Can I get a list of everything I need to assemble my L92 heads?
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01-12-2009, 10:04 PM
#8
I'm doing the exact same swap as you are right now(L92 heads/aftermarket cam)Yes you should absolutely shim your valve springs!!! I have also thought a lot about what else to do.
Here is what I'm doing, I went with the GM L92 head gaskets and exhaust gasket. Also buy the replacement dampener bolt.
I'm going with Comp Cams new LSR cam, 219/227 .610ish lift on a 112.(seems to be in between an XER and LSK Lobe)
I just received my LS3 intake valves today!!! (#12569427) and they look really nice. I weighed them against my new L92 valves and there is a 19g difference(106.6g vs 87.6)!!! They are truly worth the money! I'm going to put up a thread showing them side by side soon too just for everyone to see. Being light weight on the spring, retainer, and valve plays a huge role in valve train stability and also durability. An out of control valve train breaks parts, one thats in control will last a long time.
https://ls1tech.com/forums/generatio...l#post10836332
I'm replacing the lifters while I'm at it, not because they are bad, but because I'm going to have the heads off anyways. (Comp #850-16)
I already have 26918 springs, the new silver ones. I will measure each one and install it .060" from coil bind. You really need to take the time to setup your springs well. Ive seen a lot of data, and you can run tighter than .060 and it can help or hurt depending on the entire valve train system, but .060" is safe and consistant.
I'm using stock valve locks and stock retainers, I could go lighter with Ti retainers but mine will be driven on the street and Ti will wear away. Plus stock retainers are only ~11g and Ti are ~6g. I'm giving up a few grams for durability here. I also have .105" wall hardened push rods, because you want the back side of the system as stiff as possible, weight is much less of a concern on the lifter and push rod. Stiffness is key until you really start "racing" then you worry a bit more about mass on that side of the rocker arm.
I'm also sticking with the stock rocker arms for now, they are a very nice piece.
Last edited by SweetS10V8; 01-12-2009 at 10:44 PM.
01-12-2009, 10:32 PM
#9
I already have 26918 springs, the new silver ones. I will measure each one and install it .060" from coil bind. You really need to take the time to setup your springs well. Ive seen a lot of data, and you can run tighter than .060 and it can help or hurt depending on the entire valve train system, but .060" is safe and consistant.
Just as a point of reference, I've had titanium retainers on my daily driver for the last 60,000 miles and have not had any significant retainer wear. They will wear, but not at a significant rate unless the spring ends are not prepped correctly.
01-12-2009, 10:39 PM
#10
These cams use LSL lobes.
Can you weigh these springs?
Just as a point of reference, I've had titanium retainers on my daily driver for the last 60,000 miles and have not had any significant retainer wear. They will wear, but not at a significant rate unless the spring ends are not prepped correctly.
Can you weigh these springs?
Just as a point of reference, I've had titanium retainers on my daily driver for the last 60,000 miles and have not had any significant retainer wear. They will wear, but not at a significant rate unless the spring ends are not prepped correctly.
I truely thought for a long time about Ti-retainers also. But then I came to the realization that my 11g retainer would be unheard of not too long ago, lighter than many Ti retainers for non behive springs (im assuming). Plus it makes my wife happier keeping the money in the bank. I have to reassure myself I made the best desicion, plus retainers are easy to change!
01-12-2009, 10:58 PM
#11
Thanks.
I'm not criticizing your decision, just stating that titanium is more than safe from wear related issues on a daily driver. From a pure money stand point, the stock retainers are a better option.
I would recommend using some nice machined chromemoly locks. For approximately $30 it's a a no brainer.
I truely thought for a long time about Ti-retainers also. But then I came to the realization that my 11g retainer would be unheard of not too long ago, lighter than many Ti retainers for non behive springs (im assuming). Plus it makes my wife happier keeping the money in the bank. I have to reassure myself I made the best desicion, plus retainers are easy to change!
I would recommend using some nice machined chromemoly locks. For approximately $30 it's a a no brainer.
01-13-2009, 08:52 AM
#13
Im just going to put stock L92 valves in these heads with some 918 springs or som pac-1218's. Would I still need to be shimming? How do I know if I should shim them or not? I guess I need a step by step procedure. Im from the sbc world so the LS engines are very new to me.
01-13-2009, 07:27 PM
#15
Im just going to put stock L92 valves in these heads with some 918 springs or som pac-1218's. Would I still need to be shimming? How do I know if I should shim them or not? I guess I need a step by step procedure. Im from the sbc world so the LS engines are very new to me.
