106 lsa on LS3
106 lsa on LS3 
06-29-2019, 03:07 AM
#2
If you wanted to run a 106LSA you would need something quite radical to get a decent power band, but the downside is you will have too much overlap which can cost you power if there is too much of it.
For example if you had a daily driven grind like a 225/238 on a 115 LSA +2 this would drive nicely with good torque everywhere and will pull to 6500rpm nicely with 1.5 degrees of overlap.
Change the LSA to 106 and your overlap goes to 19.5 degrees.
Then, your IVC is way too early and your EVO is way too late so you will not make good top end power and your powerband will be narrow concentrated lower in the rpm band
It will also not make good low end torque either because of the overlap.
Idle vacuum, would depend on what car it's in and the setup etc.
Too many variables.
07-01-2019, 04:03 PM
#3
While not a 106 LSA, I have the LSX454 cam in my 6.2 LS7.
236/246 @ .050 110+1 LSA - 21 degrees of overlap - .648"/.648" lift with 1.8 rockers
IVO - 9° BTDC IVC - 47° ABDC
EVO - 54° BBDC EVC - 12° ATDC
The kPa at idle is only 58-60. It certainly isn't happy below 1900 or so. Makes freeway driving in 6th gear a pain in the ***.
It has PLENTY of top end power though. I set the rev limiter to 7200 just because I feel bad for the stock crank and rods.
236/246 @ .050 110+1 LSA - 21 degrees of overlap - .648"/.648" lift with 1.8 rockers
IVO - 9° BTDC IVC - 47° ABDC
EVO - 54° BBDC EVC - 12° ATDC
The kPa at idle is only 58-60. It certainly isn't happy below 1900 or so. Makes freeway driving in 6th gear a pain in the ***.
It has PLENTY of top end power though. I set the rev limiter to 7200 just because I feel bad for the stock crank and rods.
07-01-2019, 09:52 PM
#4
While not a 106 LSA, I have the LSX454 cam in my 6.2 LS7.
236/246 @ .050 110+1 LSA - 21 degrees of overlap - .648"/.648" lift with 1.8 rockers
IVO - 9° BTDC IVC - 47° ABDC
EVO - 54° BBDC EVC - 12° ATDC
The kPa at idle is only 58-60. It certainly isn't happy below 1900 or so. Makes freeway driving in 6th gear a pain in the ***.
It has PLENTY of top end power though. I set the rev limiter to 7200 just because I feel bad for the stock crank and rods.
236/246 @ .050 110+1 LSA - 21 degrees of overlap - .648"/.648" lift with 1.8 rockers
IVO - 9° BTDC IVC - 47° ABDC
EVO - 54° BBDC EVC - 12° ATDC
The kPa at idle is only 58-60. It certainly isn't happy below 1900 or so. Makes freeway driving in 6th gear a pain in the ***.
It has PLENTY of top end power though. I set the rev limiter to 7200 just because I feel bad for the stock crank and rods.
07-02-2019, 03:04 PM
#6
Running any cam on a 106 LSA on an LS3 would not be ideal as the valve events would be too early and you would have no top end.
If you wanted to run a 106LSA you would need something quite radical to get a decent power band, but the downside is you will have too much overlap which can cost you power if there is too much of it.
For example if you had a daily driven grind like a 225/238 on a 115 LSA +2 this would drive nicely with good torque everywhere and will pull to 6500rpm nicely with 1.5 degrees of overlap.
Change the LSA to 106 and your overlap goes to 19.5 degrees.
Then, your IVC is way too early and your EVO is way too late so you will not make good top end power and your powerband will be narrow concentrated lower in the rpm band
It will also not make good low end torque either because of the overlap.
Idle vacuum, would depend on what car it's in and the setup etc.
Too many variables.
If you wanted to run a 106LSA you would need something quite radical to get a decent power band, but the downside is you will have too much overlap which can cost you power if there is too much of it.
For example if you had a daily driven grind like a 225/238 on a 115 LSA +2 this would drive nicely with good torque everywhere and will pull to 6500rpm nicely with 1.5 degrees of overlap.
Change the LSA to 106 and your overlap goes to 19.5 degrees.
Then, your IVC is way too early and your EVO is way too late so you will not make good top end power and your powerband will be narrow concentrated lower in the rpm band
It will also not make good low end torque either because of the overlap.
Idle vacuum, would depend on what car it's in and the setup etc.
Too many variables.
07-02-2019, 04:50 PM
#7
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07-02-2019, 05:04 PM
#8
I was looking at the camshaft specs you have for a stock displacement LS3.
They are definitely decent and the valve events are ok however if I had this engine I would have fitted a 236/246 112 LSA +3
Not only would you have a little calmer idle, but you would make more power from the upper mid range and top end due to the earlier Evo.
I was a bit confused thinking you had a 427 LS3 when I saw the 4.070 bore size.
If you had a 427 that camshaft spec would need to be on a 116 LSA +3 for the same effect.
07-03-2019, 11:06 AM
#10
Ok.
I was looking at the camshaft specs you have for a stock displacement LS3.
They are definitely decent and the valve events are ok however if I had this engine I would have fitted a 236/246 112 LSA +3
Not only would you have a little calmer idle, but you would make more power from the upper mid range and top end due to the earlier Evo.
