Built ls3 with mods, low torque numbers
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From: Central Cal.
Pooter, good catch on the bore spec! I had to look up the LS3 bore spec, and it's bigger than what he said he bored to! lol
I bet he has an LQ4 or LQ9 block being it's cast iron, which I caught from the first post.
Also seen from the first post, he says it has only top end power, which indicates to me a retarded cam.
I remember my '78 Ford E-250 van with 460 had the factory retarded cam and it couldn't get out of its own way. It ran out of breath before the cam had anything to say...
I bet he has an LQ4 or LQ9 block being it's cast iron, which I caught from the first post.
Also seen from the first post, he says it has only top end power, which indicates to me a retarded cam.
I remember my '78 Ford E-250 van with 460 had the factory retarded cam and it couldn't get out of its own way. It ran out of breath before the cam had anything to say...
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Pooter, good catch on the bore spec! I had to look up the LS3 bore spec, and it's bigger than what he said he bored to! lol
I bet he has an LQ4 or LQ9 block being it's cast iron, which I caught from the first post.
Also seen from the first post, he says it has only top end power, which indicates to me a retarded cam.
I remember my '78 Ford E-250 van with 460 had the factory retarded cam and it couldn't get out of its own way. It ran out of breath before the cam had anything to say...
I bet he has an LQ4 or LQ9 block being it's cast iron, which I caught from the first post.
Also seen from the first post, he says it has only top end power, which indicates to me a retarded cam.
I remember my '78 Ford E-250 van with 460 had the factory retarded cam and it couldn't get out of its own way. It ran out of breath before the cam had anything to say...
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
You mentioned in your first post a cast iron 6.2 block. That does not exist in stock form, which is what confused some of us. So you have a 6.0 block, which as you NOW say is a LQ4/LQ9 block.
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Sorry for confusion. Block is 6.0 liter LQ4, bored to 4.030, so it is not 6.0 anymore. donor engine itself came from Hummer H2. But I mentioned in the first post that the block was cast iron, so I assumed that it came from LQ4/9 engine
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I have ordered camshaft timing kit from Comp Cam, once it will arrive I will try to retard the camshaft. Why retard? my camshaft is 281lrr hr-13, LSA is 113, intake lobe centerline is 109, so this camshaft is factory advanced by 4 degrees. what do you think, am I at the right way?
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I have ordered camshaft timing kit from Comp Cam, once it will arrive I will try to retard the camshaft. Why retard? my camshaft is 281lrr hr-13, LSA is 113, intake lobe centerline is 109, so this camshaft is factory advanced by 4 degrees. what do you think, am I at the right way?
The red headers can only be two things...retarded timing, or a lean fuel condition. Your ignition timing sounds good (assuming it’s correct), maybe a tad much, as said earlier.
Do you know what your AFR readings were?
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Ok, you’ve gotten good advice a couple times already, but I’ll say it again...you need to put a degree wheel on the crankshaft, and check the cam timing. Make sure your camshaft was ground correctly before you change anything.
The red headers can only be two things...retarded timing, or a lean fuel condition. Your ignition timing sounds good (assuming it’s correct), maybe a tad much, as said earlier.
Do you know what your AFR readings were?
Last edited by Goga Samsonadze; Aug 12, 2018 at 03:44 PM.
Most tuners shoot for 14.7 to 15 at idle. Optimum performance ratio at WOT is 12.7, as a general rule of thumb.
Sounds to me like you need fuel, and fuel equals power, but I don’t understand the “average” term you used. Would definately explain the red headers however.
Sounds to me like you need fuel, and fuel equals power, but I don’t understand the “average” term you used. Would definately explain the red headers however.
Last edited by Che70velle; Aug 12, 2018 at 07:17 PM. Reason: spellcheck...
I have ordered camshaft timing kit from Comp Cam, once it will arrive I will try to retard the camshaft. Why retard? my camshaft is 281lrr hr-13, LSA is 113, intake lobe centerline is 109, so this camshaft is factory advanced by 4 degrees. what do you think, am I at the right way?
Ok, you’ve gotten good advice a couple times already, but I’ll say it again...you need to put a degree wheel on the crankshaft, and check the cam timing. Make sure your camshaft was ground correctly before you change anything.
The red headers can only be two things...retarded timing, or a lean fuel condition. Your ignition timing sounds good (assuming it’s correct), maybe a tad much, as said earlier.
Do you know what your AFR readings were?
I give up.
I do not think messing with your cam is the answer here unless you replace it with a smaller cam. The cam needs compression as stated above. Advancing the cam will get you back some dynamic compression, but will open exhaust earlier. Regarding the cam will give up more torque with no benefit.
Red headers tends to be low idle spark, like under 15 degrees. LS likes 18+ degrees at idle. Other cause is lean condition at idle or both. This can fool you because some cams like to idle lean. But it is actually false lean due to overlap. Keep running it, eventually your oxygen sensor will overheat, ignite, burn up your harness, and your low torque issue will be long forgotten. Or solved. Depending on your point of view. I doubt only one primary is glowing. More likely the wrap is hiding it. Take the wrap off I bet your headers are a really cool looking purple.
You do not need expensive pistons to gain compression. Just mill the heads and go to a thinner HG. But honestly, I think your cam is just too big. If you post a tune file we can look. I will reserve judgement until then.
Red headers tends to be low idle spark, like under 15 degrees. LS likes 18+ degrees at idle. Other cause is lean condition at idle or both. This can fool you because some cams like to idle lean. But it is actually false lean due to overlap. Keep running it, eventually your oxygen sensor will overheat, ignite, burn up your harness, and your low torque issue will be long forgotten. Or solved. Depending on your point of view. I doubt only one primary is glowing. More likely the wrap is hiding it. Take the wrap off I bet your headers are a really cool looking purple.
You do not need expensive pistons to gain compression. Just mill the heads and go to a thinner HG. But honestly, I think your cam is just too big. If you post a tune file we can look. I will reserve judgement until then.
