updates...
The 1721 cam is an upgrade from the LM7 cam, in some ways. It would be helpful with boost.
When you take a great overall vehicle combination, and change the exhaust opening to be earlier, you will feel a loss of low-rpm torque. This is a large part of what you get if you swap the LM7 cam for the 1721 cam.
Swapping the '02-'04 LS6 cam is the same thing only worse. The torque loss is dramatic, 22 ft-lbs at 2500 rpm, and not even equal until after 3800 rpm. And you have to get past 4700 rpm to be up those same 22 ft-lbs. That's really a bad trade for the street. How much of your driving is done above 3800 rpm? 1%? 5%?
#25
TECH Senior Member
It would work well, as there is enough difference in the specs that you will notice some increase in power. It's the same cam as the LQ9 6.0. It's a good swap!
#27
TECH Veteran
iTrader: (40)
In a heavy car, I wouldn't do it. A lot of people with trucks have swapped in LS1/6 cams and hated them. I haven't heard a person yet say that they liked a stock LS cam in a 5.3. If you do a converter and the car isn't too heavy it wouldn't be bad. Under 3500 pounds or so should be good. Over 4k I'd look at a cam made for more low end.
#28
Do it! My intial setup when I first swapped my car was an Lm7 with an 02 ls1 cam, stock 706 heads with an ls6 intake, ls1 throttle body and f body exhaust manifolds. Car made 308rwhp and 323rwtq on a dynojet. Not sure what it would of made with the stock truck cam, but for a motor that was rated at 285-290 at the crank, it did pretty damn good. Driveability was perfect and she hauled ***.
#30
TECH Senior Member
In a heavy car, I wouldn't do it. A lot of people with trucks have swapped in LS1/6 cams and hated them. I haven't heard a person yet say that they liked a stock LS cam in a 5.3. If you do a converter and the car isn't too heavy it wouldn't be bad. Under 3500 pounds or so should be good. Over 4k I'd look at a cam made for more low end.
#31
The late LS6 cam is bad news for a 5.3. The early one, however proved to increase power from fairly early on and really gave the 5.3 a nice boost. This grind is the same as the LS2. The late LS1 Cam (same as the LQ9) was also good for the 5.3 though not as powerful as the early LS6. ALL this was from a test done by Hot Rod Magazine some years back.
#33
TECH Senior Member
LM7, LR4, LQ4- 191/190deg., .466/.457, 114LSA
LQ9, late LS1 -- 196/201deg., .467/.479, 116LSA
Early LS1------- 202/210deg., .496/.496, 116LSA
Early LS6, LS2 - 204/211deg., .525/.525, 116LSA
Late LS6 ------- 204/218deg., .551/.547, 116LSA
Note- These are all Gen III cams.
Last edited by G Atsma; 02-06-2021 at 10:51 AM.
#34
TECH Addict
https://www.hotrod.com/articles/ls-cam-test-comparison/ It looks the best overall stock cam for the LM7 is the LS2 cam. Very little loss in torque and good power up top you just need better springs.
#35
TECH Senior Member
https://www.hotrod.com/articles/ls-cam-test-comparison/ It looks the best overall stock cam for the LM7 is the LS2 cam. Very little loss in torque and good power up top you just need better springs.
#36
TECH Veteran
iTrader: (40)
The late LS6 cam is bad news for a 5.3. The early one, however proved to increase power from fairly early on and really gave the 5.3 a nice boost. This grind is the same as the LS2. The late LS1 Cam (same as the LQ9) was also good for the 5.3 though not as powerful as the early LS6. ALL this was from a test done by Hot Rod Magazine some years back.
The smaller motors perform best with tight LSA, all the stock cams have a wide LSA. Look at the posts from 5.3LJimmy in here, he's actually tried it and tested it, didn't work. Also check with Joe Nova, he's posted some dyno charts of essentially the same cams in a 5.3 but with different LSA's. The tight LSA cams work far better.
I posted what I did after reading a lot on performancetrucks.net, where a huge percentage of the people have 5.3's, haven't seen anyone yet say they liked a stock LS1/6 cam in a 5.3.
Most of the complaint is going to come from under the curve driving (part throttle & lower rpm). The hot rod test shows WOT only, and it doesn't show you what's going on at 1000-2500 either where most of the driving will be done. Those little motors need all the help they can get, it doesn't take much of a cam change to make a big difference in a bad way.
That's why I said if it's going in a light car.. cool, and if a stall converter will be used that'll help. But in a heavy car with a stock stall it's gonna be a dog.
#37
Have a look at the part number on the front of the stock LS1 camshaft and cross reference it with the camshaft tech post on here to find the actual specs. That will give you a better idea of the actual difference between it & your 5.3 cam.
You can then decide whether it's worth looking for something a bit more interesting or not.
You can then decide whether it's worth looking for something a bit more interesting or not.
#38
TECH Senior Member
The smaller motors perform best with tight LSA, all the stock cams have a wide LSA. Look at the posts from 5.3LJimmy in here, he's actually tried it and tested it, didn't work. Also check with Joe Nova, he's posted some dyno charts of essentially the same cams in a 5.3 but with different LSA's. The tight LSA cams work far better.
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BTR's Truck Torque cam is a case in point. 202/202, .511/.511, 111+1.
Gained 20# torque throughout the RPM scale!
Plus, it shows mild engines like single-pattern cams, besides narrow LSA's
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#39
TECH Senior Member
#40
Texas speed stage 2 truck cam the little cam that could
Dyno sheet car makes 330 tq at 1500 rpm and by 2500 rpm all 350 tq from there on up
Last edited by UtahBlueDrean; 03-23-2021 at 10:12 PM. Reason: Pictures added of dyno sheet
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G Atsma (03-26-2021)