6.0 LS3 heads, Considering new truck cam, suggestions?
02-16-2019, 01:35 PM
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6.0 LS3 heads, Considering new truck cam, suggestions? okay heres what i have
2000 LQ4 stock bottom end
cam is custom grind 218/226 .563"/.570" 110LSA +4 advance [ comp XE lobes]
stock ls3 heads PAC 1518 springs
L92 intake
dual 2.5" exhaust ls2 manifolds.
stock stall 4L80E
tuned to run on 91 octane
this is in a 6000lb 1 ton 4x4 truck, i daily drove it for 2 years on 91 octane and spent a fortune in gas. drove about 20,000km [12.5k miles]
the lifters are shot and i have to dig back into it, moving forward what i would like to do is dial it back a little bit and run 87 octane, potentially with a smaller cam. i also have longtube headers i am going to install at the same time.
i have been reading and it seems like the 212/218 low lift cam is a favorite amongst many. my goals for the future are to save a couple bucks on fuel and make it a better runner all year long and loose some of the lump in the cam. most of my power with this setup seems to be in the mid range, it seems to lack power above 5000rpm, and its not insanely torquey from a light. id like to have lots of low end torque and good mid range.
i understand that for low end torque cathedral port heads may be a better choice and the ls3s are better for high rpm, but i already own em so thats what im gonna run... again.
opinions welcome
thx
2000 LQ4 stock bottom end
cam is custom grind 218/226 .563"/.570" 110LSA +4 advance [ comp XE lobes]
stock ls3 heads PAC 1518 springs
L92 intake
dual 2.5" exhaust ls2 manifolds.
stock stall 4L80E
tuned to run on 91 octane
this is in a 6000lb 1 ton 4x4 truck, i daily drove it for 2 years on 91 octane and spent a fortune in gas. drove about 20,000km [12.5k miles]
the lifters are shot and i have to dig back into it, moving forward what i would like to do is dial it back a little bit and run 87 octane, potentially with a smaller cam. i also have longtube headers i am going to install at the same time.
i have been reading and it seems like the 212/218 low lift cam is a favorite amongst many. my goals for the future are to save a couple bucks on fuel and make it a better runner all year long and loose some of the lump in the cam. most of my power with this setup seems to be in the mid range, it seems to lack power above 5000rpm, and its not insanely torquey from a light. id like to have lots of low end torque and good mid range.
i understand that for low end torque cathedral port heads may be a better choice and the ls3s are better for high rpm, but i already own em so thats what im gonna run... again.
opinions welcome
thx
02-16-2019, 01:40 PM
#2
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Look into Cam Motion's mild LS3 cams. They have a 212/222, .553/.553, 116LSA that might help you. It has more exhaust duration that LS3 heads like, plus it's advanced 3 degrees for good bottom end torque.
02-19-2019, 02:55 PM
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We have the SUM-8712 209/217 112 + 1 (.500 lift drop-in) and the SUM-8719 (.550 lift version) Pro LS Truck cams available as well. Actually we have another one specifically for towing/RV use called the SUM-8718 205/217 112+2 .500 lift as well. We changed the intake events up a little more on that one for more off-idle torque.
One thing to note is most times when you go with a smaller cam, it closes the intake valve sooner and will build compression down low. If you're on the edge of knock already from timing, this could be a step backwards. Do you have a colder thermostat in it? Have you heard or logged knock or is that just what the tuner indicated he would set timing at when he did it. Knock with a LQ4 wouldn't be very common normally due to the compression.
One thing to note is most times when you go with a smaller cam, it closes the intake valve sooner and will build compression down low. If you're on the edge of knock already from timing, this could be a step backwards. Do you have a colder thermostat in it? Have you heard or logged knock or is that just what the tuner indicated he would set timing at when he did it. Knock with a LQ4 wouldn't be very common normally due to the compression.
Last edited by Summitracing; 02-19-2019 at 03:00 PM.
02-19-2019, 03:42 PM
#5
One benefit of running 91 over 87 is running higher timing and or compression and that will get you higher MPG.
Om my 04 5.3 I did a 93 tune and gained 2 mpg, it pretty much washed out the additional cost of the higher octane. You also leave some power on the table with 87
Om my 04 5.3 I did a 93 tune and gained 2 mpg, it pretty much washed out the additional cost of the higher octane. You also leave some power on the table with 87
02-19-2019, 09:32 PM
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Hey Summit!! Any dyno graphs available for the 8718 and 8719 vs a stock lq9 cammed 6.0? I'm on the fence between the two and ready to buy right now 
Particularly interested in gains over the lq9/ls1 cam in the 2500-6000 rpm range.
Particularly interested in gains over the lq9/ls1 cam in the 2500-6000 rpm range. Trending Topics
02-20-2019, 09:06 AM
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The LQ9/LS1 intake opens at 17 after tdc and closes at 33 degrees after bdc. The exhaust opens at 37 bbdc and closes about 16 btdc.
