LT4 springs out replace with
LT4 springs out replace with I think you can add another set of hot springs to the list of fails. I can feel them floating like a boat in the upper rpm's. Current valve train is
LT4 hotcam valve springs, retainers and locks - ARP 7/16 studs - Trick Flow guideplates - Wysco stainless 1.6 ratio 7/16 stud mount rockers
Have no interest in camming this motor. Was thinking of going up to 1.7rr's, opinion and parts list would be much appreciated or just going with different springs.
LT4 hotcam valve springs, retainers and locks - ARP 7/16 studs - Trick Flow guideplates - Wysco stainless 1.6 ratio 7/16 stud mount rockers
Have no interest in camming this motor. Was thinking of going up to 1.7rr's, opinion and parts list would be much appreciated or just going with different springs.
How many miles on the springs? Where do you shift? Get a spring compression tester and test at least some of the ones you can get at to see what the seat pressure is see how consistent they are compared (assuming the install height on the springs are all the same).
LoL lead... There wysco 1.6 stainless.. Going to check out the fuel and ignition system to here. Car was pulling great to the 1/8 last night then laid down.. Was running 8.2-8.3's in the 83-84 mph... But running 13.0-13.2's in the 102 area.. Weather around 80 da about 1600-2000 between runs.. Car should be trapping around 104 this time of year and running 12.7-12.8's
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Ok Pancho, i have posted this before but i will share the math here this time as the LT4 springs have less open press with 1.6 rockers than even the stock LT1 spring.
LT4 spring = 332#/in and with stock LT1 cam for '94 intake lift = .450" w/1.5 rockers but = .480" w/1.6 rockers. Then .48" x 332#/in = 159.4# + 101# seat press = only 260.4# open press.
LT1 spring = 373#/in and stock LT1 cam intake lift = .480" w/1.6 rockers. Then .48" x 373#/in = 179# plus 85# seat press = 264# open press.
The exh vlv lifts more making the difference even worse.
So as i expected the LT4 springs were designed for the lighter hollow stem LT4 vlvs.
My suggestion if u don't want to do the head scratching then just go to comps or lunatis w/s and buy their LT1 springs w/retainers and shims. Or read up on the LS6 beehive conversion.
Good luck and i hope this helps more than it hurts,
cardo
LT4 spring = 332#/in and with stock LT1 cam for '94 intake lift = .450" w/1.5 rockers but = .480" w/1.6 rockers. Then .48" x 332#/in = 159.4# + 101# seat press = only 260.4# open press.
LT1 spring = 373#/in and stock LT1 cam intake lift = .480" w/1.6 rockers. Then .48" x 373#/in = 179# plus 85# seat press = 264# open press.
The exh vlv lifts more making the difference even worse.
So as i expected the LT4 springs were designed for the lighter hollow stem LT4 vlvs.
My suggestion if u don't want to do the head scratching then just go to comps or lunatis w/s and buy their LT1 springs w/retainers and shims. Or read up on the LS6 beehive conversion.
Good luck and i hope this helps more than it hurts,
cardo
As has been previously covered valve float over the nose of the cam is extra lift and so long as the lifter isn't bashing the cam up is actually intentionally caused in some racing classes with cam lift limit rules.
The valve float that hurts power is when seat pressure is too low and allows the valve to bounce back off the seat allowing compression to escape.
Think about it, how exactly would the lifter coming off the cam over the nose hurt power? If bad enough it can eventually hurt the cam or lifter but that is not what I am asking about right now. Please explain the exact mechanism by which the valve lifting further than the cam at peak lift hurts power?
If you do want more nose pressure you could also consider shims.
The valve float that hurts power is when seat pressure is too low and allows the valve to bounce back off the seat allowing compression to escape.
Think about it, how exactly would the lifter coming off the cam over the nose hurt power? If bad enough it can eventually hurt the cam or lifter but that is not what I am asking about right now. Please explain the exact mechanism by which the valve lifting further than the cam at peak lift hurts power?
If you do want more nose pressure you could also consider shims.
Last edited by 96capricemgr; Jul 28, 2013 at 09:05 AM.
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Banned
Joined: Jan 2013
Posts: 588
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From: Las Vegas
U would ignore the truth if i told u anyways. Anyone else i would do my best to explain and assist. Basically your not worth the effort. U can google valve float for yourself. Maybe u will believe what u find for yourself.
cardo
cardo
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Verdad Gallardo Ok Pancho, i have posted this before but i will share the math here this time as the LT4 springs have less open press with 1.6 rockers than even the stock LT1 spring.
LT4 spring = 332#/in and with stock LT1 cam for '94 intake lift = .450" w/1.5 rockers but = .480" w/1.6 rockers. Then .48" x 332#/in = 159.4# + 101# seat press = only 260.4# open press.
LT1 spring = 373#/in and stock LT1 cam intake lift = .480" w/1.6 rockers. Then .48" x 373#/in = 179# plus 85# seat press = 264# open press.
The exh vlv lifts more making the difference even worse.
So as i expected the LT4 springs were designed for the lighter hollow stem LT4 vlvs.
My suggestion if u don't want to do the head scratching then just go to comps or lunatis w/s and buy their LT1 springs w/retainers and shims. Or read up on the LS6 beehive conversion.
Good luck and i hope this helps more than it hurts,
cardo
LT4 spring = 332#/in and with stock LT1 cam for '94 intake lift = .450" w/1.5 rockers but = .480" w/1.6 rockers. Then .48" x 332#/in = 159.4# + 101# seat press = only 260.4# open press.
LT1 spring = 373#/in and stock LT1 cam intake lift = .480" w/1.6 rockers. Then .48" x 373#/in = 179# plus 85# seat press = 264# open press.
The exh vlv lifts more making the difference even worse.
So as i expected the LT4 springs were designed for the lighter hollow stem LT4 vlvs.
My suggestion if u don't want to do the head scratching then just go to comps or lunatis w/s and buy their LT1 springs w/retainers and shims. Or read up on the LS6 beehive conversion.
Good luck and i hope this helps more than it hurts,
cardo
Again let's look at this scientifically. By what mechanism does the lifter leaving the cam at peak lift hurt power?
If YOU do a search you will find "lofting" the valves is common in racing. I don't say that to suggest the OP do it on purpose but rather to make the point that it is sometimes done INTENTIONALLY to ADD power. I still want to hear from you exactly how it hurts power.
My point OP is that if you are suffering a high rpm power loss lack of open pressure is NOT the issue. If the back side of the lobes is bashed to hell and the valvetrain comes apart THEN lack of open pressure has caused a problem.
If YOU do a search you will find "lofting" the valves is common in racing. I don't say that to suggest the OP do it on purpose but rather to make the point that it is sometimes done INTENTIONALLY to ADD power. I still want to hear from you exactly how it hurts power.
My point OP is that if you are suffering a high rpm power loss lack of open pressure is NOT the issue. If the back side of the lobes is bashed to hell and the valvetrain comes apart THEN lack of open pressure has caused a problem.
