recommended springs 5.3 L33 high rpm duty
#21
TECH Senior Member
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Only in the past year or so have I heard about shimming to .050 before CB. Does that stabilize spring harmonics or is it something simpler than that?
#23
TECH Senior Member
#24
TECH Fanatic
iTrader: (7)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
To the OP, I'm running some howard springs that are $120 ish, single beehive with the same if not slightly better specs than the PAC 1218s. Max lift is .600" and Ive spun my 5.3 with the above 218/228 .561/.561 cam to 6500 with 11psi and no issues or float, dropped onto my stock ported 862s with stock retainers and locks etc.
Specs:
115lb closed
332lb open
412 spring rate
.600" max lift
coil bind is 1.150"
https://www.summitracing.com/parts/hrs-98113
Specs:
115lb closed
332lb open
412 spring rate
.600" max lift
coil bind is 1.150"
https://www.summitracing.com/parts/hrs-98113
#26
FormerVendor
iTrader: (1)
Join Date: Nov 2008
Location: Santa Ana, CA. USA
Posts: 2,157
Likes: 0
Received 17 Likes
on
17 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hi ALL, I should add 115 Seat is not a good choice for a Turbo Charged EX (EMAP Value ???) Valve Spring.
The Joe Nova "tech" is a report I too agree with, the EAP error %.
I find the RPM points are often OFF by 500.
The other items such as PV/Valve Float/C.R./Piston Speed are correct with NO ERROR.
Thus, thanks Joe for your report as a user of EAP OR EAP Pro ?
Lance
The Joe Nova "tech" is a report I too agree with, the EAP error %.
I find the RPM points are often OFF by 500.
The other items such as PV/Valve Float/C.R./Piston Speed are correct with NO ERROR.
Thus, thanks Joe for your report as a user of EAP OR EAP Pro ?
Lance
#27
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hi ALL, I should add 115 Seat is not a good choice for a Turbo Charged EX (EMAP Value ???) Valve Spring.
The Joe Nova "tech" is a report I too agree with, the EAP error %.
I find the RPM points are often OFF by 500.
The other items such as PV/Valve Float/C.R./Piston Speed are correct with NO ERROR.
Thus, thanks Joe for your report as a user of EAP OR EAP Pro ?
Lance
The Joe Nova "tech" is a report I too agree with, the EAP error %.
I find the RPM points are often OFF by 500.
The other items such as PV/Valve Float/C.R./Piston Speed are correct with NO ERROR.
Thus, thanks Joe for your report as a user of EAP OR EAP Pro ?
Lance
#28
Restricted User
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
115 lbs is considered low seat pressure for a turbo application and makes some worry about valve float.
Its still more seat pressure than LS6 springs (90 lbs), and has a much higher pressure rate when compared to PAC1218s (412 lbs/in vs 313 lbs/in) resulting in better overall valve control.
Lance's point is that none of those 3 springs is typically recommended for turbocharged engines due to either low seat pressure or low spring rate.
But when they work, they work.
Its still more seat pressure than LS6 springs (90 lbs), and has a much higher pressure rate when compared to PAC1218s (412 lbs/in vs 313 lbs/in) resulting in better overall valve control.
Lance's point is that none of those 3 springs is typically recommended for turbocharged engines due to either low seat pressure or low spring rate.
But when they work, they work.
#29
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
115 lbs is considered low seat pressure for a turbo application and makes some worry about valve float.
Its still more seat pressure than LS6 springs (90 lbs), and has a much higher pressure rate when compared to PAC1218s (412 lbs/in vs 313 lbs/in) resulting in better overall valve control.
Lance's point is that none of those 3 springs is typically recommended for turbocharged engines due to either low seat pressure or low spring rate.
But when they work, they work.
Its still more seat pressure than LS6 springs (90 lbs), and has a much higher pressure rate when compared to PAC1218s (412 lbs/in vs 313 lbs/in) resulting in better overall valve control.
Lance's point is that none of those 3 springs is typically recommended for turbocharged engines due to either low seat pressure or low spring rate.
But when they work, they work.
#30
Restricted User
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
The recommended PSI 1511ML springs have 130 lbs seat pressure. They have less spring rate than the Howard's springs though, so take it as you want.
Seat pressure is more important with heavy valves and turbo backpressure.
Seat pressure is more important with heavy valves and turbo backpressure.
#31
FormerVendor
iTrader: (1)
Join Date: Nov 2008
Location: Santa Ana, CA. USA
Posts: 2,157
Likes: 0
Received 17 Likes
on
17 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hi CBB, sure a fair request, thanks.
