Advancing a LS6 cam in a 5.3 Silverado
08-26-2013, 10:48 AM
#41
It's up on jackstands right now, putting poly bushings in the leafs, forgot how much fun it was, but will be back on it this week.
08-26-2013, 01:34 PM
#43
I have not straight out seen "DON'T DO THIS".. but considering the tach on the silverado this came out of only goes to 6k, the stock redline in the program is 5600...
I've heard the rod bolts are the weak link in these engines and I don't have the money to buy another block, so I'm taking the safe path.
I've heard the rod bolts are the weak link in these engines and I don't have the money to buy another block, so I'm taking the safe path.
08-26-2013, 01:49 PM
#44
Thats not because of the rod bolts, its more for the powerband of the engine. Truck engines suck ***** up that high anyways due to the cam/intake.
The rod bolts are fine to 6500, and some spin to 7k.
The rod bolts are fine to 6500, and some spin to 7k.
10-14-2013, 07:40 AM
#45
Seeing if anyone else has updates.
Since last post I've done this:
It pulled flawlessly. Needless to say I wish I had a lot more bottom end to get it up to speed, but it did do a lot better than I anticipated.
Then I found that I had knocked the vacuum hose loose @ the reservoir and been running / tuning it ever since. This is w/ the vac line plugged in, haven't gone back in to adjust the tune, need to pull a lot of fuel out @ low rpms:
https://docs.google.com/file/d/0B8kv...it?usp=sharing
Talked with an engineer @ work. He has a custom cam software setup and he is VERY detail oriented. He looked @ the stock L33 cam vs LS6 cam. Said the cam needs to be advanced 2 degrees as it has a lot of cylinder bleed out @ low rpms. Something we've all agreed upon. He said the LS6 has higher compression to deal with this but the 9.9 CR in the L33 wouldn't quite work as well.
I'm saving up for a adjustable timing setup, just have to somehow figure out it piston to valve clearance will be an issue.. Would love to figure it out w/o pulling the heads as I don't want to put another $100 in gaskets / tty bolts.
Since last post I've done this:
It pulled flawlessly. Needless to say I wish I had a lot more bottom end to get it up to speed, but it did do a lot better than I anticipated.
Then I found that I had knocked the vacuum hose loose @ the reservoir and been running / tuning it ever since. This is w/ the vac line plugged in, haven't gone back in to adjust the tune, need to pull a lot of fuel out @ low rpms:
https://docs.google.com/file/d/0B8kv...it?usp=sharing
Talked with an engineer @ work. He has a custom cam software setup and he is VERY detail oriented. He looked @ the stock L33 cam vs LS6 cam. Said the cam needs to be advanced 2 degrees as it has a lot of cylinder bleed out @ low rpms. Something we've all agreed upon. He said the LS6 has higher compression to deal with this but the 9.9 CR in the L33 wouldn't quite work as well.
I'm saving up for a adjustable timing setup, just have to somehow figure out it piston to valve clearance will be an issue.. Would love to figure it out w/o pulling the heads as I don't want to put another $100 in gaskets / tty bolts.
10-14-2013, 09:21 AM
#46
Seeing if anyone else has updates.
Since last post I've done this:
It pulled flawlessly. Needless to say I wish I had a lot more bottom end to get it up to speed, but it did do a lot better than I anticipated.
Then I found that I had knocked the vacuum hose loose @ the reservoir and been running / tuning it ever since. This is w/ the vac line plugged in, haven't gone back in to adjust the tune, need to pull a lot of fuel out @ low rpms:
https://docs.google.com/file/d/0B8kv...it?usp=sharing
Talked with an engineer @ work. He has a custom cam software setup and he is VERY detail oriented. He looked @ the stock L33 cam vs LS6 cam. Said the cam needs to be advanced 2 degrees as it has a lot of cylinder bleed out @ low rpms. Something we've all agreed upon. He said the LS6 has higher compression to deal with this but the 9.9 CR in the L33 wouldn't quite work as well.
I'm saving up for a adjustable timing setup, just have to somehow figure out it piston to valve clearance will be an issue.. Would love to figure it out w/o pulling the heads as I don't want to put another $100 in gaskets / tty bolts.
Since last post I've done this:
It pulled flawlessly. Needless to say I wish I had a lot more bottom end to get it up to speed, but it did do a lot better than I anticipated.
Then I found that I had knocked the vacuum hose loose @ the reservoir and been running / tuning it ever since. This is w/ the vac line plugged in, haven't gone back in to adjust the tune, need to pull a lot of fuel out @ low rpms:
https://docs.google.com/file/d/0B8kv...it?usp=sharing
Talked with an engineer @ work. He has a custom cam software setup and he is VERY detail oriented. He looked @ the stock L33 cam vs LS6 cam. Said the cam needs to be advanced 2 degrees as it has a lot of cylinder bleed out @ low rpms. Something we've all agreed upon. He said the LS6 has higher compression to deal with this but the 9.9 CR in the L33 wouldn't quite work as well.
I'm saving up for a adjustable timing setup, just have to somehow figure out it piston to valve clearance will be an issue.. Would love to figure it out w/o pulling the heads as I don't want to put another $100 in gaskets / tty bolts.
Did my tune help any?
I would take the time to do some logs and modify the tune for sure ASAP.
Looks like it runs MUCH better, I knew something was wrong.
