5.3L Truck Motor Cam-only
03-15-2014, 03:19 PM
#81
Jake,
I would believe that to be so. Bore does not affect piston speed or where the highest FPS in relation to crank position occurs.
Bore does affect piston demand though. How much that piston can "pump" and how much flow it demands from the cylinder head.
Larger bore also shrouds the intake valve less. This is seen as a gain in low-mid lift flow numbers which generally translates into increased low and mid-range torque.
I would believe that to be so. Bore does not affect piston speed or where the highest FPS in relation to crank position occurs.
Bore does affect piston demand though. How much that piston can "pump" and how much flow it demands from the cylinder head.
Larger bore also shrouds the intake valve less. This is seen as a gain in low-mid lift flow numbers which generally translates into increased low and mid-range torque.
03-26-2014, 01:30 AM
#82
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While I agree with you that the piston speed is the same that really has very little to do with cam selection for the 5.3L and I'm surprised you posted it that way. Part of the issue with the 5.3L is the low compression along with the small bore. The bigger the cubic inch overall the more vacuum the piston will create on the intake stroke to pull in the air during it's intake duration. The problem isn't that the 5.3L can't handle more duration, it's that it really doesn't help much past 224 degrees unless you are talking the L33 or newer engines. I have dyno'd 5.3L's with a ton of different grinds all the way up to an MS3. My truck made 345RWHP with a 222/224 cam and yet I've only had a couple make more than 350RWHP using quite a bit bigger cams that didn't drive anywhere near as nice and required a crap load more stall speed. I'll take the drivability and better low rpm torque over a bigger dyno number anyday when it is a barely bigger number at that. One of my regular customers has an LM7 with a 233/239 Texas Speed cam that idles at 800rpm and barely makes enough vacuum to be acceptable for a street car. He first installed a 3000 stall with the thought that it would be an animal and later had to go to a 3600 stall wishing he had a 4000. The L33 responds alot better to a bigger cam because it has a bit more compression to back it up. What you're saying would be the same as saying there is no difference in which camshaft you'd use for an LQ4 and an LS2. Cubic inches and compression ratio are two big factors in camshaft selection.
03-26-2014, 08:49 AM
#83
Just because I didn't mention that doesn't mean it isn't known to me. I agree 100%. I understand the depression the piston creates on the intake stroke and how cylinder pressure affects it.
Thus the problem with the internet. It would take me days to sit here in this one thread and spell out every "rule" regarding camshaft selection.
A lot of it is implied. Some will take it as gospel 100%, and those like yourself that already know...well you already know.
My absolute favorite cam for a truck like yours is a 219/219 112. I also have a 215/215 112 that works very well. What I will normally do for a dished piston 5.3 in a truck is 219/223 and I have done up to a 223/223 with a 4000 stall.
There just really is no need for more than 224-228 degrees intake duration for a 5.3 in a truck IMO. Dished piston or flat top piston.
I have a lot of track/race only guys with junkyard 5.3's in 2800-3000 lbs. mustangs with single plane intakes running our SNS Stage 2 cam which is 227/235 110lsa. It works very well in that combination as it is race only.
We used this cam in this 5.3 because it was on the shelf and felt it would work well with boost. Customer didn't want a custom camshaft.
Combination is the final deciding factor in a camshaft selection and how the vehicle is intended to be used.
Thus the problem with the internet. It would take me days to sit here in this one thread and spell out every "rule" regarding camshaft selection.
A lot of it is implied. Some will take it as gospel 100%, and those like yourself that already know...well you already know.
My absolute favorite cam for a truck like yours is a 219/219 112. I also have a 215/215 112 that works very well. What I will normally do for a dished piston 5.3 in a truck is 219/223 and I have done up to a 223/223 with a 4000 stall.
There just really is no need for more than 224-228 degrees intake duration for a 5.3 in a truck IMO. Dished piston or flat top piston.
I have a lot of track/race only guys with junkyard 5.3's in 2800-3000 lbs. mustangs with single plane intakes running our SNS Stage 2 cam which is 227/235 110lsa. It works very well in that combination as it is race only.
We used this cam in this 5.3 because it was on the shelf and felt it would work well with boost. Customer didn't want a custom camshaft.
Combination is the final deciding factor in a camshaft selection and how the vehicle is intended to be used.
Last edited by Sales@Tick; 03-26-2014 at 09:03 AM.
04-18-2014, 07:39 PM
#86
Came up with this thread in a search for a good road race / daily cam in a 5.3.