Let us state a MAP of 15.lbs with common EMAP of 30.lbs (single turbo NOT twins)
Let us state a Exhaust Valve diameter of 1.6 = .8 radius x .8 = .6 x 3.14 = 1.884 x 30psi = 56 .lbs of seat pressure reduction.
NOW ADD the Oil Pressure of the HYD (??) lifter using the same math with further reduction observed divider by rocker ratio.
The same math is on the intake 2" valve seat pressure, 1 x 3.14 x 15 = 46 .lbs reduction + Hyd Lifter's Oil Pressure.
BOTTOM LINE is to measure your EMAP ?
NOW ALL should UNDERSTAND Spring Weight, the MOVING SIDE IS VALVE WEIGHT. (retainer/keepers AND 1/2 spring weight measured)
THUS ANOTHER reason to use the PSI 1511ML. (conical)
Lance
Let us state a MAP of 15.lbs with common EMAP of 30.lbs (single turbo NOT twins)
Let us state a Exhaust Valve diameter of 1.6 = .8 radius x .8 = .6 x 3.14 = 1.884 x 30psi = 56 .lbs of seat pressure reduction.
NOW ADD the Oil Pressure of the HYD (??) lifter using the same math with further reduction observed divider by rocker ratio.
The same math is on the intake 2" valve seat pressure, 1 x 3.14 x 15 = 46 .lbs reduction + Hyd Lifter's Oil Pressure.
BOTTOM LINE is to measure your EMAP ?
NOW ALL should UNDERSTAND Spring Weight, the MOVING SIDE IS VALVE WEIGHT. (retainer/keepers AND 1/2 spring weight measured)
THUS ANOTHER reason to use the PSI 1511ML. (conical)
Lance
#32
LS1Tech Premium Sponsor
iTrader: (2)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Maybe im missing where this math is coming from. if the boost is pushing DOWN on the valve, then it would only be lost theoretically as the valve is coming UP....and you also forgot to subtract the stem circumference/area.
But your math deals with a flat surface, and the back of a valve is not...so calculate that correctly first then maybe the math will pan out...but still a reach.
But your math deals with a flat surface, and the back of a valve is not...so calculate that correctly first then maybe the math will pan out...but still a reach.
Last edited by tech@WS6store; 05-11-2018 at 02:21 PM.
#33
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
That's complete and utter nonsense. You don't start looking at big cams for more flow only to restrict the flow in your heads.
#34
FormerVendor
iTrader: (1)
Join Date: Nov 2008
Location: Santa Ana, CA. USA
Posts: 2,157
Likes: 0
Received 17 Likes
on
17 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hi WS6, I am extremely concerned WHY you report my Maths are incorrect AND the fact that your report purpose is ONLY TO SPLIT A HAIR !
ALLOW me to EXPLAIN to ALL about the instant pressures inside a cylinder during a cycle.
When the piston is at TDC OVERLAP it moves away from the cylinder head "PULLING" the Valves Open due to LOW pressure in the cylinder, lower than the pressure in BOTH ports. (IN + EX Ports)
This pressure timing (piston/valve) is at worst possible time as the EX Valve is just seating AND the possible delay could, often does, allow Exhaust Gasses (hot gasses) to enter the cylinder when EX Valve seat pressure is to low. (seat bounce)
MY first Empirical observation was in 1994 for the AURA Camless Ranger Ford 2300 Twin Plug on my bench dyno.
A Kistler sensor was placed in one of the sparkplug holes, the valves were electromagnetic in operation controlled with MY ECU.
THUS as easy data log of instant cylinder pressure vs piston position.
ONE AURA requested test, from Borg Warner, was to create a cycle with Internal EGR, opening the EX Valve during the Intake Phase.
This worked fine when my ECU was used, commanding the EX Valve to open at the requested time in the cycle.
The BW engineers were VERY pleased to witness their theory proven (Internal EGR) in engine operation, a FIRST on this planet.
MY GUESS is that LS-1 Tech members DO NOT like mixing Exhaust Gases with Intake Gases in their engines.
Lance.
ALLOW me to EXPLAIN to ALL about the instant pressures inside a cylinder during a cycle.
When the piston is at TDC OVERLAP it moves away from the cylinder head "PULLING" the Valves Open due to LOW pressure in the cylinder, lower than the pressure in BOTH ports. (IN + EX Ports)
This pressure timing (piston/valve) is at worst possible time as the EX Valve is just seating AND the possible delay could, often does, allow Exhaust Gasses (hot gasses) to enter the cylinder when EX Valve seat pressure is to low. (seat bounce)
MY first Empirical observation was in 1994 for the AURA Camless Ranger Ford 2300 Twin Plug on my bench dyno.
