LS1 Valve springs on my 01

[john_V63400]

ok guys I read the forum below and I want to swap some LS1 srings in my 01 3400. Can some one give me Detailed instructions so I can give them to my mechanic and he can swap them out with ease with out problems. Possibly give me part # and all that if available. Thanks

[JMo60]

im using ls-1 springs on my 3400. much stiffer than stock. the spring will fit as long as you grind a little on the inner diameter of the bottom spring for valve guide clearance... they work excelent for me

[IsaacHayes]

IIRC, there was another post down below this one that talked about what was needed..

How come everyone goes to these springs? Unless you are using a cam or have your shift points higher what is the purpose? Some people I see with springs but no cam. I don't get it.

[SappySE107]

You removed metal from the spring? Wow, no way is that a good idea. Im not even sure I understand what you are talking about with the guide clearance. LS1 springs aren't a lot stiffer than stock but they would be good for a stock to near stock application.

Springs get weaker with age, so if you start with a slightly stiffer spring it will still perform to spec or above for longer than a stocker would.

[Blackrider]

http://www.grandamgt.com/forum/showthread.php?t=51512&highlight=Spring+Swap

[AaronGTR]

im using ls-1 springs on my 3400. much stiffer than stock. the spring will fit as long as you grind a little on the inner diameter of the bottom spring for valve guide clearance... they work excelent for me

They aren't actually that much stiffer than a stock 3400 spring. They are just stiff enough though to eliminate valve float problems you can get with the stock springs and a stock cam after some miles or hard running, addition of NOS/boost etc. And yeah, you definitely don't want to grind the springs at all as that will weaken them. You only need to grind the shims on 2001+ heads. I hope thats what you meant.

[SappySE107]

Depends on your idea of a little or a lot.

Stock
1.7" 78#
1.3" 157#

LS1
1.7" 106#
1.3" 177#

LS6
1.7" 121#
1.3" 203#

[JMo60]

pretty much what im talking about is i lightly filed the bottom lip to get rid of the small bur, no problems at all, i only took maybe .002 at the most
I love it when people start adding NOS or nawz

[AaronGTR]

Depends on your idea of a little or a lot.

Stock
1.7" 78#
1.3" 157#

LS1
1.7" 106#
1.3" 177#

LS6
1.7" 121#
1.3" 203#

Don't know where you got that info but it's wrong. According to the GM service info....

For a 3400 in a 2000 grand am.
LA1 springs: 75lb @ 1.701"
230lb @ 1.260"

For an LS1 in a 1998 C5 vette
LS1 springs: 76lb @ 1.8"
220lb @ 1.32"

The LS1 has a max valve lift of .479" on the exhaust. LA1 has valve lift of .436". If you take into account the LA1's lower install height of .1", then the LS1 spring pressure will be slightly stiffer than the LA1 spring when installed on a LA1 engine, especially when the valve is closed. Thats why I said "slightly".

[SappySE107]

I wouldn't trust the GM manual over a real world test. I had the springs tested at the machine shop.

[DarksideGA]

What kinda of tensions were you getting off the ls1 springs? Now I am a little skeptical about spending the dough to install these if theyre only 76 at 1.8 and then 10 pounds less than stock when compressed.....

[SappySE107]

Depends on your idea of a little or a lot.

Stock
1.7" 78#
1.3" 157#

LS1
1.7" 106#
1.3" 177#

LS6
1.7" 121#
1.3" 203#

[AaronGTR]

What kinda of tensions were you getting off the ls1 springs? Now I am a little skeptical about spending the dough to install these if theyre only 76 at 1.8 and then 10 pounds less than stock when compressed.....

You're forgetting about the .1" difference in install height. They are at 1.8" on the LS1 and 1.7" on the LA1. That means they'd be stiffer than stock when closed. Also the LS1 springs open pressure rating is .06" less compression than the LA1 height, so you have to remember to add .1" to that too. .436" of lift on a LA1 is like .536" on a LS1 compared to stock .479". Basically the spring is compressed more at all times on the LA1 so the pressures are higher than those numbers.


Sappy, no offense or anything but I'm inclined to believe GM more than a shop that I don't know and have no way of knowing what testing methods or equipment they used to test with. I would think on mass produced engines like these and especially a performance engine like the LS1 that their engineers would have to be pretty specific about having the correct spring rate and that production tolerances would have to be pretty low. It is required to guarantee longevity of the engine. That and I'm sure GM has more accurate testing equipment available than a small shop. In fact, the open pressures you list are so much lower I'd almost think they were testing used springs. I just can't swallow them being off by that large a margine. Just my opinion.

[SappySE107]

I have had new comp cam springs tested to reflect their rated spring pressure. If someone else wants to get the springs checked, that would be great. I have them check 1.7 and 1.3 to keep it consistant. The springs I had tested were either new or very low milage. I did notice the LS1 springs I see now are tall/skinny and the one I tested looks more like the LS6.

[Superdave]

here is a pic of mine instaled on '02 3400 heads...

the valve seals are for a '92 2.2 liter cavalier and they fit perfect. no smoke at all when i start it up. :P