I was intending to run a ls2 cam straight up, increase quench by using a 0.040 gasket, and shave the heads to 59cc. By the way this is a L33 engine, flat tops, 799 heads etc.
Now, after reading this, I have a feeling there are better cams more suited for the application. I do not want to make a high rpm screamer. If it pulls hard to 6k I am more than happy. Higher rpm = larger wallet to make reliable power.
I will be driving the car on the street so low end power is important to me and the road race needs low end torque and a wide powerband for the corners. I will be doing a gear swap to a 3.90 or 4.10 as well on a M6.
What would you suggest in an application as such? I also do not want crazy ramp rates where I need to replace my springs often. This is why I was planning on keeping the LS2 cam, increase my SCR to increase DCR to around 8.5ish, run yellow springs, and port the heads a tiny bit to make them flow a bit nicer.
Been looking at your street heat and torque monsterrrrrrrrrr cams but not sure where to go from there. It will be n/a no forced induction.
I was intending to run a ls2 cam straight up, increase quench by using a 0.040 gasket, and shave the heads to 59cc. By the way this is a L33 engine, flat tops, 799 heads etc.
Now, after reading this, I have a feeling there are better cams more suited for the application. I do not want to make a high rpm screamer. If it pulls hard to 6k I am more than happy. Higher rpm = larger wallet to make reliable power.
I will be driving the car on the street so low end power is important to me and the road race needs low end torque and a wide powerband for the corners. I will be doing a gear swap to a 3.90 or 4.10 as well on a M6.
What would you suggest in an application as such? I also do not want crazy ramp rates where I need to replace my springs often. This is why I was planning on keeping the LS2 cam, increase my SCR to increase DCR to around 8.5ish, run yellow springs, and port the heads a tiny bit to make them flow a bit nicer.
Been looking at your street heat and torque monsterrrrrrrrrr cams but not sure where to go from there. It will be n/a no forced induction.
Last edited by Apocolipse; 04-18-2014 at 08:00 PM.
04-20-2014, 09:31 PM
#87
All of our shelf cams IMO are a bit too large for a 5.3 engine wanting to be used in the way you're planning.
I would recommend a custom cam I do a lot for 5.3 trucks.
It is 215/215 .604/.604 112+2.
This will make great bottom end and pull great to 6000rpm. Average torque is very high with this camshaft.
I would recommend a custom cam I do a lot for 5.3 trucks.
It is 215/215 .604/.604 112+2.
This will make great bottom end and pull great to 6000rpm. Average torque is very high with this camshaft.
04-25-2014, 05:03 PM
#88
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Not to dilute this thread but to support your suggested cam choice in a 5.3 Martin, here is my recently tuned ’67 Camaro running a 5.3 with stock heads milled .040”, 220/218 .56x @114 cam, LS1 intake, and 1.75” LTs. Don’t pay attention to the numbers as they are uncorrected and on a crazy conservative dyno @ higher altitude. The car is a blast on the street with great manners.
05-03-2014, 12:10 AM
#89
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I recently put a LM7 5.3 in my 00' camaro. It came from an 02' suburban with 162k on the clock. Before i put it in i swapped all the LS stuff over including the LS1 cam and Speed Engineering LT's...It runs great...idles great and pulls real hard. Took it to the track and ran a 13.34 @ 104.78, 2.08 60ft, untuned. I figured the LS1 cam would run ok till i could get it tuned but as well as it runs i don't see the need to tune it right now when i am going to go for a custom grind from Tick anyway. Just my input. Great info in this thread...thanks Martin! Marc
05-03-2014, 08:55 PM
#90
Justin,
Any pics of the 67 Camaro?
Any pics of the 67 Camaro?
05-18-2014, 11:30 PM
#91
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Great information here!
I'm swapping my top end over to an LM7 along with my TREX v2 cam.
Running ported 241's with a fast 92.
Anxious to see the numbers. Will top it off with a 200 shot
I'm swapping my top end over to an LM7 along with my TREX v2 cam.
Running ported 241's with a fast 92.
Anxious to see the numbers. Will top it off with a 200 shot
05-27-2014, 08:03 PM
#92
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After reading this thread I would like to give a cam to someone with a 5.3 truck for testing. This would be for a daily driver with no mods. You can ad mods laters. This would be one of our drop in cams off the web site. It would be a stage 1 or 2. This will not be a high HP cam just a good driver. OK who wants to try one? Kip@cammotion.com
05-27-2014, 08:36 PM
#93
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After reading this thread I would like to give a cam to someone with a 5.3 truck for testing. This would be for a daily driver with no mods. You can ad mods laters. This would be one of our drop in cams off the web site. It would be a stage 1 or 2. This will not be a high HP cam just a good driver. OK who wants to try one? Kip@cammotion.com
05-27-2014, 09:18 PM
#94
Here is a mind boggler for Lil SS and Tigger since both think that a larger engine will peak sooner and a smaller engine will peak later with identical cam timing events all other variables being identical.