SUM-8718 opens at 8 after tdc and closes at 33 bdc. Surprise Surprise! Our exhaust opens at 42 btdc and closes at 5 btdc
To get more air in on the intake stroke, the added duration is all on the opening side. This is about as early as we want to go with without getting pulling dirty air in from overlap. One goal was to maintain (if not increase) gas mileage. The exhaust side opens a bit earlier there and we close quite a bit later at 5 btdc. The ramps are a fair amount quicker and we hold lift to .500 on that particular cam to work with factory springs to get more air in even yet.
Next up, it has similar duration to the LS6 cam at 204/218. That cam though has 117 degrees of lobe separation and it's installed 4 degrees retarded. Numbers become I/O -19, I/C 43, E/O 42, E/C -4. So we're using about the same exhaust timing as the LS6 cam. Our intake events by themselves are advanced about 10 degrees on both sides though to build torque.
02-20-2019, 09:58 AM
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Hey Summit, I actually meant it as a compliment I think it's great yall are trying to make some real usable low rpm power. I'm on the fence with your 8718 and 8719 for my 6.0 z71. Can you clarify the differences in performance between the two please? Maybe a dyno graph or two? Thanks a million!!!!
I think it's great yall are trying to make some real usable low rpm power. I'm on the fence with your 8718 and 8719 for my 6.0 z71. Can you clarify the differences in performance between the two please? Maybe a dyno graph or two? Thanks a million!!!!
02-20-2019, 10:35 AM
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Yes and we took it that way too lol. How we targeted valve events was a fun exercise and we did look at the factory cams a lot in the process. We haven't had a lot of people post dyno graphs yet.
The SUM-8719 is probably my favorite of the two unless towing/RV is about all you do with the truck. Coming out of a 218 cam with 110 Lobe separation, we understand where you're coming from...but you're still going to want "some" cam to it and the SUM-8719 will allow you to set your lope with idle rpm. The SUM-8718 is pretty docile if not almost invisible even at 600 rpm.
The SUM-8719 is probably my favorite of the two unless towing/RV is about all you do with the truck. Coming out of a 218 cam with 110 Lobe separation, we understand where you're coming from...but you're still going to want "some" cam to it and the SUM-8719 will allow you to set your lope with idle rpm. The SUM-8718 is pretty docile if not almost invisible even at 600 rpm.
02-21-2019, 09:32 PM
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wow, lots of action here thats great! thanks Summit for providing some options and your 2 cents.
im not certain if my current setup would be okay with anything other than 91 octane, thats just what i was tuned on from the begining. it would be a good idea to pump some 87 and log for knock but i dont really have that option now, the lifters are so badly collapsed that it backfires like crazy and barely runs in this cold.
what are people using for lifters now, i see theres 2 Chevrolet performance lifter kits the 12499225 and the more expensive 12595365.
im not certain if my current setup would be okay with anything other than 91 octane, thats just what i was tuned on from the begining. it would be a good idea to pump some 87 and log for knock but i dont really have that option now, the lifters are so badly collapsed that it backfires like crazy and barely runs in this cold.
what are people using for lifters now, i see theres 2 Chevrolet performance lifter kits the 12499225 and the more expensive 12595365.
02-21-2019, 11:11 PM
#17
I used the 8718 cam from summit in my lq4 build for my truck that I daily drive. It’s a half ton with 3:42 gears so low end grunt was important to me while still maintaining good mileage while towing. I’ve got a couple thousand miles on my engine now and I can say that this cam was well thought out. The low and mid range torque is impressive while still being able to pull up top a bit. I’m currently running a flex tune and content sensor and gains are maximized with running e85 if that is an option for you. On pump gas it will chop slightly when warm with the idle set at 585 in park. For whatever reason there is no chop at an idle above 30 percent ethanol content. A bit long winded but just my experience with one of the summit truck cams. I would recommend and purchase again. Also used the summit ls7 style lifters and trays for around 150 bucks. They are quiet during cold start and when warm as well running mobile 5w30. Seem like high quality lifters
Last edited by andy burdess; 02-21-2019 at 11:17 PM.
02-22-2019, 09:13 AM
#18
I have the Cam Motion 206/216 .553/.553 117+4 in my 6000lb Avalanche and it runs great...(LS3 Swap)
http://www.cammotion.com/camshafts/6...206-216-117-4/
http://www.cammotion.com/camshafts/6...206-216-117-4/
02-22-2019, 01:46 PM
#19
People absolutely love our truck cams. Here is a link to a fellow LS1Tech member's results:
https://ls1tech.com/forums/dynamomet...hp-22rwtq.html
Get free shipping by using the coupon code: Cam Motion USA.
https://ls1tech.com/forums/dynamomet...hp-22rwtq.html
Get free shipping by using the coupon code: Cam Motion USA.
02-26-2019, 09:36 AM
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hey Cam Motion! do you have a suggestion on which of your truck cams youd choose for a LS3 headed stock 6.0L in a heavy truck [stock converter]?
truck sees limited use now, occasionally tows, 90% highway driving on asphalt %10 pulling out stuck friends, and off-roading.
ive lost my taste for lumpy idles, don't care what it sounds like now as long as there is lots of low and midrange torque.
truck sees limited use now, occasionally tows, 90% highway driving on asphalt %10 pulling out stuck friends, and off-roading.
ive lost my taste for lumpy idles, don't care what it sounds like now as long as there is lots of low and midrange torque.