A Kistler sensor was placed in one of the sparkplug holes, the valves were electromagnetic in operation controlled with MY ECU.
THUS as easy data log of instant cylinder pressure vs piston position.
ONE AURA requested test, from Borg Warner, was to create a cycle with Internal EGR, opening the EX Valve during the Intake Phase.
This worked fine when my ECU was used, commanding the EX Valve to open at the requested time in the cycle.
The BW engineers were VERY pleased to witness their theory proven (Internal EGR) in engine operation, a FIRST on this planet.
MY GUESS is that LS-1 Tech members DO NOT like mixing Exhaust Gases with Intake Gases in their engines.
Lance.
#36
Restricted User
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Put 317s on a 5.3 and watch both power and torque completely tank vs the stock 862/706 heads.
Why do you think people mill the 243/799 heads .030 when swapping them onto their 5.3? Because the compression loss outweighs the flow gains.
Its not like it hasn't been tested. 5 minutes with google can save you embarassment.
![](http://image.superchevy.com/f/156904161+w640+h640+q80+re0+cr1+st0/018-dyno-graph.jpg)
http://www.superchevy.com/how-to/eng...der-head-test/
#37
FormerVendor
iTrader: (1)
Join Date: Nov 2008
Location: Santa Ana, CA. USA
Posts: 2,157
Likes: 0
Received 17 Likes
on
17 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Hi ALL, let us believe in the WS6 report of area reduction caused by the Valve Stem = OK
THUS that area reduction would cause a CHANGE of LESS THAN ONE Pound (.74) of seat pressure with a measured EMAP of thirty (30) PSI.
The fair is fair about reports posted on LS-1 tech is observed.
The BEST item is the general agreement with respect to Valve Seat Pressure Requirement for a Turbo Engine.
Lance
THUS that area reduction would cause a CHANGE of LESS THAN ONE Pound (.74) of seat pressure with a measured EMAP of thirty (30) PSI.
The fair is fair about reports posted on LS-1 tech is observed.
The BEST item is the general agreement with respect to Valve Seat Pressure Requirement for a Turbo Engine.
Lance
#38
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
If the heads aren't a restriction in the first place, then its irrelevant.
Put 317s on a 5.3 and watch both power and torque completely tank vs the stock 862/706 heads.
Why do you think people mill the 243/799 heads .030 when swapping them onto their 5.3? Because the compression loss outweighs the flow gains.
Its not like it hasn't been tested. 5 minutes with google can save you embarassment.
![](http://image.superchevy.com/f/156904161+w640+h640+q80+re0+cr1+st0/018-dyno-graph.jpg)
http://www.superchevy.com/how-to/eng...der-head-test/
Put 317s on a 5.3 and watch both power and torque completely tank vs the stock 862/706 heads.
Why do you think people mill the 243/799 heads .030 when swapping them onto their 5.3? Because the compression loss outweighs the flow gains.
Its not like it hasn't been tested. 5 minutes with google can save you embarassment.
![](http://image.superchevy.com/f/156904161+w640+h640+q80+re0+cr1+st0/018-dyno-graph.jpg)
http://www.superchevy.com/how-to/eng...der-head-test/
#39
TECH Senior Member
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
5.3L = 323 cu. in. Pretty close.....
#40
Restricted User
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
The L33 has flat top pistons you dumbass. And it only takes a decent size cam to put a 5.3 well past the power levels of any stock 5.7 - so are you saying the 243/799 heads were too big for those as well? Also - superchevy are a bunch of retards, they think the 5.3 is a 327. You’ve been schooled. Buh bye now.
If you look at the dyno graph I just showed you, it was on a 470 HP 5.3. I'm sure if the 706 heads on that combo were a restriction at even 470 HP, it would have gained power with the 799s. It didn't.
243s too big for a stock 5.7? No, the 243s have smaller chambers than stock LS1 heads, so you get a compression bump from them. Flow aside, they gain power.
With heads, you have to balance compression and flow. You're not going to pick up horsepower with a 500 CFM head if it drops your compression to 6:1. Unfortunately, even the 706/862 heads flow enough for a 5.3, and a 243/799 on the same combo generally results in power loss.
If you want to come try it out for yourself, I have an engine dyno and some 5.3s ready. You're more than welcome to try and prove me wrong.