Upgrading Valve Springs- LS9 using FTS retainers?

[Daniel Jost]

Well I have a question here about fitment of valve springs. I am looking at these valve springs for an LS9 http://www.lingenfelter.com/mm5/mer...arch_Begin_Only=&sort=&range_low=&range_high= and the Full Throttle Speed 105787-12 retainers with 105648-12 locks. I am just running a flat tappet cam at the moment but I feel I am due for a valve spring change with 5+ years on these old school LT1 springs I put in and want to do it right with springs capable of handling the extra lift. Looking at the specs on the springs it looks like they are good for .580' lift and 1.19" coil bind height so it looks like they would be great even for a roller cam swap I see in my near future! Can anyone verify that these clear or if I would have any issues, any thing like that?

Thanks, Dan

 

[forcefed3.8's]

What are the open and closed pressures? At 1.19" coilbind, there is room for .580 at 1.8 installed height. Most likely you will be under 1.8.

As far as a roller, they probably don't have enough pressure. Maybe too much for a flat tappet.

 

[Daniel Jost]

They are rated at 90# at 1.8" and something like 295# at 1.19

Thanks, Dan

 

[S10xGN]

What are the open and closed pressures? At 1.19" coilbind, there is room for .580 at 1.8 installed height. Most likely you will be under 1.8.

As far as a roller, they probably don't have enough pressure. Maybe too much for a flat tappet.

The LS9 is a roller cammed engine, with the same installed height he should be good either way. I'd run them on a flat tappet cam that was already broken in properly, not sure I'd put them on a new install though...

 

[forcefed3.8's]

Not enough pressure for a roller in a Buick, not even close. Should work with a flat tappet. As always, check installed height, open and closed pressure.

These LS engines have super light valvetrain and soft profile cams, and don't have 20+psi pushing the intake valve not to mention 40+psi pushing on the exhaust valve.

 

[S10xGN]

Not enough pressure for a roller in a Buick, not even close. Should work with a flat tappet. As always, check installed height, open and closed pressure.

These LS engines have super light valvetrain and soft profile cams, and don't have 20+psi pushing the intake valve not to mention 40+psi pushing on the exhaust valve.

Ooookaaay...

 

[forcefed3.8's]

Sorry, enlighten me.

 

[turbofabricator]

If those figures afe correct, they will work fine. Installed highth is uually around 1.75" with standard keepers. So with FTS -.050" keepers that will get you right in the ball park for flat tappet. (But only till it goes flat on ya.)

 

[bison]

You better check the spring pressures@ heights to verify whats really getting put on there. Nothing like scratching your ass for hours later wondering if the springs could be a problem

 

[S10xGN]

Not enough pressure for a roller in a Buick, not even close. Should work with a flat tappet. As always, check installed height, open and closed pressure.

These LS engines have super light valvetrain and soft profile cams, and don't have 20+psi pushing the intake valve not to mention 40+psi pushing on the exhaust valve.

Sorry, enlighten me.

OK, according to (post #29) "Beau" at Scoggins-Dickey, in regards to valve springs, says: "LS2/3/6/9 are all the same number".

That said, here are the specs for an LS6 spring:

GMPP # 12586484 beehive Style valve springs standard LS6/LS3 springs
1.800" installed height @ 90 # pressure
1.250" @ 295 # pressure
Max lift 0.570"
373 lbs / in spring rate
1.19" coil bind

If these springs can adequately control a 2.20" intake valve on an LS9 to 7000 RPM, I'm pretty confident they work with a Buick 1.71" valve at - what - 5800 RPM? As for the "low" seat pressure (90#) at the 1.800" installed height, I don't think that would be an issue either. I haven't seen many off-the-shelf Buick rollers with more than 0.520" lift so theoretically he could set them at 1.75", gain 18# more seat pressure and still be 0.050" from coil bind. And I can't buy into your argument about the effects of boost pressure on the valves either, as the stock springs only had 80# seat pressure...

 

[bison]

If these springs can adequately control a 2.20" intake valve on an LS9 to 7000 RPM, I'm pretty confident they work with a Buick 1.71" valve at - what - 5800 RPM? As for the "low" seat pressure (90#) at the 1.800" installed height, I don't think that would be an issue either. I haven't seen many off-the-shelf Buick rollers with more than 0.520" lift so theoretically he could set them at 1.75", gain 18# more seat pressure and still be 0.050" from coil bind. And I can't buy into your argument about the effects of boost pressure on the valves either, as the stock springs only had 80# seat pressure...

You better keep thinkin' .

 

[S10xGN]

You better keep thinkin' .

My turn... "Enlighten me".

So, if an LS9 spring with 90# seat pressure can control a 2.20" (3.799 sq in) valve with 7 or 8 # of boost on it, you're saying this little bitty 1.71" (2.295 sq in) valve with 25# on will be out of control?

Not seein' it, so make me understand...

 

[bison]

Try it and you will understand. You would be ok with a stock cam @25psi with those pressures. Ive posted enough about springs and how many inadequate springs ive replaced. Ive seen cars pick up 200whp with spring changes and drop nearly a second of their e.t. Some had small hyd flat cams with a lot less lift than you mentioned.