So LT4 valve springs are speced at 1.75 installed height I believe. Now if I was to use these in my motor--which i plan to do, stock LT1 cam with 1.6 rockers I could decrease the installed height (for example 1.70) a little bit to gain a little more pressure.

What is the spec for the stock LT1 cam? I just need to find what lift I would have with 1.6 rockers and stock cam, then i could bump the installed height down, so I would be using more of the springs pressure.


Would this work? Disadvantages?, Advantages?

Or is this just absolutely stupid idea?

 

As or right now I am just checking spring pressures before install them.

What is the lift of the stock LT1 cam?

 

The stock cam has a lift of .298i/.306e. So with 1.6 rocker ratio, you get .477 and .490 on the stock cam.

With a 1.70 install height, and a .490 max lift, you get 1.21 max compression on the spring. Do you know the LT4 spring specs? (bind number, seat pressure @ 1.75, spring rate)

Thomas.

 

Ya won't see any "gains" from making the installed height shorter. Put them in at stock height and make sure ya use the LT4 retainers and keepers. I didn't and it cost me an engine.

 

What happened? A keeper fall off??
Yea am using LT4 springs/retaineers/keepers the whole set.


Thanks


So I should set it up @ 1.75 installed height? So extra seat pressure won't help at high rpms?

 

No the stock retainer folded up @6000.

Extra seat pressure in your set up won't help. Now if ya had a 230/240@50 cam ya would want to go up on the pressure because of the ramp speed so ya could control the valve. Stock cam, no help.

 

Alright thanks. So stock installed height is 1.750" right?