People say a LS6 cam is "dead" at lower rpms, mines make 300ft lbs of tq at 2200 rpms in my LS6
10-14-2013, 10:23 AM
#47
I decided to leave my truck alone.
Did my tune help any?
I would take the time to do some logs and modify the tune for sure ASAP.
Looks like it runs MUCH better, I knew something was wrong.
People say a LS6 cam is "dead" at lower rpms, mines make 300ft lbs of tq at 2200 rpms in my LS6
Did my tune help any?
I would take the time to do some logs and modify the tune for sure ASAP.
Looks like it runs MUCH better, I knew something was wrong.
People say a LS6 cam is "dead" at lower rpms, mines make 300ft lbs of tq at 2200 rpms in my LS6
I'll be throwing 93 in there soon and go for max tuning. I am running datalogs everytime I turn the key and am updating the tune, having to pull a lot of fuel out down low.Your LS6 has 10.5:1 compression, my L33 has 9.9:1, so it does run differently in my setup. It still doesn't have any azz off the line. I can nail it from a dead stop and it doesn't break loose, but I'm sure it's due to the weight over the rear axle and the sticky 275/40s I'm running.
10-14-2013, 01:25 PM
#48
It did, thank you for sending it! I'm not running the same timing curve as you due to I'm still running 87 octane. Datalogging I'm running 14-18 degrees @ wot. Trying to keep it somewhat cheaper to drive. I'll be throwing 93 in there soon and go for max tuning. I am running datalogs everytime I turn the key and am updating the tune, having to pull a lot of fuel out down low.
Your LS6 has 10.5:1 compression, my L33 has 9.9:1, so it does run differently in my setup. It still doesn't have any azz off the line. I can nail it from a dead stop and it doesn't break loose, but I'm sure it's due to the weight over the rear axle and the sticky 275/40s I'm running.
I'll be throwing 93 in there soon and go for max tuning. I am running datalogs everytime I turn the key and am updating the tune, having to pull a lot of fuel out down low.Your LS6 has 10.5:1 compression, my L33 has 9.9:1, so it does run differently in my setup. It still doesn't have any azz off the line. I can nail it from a dead stop and it doesn't break loose, but I'm sure it's due to the weight over the rear axle and the sticky 275/40s I'm running.
Glad I could help.
11-06-2013, 11:53 PM
#49
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Back to the original testimony at hand:
Has anyone advanced the ls6 cam from 120 ICL back to at least 116?
I've got a 243 headed lq4 ( basicslly lq9) in a 94 RCSB with 285's and 3.42's. I'd love to give it something that doesn't kill the bottom end power. I know I'm already doing better than the OP by having a 6.0, but having something I can build power to up around 6k would be nice.
Has anyone advanced the ls6 cam from 120 ICL back to at least 116?
I've got a 243 headed lq4 ( basicslly lq9) in a 94 RCSB with 285's and 3.42's. I'd love to give it something that doesn't kill the bottom end power. I know I'm already doing better than the OP by having a 6.0, but having something I can build power to up around 6k would be nice.
11-07-2013, 09:31 PM
#50
The 5.3 on the other hand shares it's overall design with the ls1. With the exception of the intake, it's basically a smaller ls1. And the ls1 was designed to rev, and naturally, the 5.3 will have to be wound out to make power as well.
If there was an ls head designed with a swirl ramp like the tbi heads and a matching cam, it would make a ton of power down low and be done by 5k. It would truly be the ultimate towing engine giving great mileage and great power.
03-31-2017, 09:39 AM
#51
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Just wanted to add this link and info to the discussion for future readers/ searches. Everyone who said the LS6 cam just isn't right for low end torque production was right, totally different personality. (I was liking the OP's thought process initially)
See this test that someone already mentioned, which is awesome that Hot Rod/Car Craft put the work into this so we really know.
http://www.hotrod.com/articles/ls-cam-test-comparison/
It appears the best cam options for 5.3L low end torque are:
1. stock LM7 cam. Adding 1.8 rockers could be the perfect addition (NO CAM SWAP)
2. LQ9 / 01-02 LS1 cam could be very good, very affordable, advancing the cam 4 deg could negate slight low end torque loss, while still adding 20-30 HP at 6,000rpm. (Lift .479/.467 duration 207/196 LSA 116 )
3.Crane 200 as tested in article, (Lift .502/.502 duration 200/200 LSA 113)
4. LS2 cam is also a great cam for way more top end, without hurting the bottom end too much, and could be advanced 4 deg
See this test that someone already mentioned, which is awesome that Hot Rod/Car Craft put the work into this so we really know.
http://www.hotrod.com/articles/ls-cam-test-comparison/
It appears the best cam options for 5.3L low end torque are:
1. stock LM7 cam. Adding 1.8 rockers could be the perfect addition (NO CAM SWAP)
2. LQ9 / 01-02 LS1 cam could be very good, very affordable, advancing the cam 4 deg could negate slight low end torque loss, while still adding 20-30 HP at 6,000rpm. (Lift .479/.467 duration 207/196 LSA 116 )
3.Crane 200 as tested in article, (Lift .502/.502 duration 200/200 LSA 113)
4. LS2 cam is also a great cam for way more top end, without hurting the bottom end too much, and could be advanced 4 deg
Last edited by Flatblak; 03-31-2017 at 10:04 AM.