This is what I noticed and mentioned to Tooley and he disagreed. I still think that just like Bozz Hawg said that overlap can help carry power further past peak, but I still am left wondering if it actually affects where power peaks and not just before peak and after peak. I mean, I can look at this graph and say, "The only different variables in this equation are a 10cc difference in port volume(from my experience not near enough to change power peak, but it's possible) and 2 degrees of overlap." That still isn't a firm enough stance for me. I'd need to see at least 4-5 more engines with these two cams in them with every other variable being the same as it was in this case to draw a conclusion. It took at least 7-8 5.3 cams for me to realize and ask myself..."Why are these 5.3's peaking so early with these cams?" So I asked an esteemed colleague of mine what he thought and his advice was, "Cam the 5.3 with the same IVC as a 5.7/6.0 and watch what happens." So I did and saw that for the same IVC event as I was using in the larger bore engines, once used in a 5.3 engine with a smaller bore, it produced the same peak power rpm as the larger bore engine did.
LS1(3.898" x 3.622") with the 239/244 112+3 V.2 Polluter. Events are:
10.5 IVO
48.5 IVC
57.0 EVO
7.0 EVC
LS2(4.0" x 3.622") with the same 239/244 V.2 Polluter but on a 111+2...events are:
10.5 IVO
48.5 IVC
55.0 EVO
9.0 EVC
Here is a graph overlay showing both cams. Blue line is the LS2, red line is the LS1. Notice that the larger bore LS2 actually peaks later(around 5100 for torque and 6450 for horsepower) and not earlier than the smaller bore LS1(around 4800 for torque and 6250-6300 for horsepower).
This is what I noticed and mentioned to Tooley and he disagreed. I still think that just like Bozz Hawg said that overlap can help carry power further past peak, but I still am left wondering if it actually affects where power peaks and not just before peak and after peak. I mean, I can look at this graph and say, "The only different variables in this equation are a 10cc difference in port volume(from my experience not near enough to change power peak, but it's possible) and 2 degrees of overlap." That still isn't a firm enough stance for me. I'd need to see at least 4-5 more engines with these two cams in them with every other variable being the same as it was in this case to draw a conclusion. It took at least 7-8 5.3 cams for me to realize and ask myself..."Why are these 5.3's peaking so early with these cams?" So I asked an esteemed colleague of mine what he thought and his advice was, "Cam the 5.3 with the same IVC as a 5.7/6.0 and watch what happens." So I did and saw that for the same IVC event as I was using in the larger bore engines, once used in a 5.3 engine with a smaller bore, it produced the same peak power rpm as the larger bore engine did.
LS1(3.898" x 3.622") with the 239/244 112+3 V.2 Polluter. Events are:
10.5 IVO
48.5 IVC
57.0 EVO
7.0 EVC
LS2(4.0" x 3.622") with the same 239/244 V.2 Polluter but on a 111+2...events are:
10.5 IVO
48.5 IVC
55.0 EVO
9.0 EVC
Here is a graph overlay showing both cams. Blue line is the LS2, red line is the LS1. Notice that the larger bore LS2 actually peaks later(around 5100 for torque and 6450 for horsepower) and not earlier than the smaller bore LS1(around 4800 for torque and 6250-6300 for horsepower).
http://s1254.photobucket.com/user/BK...9f1de.jpg.html
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05-29-2014, 06:53 PM
#97
from that it must be exhaust duration then... both the motors had different tuners... Vengeance tunned the 346 while injected tuned the 418... the valvetrain was different on both motors and the 418's exhaust is less restrictive(high flow cats vs no cats if that makes a difference)... the only common factor between the 2 setups is the ported fast 92 and tb and the cold air intake... would that cause it to peak like that due to a restriction... i guess i need more exhaust duration?
05-30-2014, 03:04 PM
#99
yeh i agree, i'm really just interested in finding out the reason the power goes flat at 5800... it does it with this 418 motor, the old 346, and also a buddy of mine has a ls2 gen 1 V and his power does the exact same thing... he has ls3 heads with a baby cam and ls3 intake and different exhaust and different tuner... his power peaks at 5800 and goes flat too... the only thing our cars have in common is the volant CAi... weird huh?