Valvetrain Geometry?

[BriannFlintZ24]

This is my first post on 60degreev6 but I have been lurking for several months, mostly when doing research on a 3400 I am building for my '92 Cavalier Vert.

First I would like to thank everyone on the site for the information that it provides, even for people who do not participate. For nearly every question I have had thus far I have found answers here.

Now this may be a dumb question, but i'll ask anyways.

I recently sent my cam to Crower for regrinding. The specs have not been determined thus far, but I plan to take about as far as it can go, which brings me to valve springs.

In a recent thread about springs, it was suggested that for up to .470-.500 lift the LS1/LS2 springs will work.. In that thread it was brought up that the install height of the 3400 is .100 lower than the LS1/LS2 springs are rated at, changing the geometrics of the spring.

Summit Racing (and Jeggs, etc) sell valve locks with +.100 install height for SBC. Are these compatable with the valves we use, and would it increase the install height of the springs to restore proper spring rates using the LS1/LS2 springs?

Which brings me to my next question..

If I change the install height of the springs will I run into any clearance or geometric issues?

[geoffinbc]

I dont know if has been done when the guys swap to LSx springs but I am pretty confident that you can use an LSx retainer on our stems to give the right install height.
If the difference in install height is due to the valve stem then I would wait for spring pressure recommendations from Comp. Once you know this you can choose from an LS1 or LS6 spring. I would not jump right to an LS6 spring because if its install height is smaller by .100 the you will change the seat and open pressure. You may not even require this much pressure so there is no sense in overkill. Having a spring at a shorter install height is not a big deal you just have to be aware of the different pressure.

[Froggx]

When crower sent my cam back they left the recommended spring pressures blank on the cam card which somewhat leaves me in the dark. On Brad's cam card they did the same thing. So it might not be the best of ideas to wait for those on spring choice.

[geoffinbc]

Well I would go a look for cams that are ground close to that specification.

For any street cam Crane recommends their 99848 springs which are a bit higher than stock 600 springs

[v6h.o.]

Re: Valvetrain Geometry?

In a recent thread about springs, it was suggested that for up to .470-.500 lift the LS1/LS2 springs will work.. In that thread it was brought up that the install height of the 3400 is .100 lower than the LS1/LS2 springs are rated at, changing the geometrics of the spring.

Summit Racing (and Jeggs, etc) sell valve locks with +.100 install height for SBC. Are these compatable with the valves we use, and would it increase the install height of the springs to restore proper spring rates using the LS1/LS2 springs?

Which brings me to my next question..

If I change the install height of the springs will I run into any clearance or geometric issues?

The LS2 springs are the exact spring and part number of LS6 springs. LS2/6 springs are roughly 4 X's the price of LS1 springs. which is something to be noted.

The fact that the springs are installed a bit tighter compared to the stock rating for the LS1 springs is not a bad thing. This gives them a bit higher spring tension at those installed heights.

You wont be able to restore the Stock LS1 installed height because its not due to the retainers its due to the fact that the space between the spring seat and the retainer is less. You would have to cut the valve seat down to restore it. Or use a thinner spring seat (shim)

I would not try and worry about the installed height of the LS1 spring at 3X00 installed heights. It will be fine. It gives them that extra bit of pressure at those heights. I've ran these springs with full LS1 retainers/locks and shims for 4+years with no issues of wiping a cam lobe.

You wont run into any clearance of geometric issues as the Valve tip has not changed location and if you use the 3x00 retainers/locks they are the same as if it was a stock spring under there so clearance around the valve tip from the retainer will stay the same for the rocker arm tip.

The camshaft lobe change will cause more of a valvetrain clearance issue which depending on what rockers you are using with determine what you need to do to compensate.

[geoffinbc]

I agree it would not be bad to use an LS1 spring under a 3X00 retainer. The pressure will not be that high. But an LS6 spring will be farily high. Probabally not required by any streetable cam you would select.

[v6h.o.]

I agree it would not be bad to use an LS1 spring under a 3X00 retainer. The pressure will not be that high. But an LS6 spring will be farily high. Probabally not required by any streetable cam you would select.

Yes.

[Froggx]

Just a note on price, I paid $5.19 each for my LS2/6 springs and at that price I don't figure cost to be much of an issue comparing these vs LS1 springs. Of course this is from GM Parts Direct which basically gives everyone outside the U.S. a 1 fingered salute so the argument is likely much more valid with you.

[RacerX11]

Just a note on price, I paid $5.19 each for my LS2/6 springs and at that price I don't figure cost to be much of an issue comparing these vs LS1 springs.

The LS1 springs are only $1.33 each through GMPD, so if you are on a tight budget it could make a difference.

Marty

[v6h.o.]

LS6 springs are 15$ Canadian$, compared to $3something for LS1's. (again Cdn funds)

How much did you pay on shipping of those springs from GMPD though?

[Froggx]

Shipping price was $12.46 for those, which I thought was perfectly reasonable, especially after it cost me more than that to ship 6 injectors cross country. I can see where it makes sense to go for the LS1 springs in Canada since it saves around $114 cdn before shipping. Price difference for Americans through gmpd is $46.32 which I guess makes sense if you're on a budget as well. At the time I was buying the consensus sounded to be that the LS1 springs probably wouldn't provide the pressures needed for 7000 rpm and beyond, but of course changes in installed height and their effects were basically ignored when that arguement was made.

[v6h.o.]

wow thats actually not a bad price from GMPD, I always hear horror stories of how people are missing and arm and a leg from the shipping bill from that place.

I can myself get the springs from GM cheaper than that price, But thats the full retail price on both setups from GM here.

[Froggx]

Both my rates from GMPD have been pretty good from when I've used them. My UIM from a 3500 was a little less than 20 if I remember.