Heres how you do it;
Step one, measuring the springs
Take every spring individually, squeeze it until it coilbinds.(see pic below) For example lets say this one coilbinds at 1.100". Dont go off what the box says, measure it.
2.Add .060", this sets us at our predetermined ".060" away from coilbind height.
3. Add the lift of your camshaft. Say, .615" for our example.
4. Add the previous three numbers, 1.100+.060+.615 = 1.775". This is the installed height this individual spring needs to be installed at. I personally label them and put them in individual ziplock bags to keep them in order.
Step two, Measuring installed height
1. Measure each individual valves installed height by using and installed height checker (see pic below)which measures the distance between the spring seat and the retainers.
Using our example lets say we measure 1.790". Now we match the valve spring that has the close intalled height spec from step one. Our example needs to be installed at 1.775". So we take the valves measured installed height(1.790") and subtract the springs needed installed height(1.775"). So we get 1.790"-1.775" = .015". This is the amount of shim needed, so you take off your spring seat and install a .015" spring shim underneath it and install the spring.
Last edited by SweetS10V8; 01-13-2009 at 07:43 PM.
01-14-2009, 12:17 AM
#17
Every engine need its valvespring shimmed correctly, its just that not everyone used to do it. Typically people used to install springs to certain installed height and just let it roll, for example "I installed all my springs at 1.800". Information is much easier to obtain now and everyone is getting smarter.
Heres how you do it;
Take every spring individually, squeeze it until it coilbinds.(see pic below) For example lets say this one coilbinds at 1.100". Dont go off what the box says, measure it.
2.Add .060", this sets us at our predetermined ".060" away from coilbind height.
3. Add the lift of your camshaft. Say, .615" for our example.
4. Add the previous three numbers, 1.100+.060+.615 = 1.775". This is the installed height this individual spring needs to be installed at. I personally label them and put them in individual ziplock bags to keep them in order.
1. Measure each individual valves installed height by using and installed height checker (see pic below)which measures the distance between the spring seat and the retainers.
Using our example lets say we measure 1.790". Now we match the valve spring that has the close intalled height spec from step one. Our example needs to be installed at 1.775". So we take the valves measured installed height(1.790") and subtract the springs needed installed height(1.775"). So we get 1.790"-1.775" = .015". This is the amount of shim needed, so you take off your spring seat and install a .015" spring shim underneath it and install the spring.
Heres how you do it;
Step one, measuring the springs
Take every spring individually, squeeze it until it coilbinds.(see pic below) For example lets say this one coilbinds at 1.100". Dont go off what the box says, measure it.
2.Add .060", this sets us at our predetermined ".060" away from coilbind height.
3. Add the lift of your camshaft. Say, .615" for our example.
4. Add the previous three numbers, 1.100+.060+.615 = 1.775". This is the installed height this individual spring needs to be installed at. I personally label them and put them in individual ziplock bags to keep them in order.
Step two, Measuring installed height
1. Measure each individual valves installed height by using and installed height checker (see pic below)which measures the distance between the spring seat and the retainers.
Using our example lets say we measure 1.790". Now we match the valve spring that has the close intalled height spec from step one. Our example needs to be installed at 1.775". So we take the valves measured installed height(1.790") and subtract the springs needed installed height(1.775"). So we get 1.790"-1.775" = .015". This is the amount of shim needed, so you take off your spring seat and install a .015" spring shim underneath it and install the spring.
01-14-2009, 07:15 AM
#18
Every spring, aftermarket or not, should be properly installed! Sometimes it requires shims, sometimes they dont require anything, and other times you have to cut the spring pocket deeper to acheive the installed height you need. But all the L92 heads Ive done have typically needed shims on most of the time. I havent had to cut the pockets deeper as of yet.
The heads do not come with any shims. GM machines the heads to try to achieve a certain installed height + or - a few thousandths.
If you look at the picture of the cylinder head, at the very bottom of the picture you can see the valve seal and spring seat. They are integrated together on the new LS engines. You add shims underneath that.
Spring shims come in packs of individual sizes typically packs of 16ea (.015, .030, .060). What you need is a multi sized kit that comes with a variety of thicknesses like this;
http://store.summitracing.com/partde...5&autoview=sku
Last edited by SweetS10V8; 01-14-2009 at 07:23 AM.