I was a bit confused thinking you had a 427 LS3 when I saw the 4.070 bore size.
If you had a 427 that camshaft spec would need to be on a 116 LSA +3 for the same effect.
I was looking at the camshaft specs you have for a stock displacement LS3.
They are definitely decent and the valve events are ok however if I had this engine I would have fitted a 236/246 112 LSA +3
Not only would you have a little calmer idle, but you would make more power from the upper mid range and top end due to the earlier Evo.
I was a bit confused thinking you had a 427 LS3 when I saw the 4.070 bore size.
If you had a 427 that camshaft spec would need to be on a 116 LSA +3 for the same effect.
I would probably go with a 228/238 on a 114+4 with as much lift as I could get for better street manners.
07-03-2019, 06:59 PM
#11
I agree. Not my first choice of cam for a daily driven street car, but the bare heads and cam were free to me and I had a set of stock LS7 Ti Intake valves and bought a set of one piece stainless exhaust valves from SI Valves.
I would probably go with a 228/238 on a 114+4 with as much lift as I could get for better street manners.
I would probably go with a 228/238 on a 114+4 with as much lift as I could get for better street manners.
225/238 115 LSA+3.
1.5 degrees of overlap and will be stock like in its operation and pull well everywhere and carry great to 6500rpm.
07-03-2019, 07:37 PM
#13
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Originally Posted by bortous
So accounting for the lash there would be approximately 7 degrees taken off each side.
07-07-2019, 07:08 PM
#15
While not a 106 LSA, I have the LSX454 cam in my 6.2 LS7.
236/246 @ .050 110+1 LSA - 21 degrees of overlap - .648"/.648" lift with 1.8 rockers
IVO - 9° BTDC IVC - 47° ABDC
EVO - 54° BBDC EVC - 12° ATDC
The kPa at idle is only 58-60. It certainly isn't happy below 1900 or so. Makes freeway driving in 6th gear a pain in the ***.
It has PLENTY of top end power though. I set the rev limiter to 7200 just because I feel bad for the stock crank and rods.
236/246 @ .050 110+1 LSA - 21 degrees of overlap - .648"/.648" lift with 1.8 rockers
IVO - 9° BTDC IVC - 47° ABDC
EVO - 54° BBDC EVC - 12° ATDC
The kPa at idle is only 58-60. It certainly isn't happy below 1900 or so. Makes freeway driving in 6th gear a pain in the ***.
It has PLENTY of top end power though. I set the rev limiter to 7200 just because I feel bad for the stock crank and rods.
I guess I should say... are you reading the gauge or HPTuners? HPT subtracts what you'd see on a gauge from 100 kPa (~29" hg) and displays what's left. I've daily driven cars that idle at 70 kPa in HPT (or around 9.5" of vacuum on a gauge).
07-08-2019, 02:09 PM
#16
kPa of 58 at idle should drive pretty good. I'm surprised you get that reading though with that much overlap in a 376.
I guess I should say... are you reading the gauge or HPTuners? HPT subtracts what you'd see on a gauge from 100 kPa (~29" hg) and displays what's left. I've daily driven cars that idle at 70 kPa in HPT (or around 9.5" of vacuum on a gauge).
I guess I should say... are you reading the gauge or HPTuners? HPT subtracts what you'd see on a gauge from 100 kPa (~29" hg) and displays what's left. I've daily driven cars that idle at 70 kPa in HPT (or around 9.5" of vacuum on a gauge).
I have played with EOIT quite a bit to find a good balance of raw fuel smell at idle, bucking on the freeway (1600-1800 RPM) and fuel mileage. All of my playing around with EOIT has moved the Idle kPa around some as well. Idle Spark Timing has also had an effect on the Idle kPa.
07-08-2019, 04:20 PM
#17
Yeah... I would think 24-28 degrees idle spark would be ideal to lower the kPa and make it idle better. However, the smell reduces as you get closer to 18 degrees...
And as an aside, you should try to richen it up and reduce spark in the areas where it is bucking in that 1600-2000 range. It seems counter-intuitive... but enrichen the hell out of it and drop your spark advance to 22 degrees or less. It'll help.
And as an aside, you should try to richen it up and reduce spark in the areas where it is bucking in that 1600-2000 range. It seems counter-intuitive... but enrichen the hell out of it and drop your spark advance to 22 degrees or less. It'll help.
07-08-2019, 05:59 PM
#18
Yeah... I would think 24-28 degrees idle spark would be ideal to lower the kPa and make it idle better. However, the smell reduces as you get closer to 18 degrees...
And as an aside, you should try to richen it up and reduce spark in the areas where it is bucking in that 1600-2000 range. It seems counter-intuitive... but enrichen the hell out of it and drop your spark advance to 22 degrees or less. It'll help.
And as an aside, you should try to richen it up and reduce spark in the areas where it is bucking in that 1600-2000 range. It seems counter-intuitive... but enrichen the hell out of it and drop your spark advance to 22 degrees or less. It'll help.
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07-28-2019, 06:31 PM
#20
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Likewise, I have a CamMotion Titan 4, 227-232 on a 113 in a 347 very similar to what you have and it performs really well, doesn’t buck, idle quality is excellent, couldnt be happier with its drivability, I do have higher than average compression with 11.65:1 and a 3” exh system with X pipe and low restriction cats to help keep it quiet.