After market cam with stock springs?

[SS 376]

OP, maybe LS1Tech if you're looking for more substantive responses.

As I recall, the ADM Stage 1 cam is a lot like the LS9 cam-might even be the same cam. I also seem to recall that the Lingenfelter GT-11 is like the LS9 too.

I would also talk to Comp cams for a custom grind. It'll be more than the LS9, which is what, $125, but they can grind something that will work with the stock valvetrain.

I would also talk to some of the better known cam makers like Vengeance and Thunder Racing. I think some of their most mild cams might work on the stock valvetrain. I feel like Thunder definitely had something for the stock valvetrain.

[Irnwkrkev]

GT-11 has HUGE lift but low duration. You can't get away with anything but double springs for that cam.

[Bad70supreme]

Thanks for the replies, I will contact some of those comapanys before I decide. Thanks

[flht99b]

I'm interested in this too as I am considering the LS9 cam, doing all the work myself and was wondering what would be a good, reliable set of springs for the LS9 cam for a daily driver with an occasional road course or autocross event.
Ed M.

[Bad70supreme]

LS9 cam works with stock valve train parts and stock tune...thats the only reason to run it! If you plan on new springs, you might as well run a true aftermarket cam.

[caper]

How hard would this install be, seems like a good idea to me too.

[JM10]

Originally Posted by caper

How hard would this install be, seems like a good idea to me too.

Dumb Question:

What do you have to remove or do to install the LS9 cam on a SC engine?

JM

[Bell040]

I have been interested in this for several months. I have done a ton of research on this subject and found out that some peolpe don't know what they are talking about. I guess they are trained that you need to upgrade everything they can (or add "insurance")... whenever they can, no matter the cost.

The LS3 uses the springs from the LS6/LS2. GM part # 12586484 has been used on the LS2/LS6/LS3 since February of 2004.

http://forums.corvetteforum.com/c5-z...-spring-3.html

https://store.gmperformanceparts.com...umber=12586484

They are good to .570" lift. Aftermarket springs will get you up to .600, 650, and even .690" depending on the style. Therefore, for any cam with less than .570" lift, you can (and probably should) reuse the springs, seals, seats, and retainers. You will save yourself alot of money and headache. Remember that the factory installs things with precision, gearheads usually do not.

EDIT: Also, stock LS7 valves and springs are ok to use for .570” thru .591” lift

However, you should use new pushrods if the new cam has a smaller base circle than stock (most of them do) or you will have "valve float" if the pushrods are too long or lifter ticking if they are too short. There is a tool that you can use to determine the size of the pushrods needed. Or... the most direct method for determining the pushrod size is:

EDIT: see post #87 of the camshaft DIY thread for replacement pushrod length calculation for an LS3 http://www.camaro5.com/forums/showthread.php?t=125123

Most people that measure the required length with the special tool also use this method to make sure the measurement is in the right ballpark. When it is time to order the pushrods, 16 of these (0.080" wall thickness) cost $100 - $150. You will be removing the pushrods anyways to get the lifters up, so no biggie.

After reading a horror story of a guy that stayed with a single bolt cam (timing gear pin broke, crank was spinning, cam was not ... )... I would go with a 3 bolt design. You will need GM part # 12586481 (timing gear) to do the conversion. You will hear from multiple sources that the stock tensoner will not work with a 3 bolt cam... but the guys at the factory that make the LS9 think otherwise and call it an upgrade over the LS2 dampener.

http://jalopnik.com/#!5371569/how-we...a-corvette-zr1 and http://www.gm.com/experience/technol...LS3_Marine.pdf


Overall, I think your best bet is to get a custom grind cam that has ~.565"-.570" lift, then let the pros determine the LSA and duration (which determines overlap) per your drivability needs, and request that the cam have the same base circle as stock. Then you can just pull the old cam out... and put the new one back in (you may want new gaskets).

I have an excel sheet that I am using in preparation to buy parts, tools, gaskets, etc. My cost would be ~$570 for a cam with less than 0.570" lift and a stock base circle. It will be $947 for one that is more than .570" and a smaller base circle (these do not include the timing chain or the tune). Strangly enough there is a shop in texas that will do the whole ordeal (parts and labor) for $1000... http://www.camaro5.com/forums/showthread.php?t=117934 ... for a cam with over .600" lift ... I'm not sure how they pull it off.

Please reference the cam DIY: http://www.camaro5.com/forums/showthread.php?t=125123, but you will get to skip a bunch of difficult steps since you are using the stock valvetrain and timing chain.


...I am not a mechanic... nor do I work at a performance shop, but I am pretty good at doing my homework. I hope this helps.

[flht99b]

Couple of questions. Is anyone running the LS9 cam in a N/A LS3 ?? If so, does it idle close to stock ?? Does the LS9 cam have the same base circle dimension as the stock LS3 cam ?? What valve springs did you use on the LS9 cam ??
TIA...Ed M.

[NinoSS]

Originally Posted by Bell040

I have been interested in this for several months. I have done a ton of research on this subject and found out that some peolpe don't know what they are talking about. I guess they are trained that you need to upgrade everything they can... whenever they can, no matter the cost.

The LS3 uses the springs from the LS6/LS2. GM part # 12586484 has been used on the LS2/LS6/LS3 since February of 2004.

http://forums.corvetteforum.com/c5-z...-spring-3.html

https://store.gmperformanceparts.com...umber=12586484

They are good to .570" lift. Aftermarket springs will get you up to .600, 650, and even .690" depending on the style. Therefore, for any cam with less than .570" lift, you can (and probably should) reuse the springs, seals, seats, and retainers. You will save yourself alot of money and headache.

EDIT: Also, stock LS7 valves and springs are ok to use for .570” thru .591” lift

However, you should use new pushrods if the new cam has a smaller base circle than stock (most of them do). There is a tool that you can use to determine the size of the pushrods needed. Or... the most direct method for determining the pushrod size is taking the stock base circle diameter (D1), subtract the new base circle (D2) divided by 2 (to get radius). Then add this number (delta L) to the stock pushrod length (L1 = 7.325") and find a pushrod that is as close as possible to this new number (L2). Most people that measure the required length with the special tool also use this method to make sure the measurement is in the right ballpark... [(D2-D1)/2]= "delta L"... and L1 + "delta L" = L2 = new pushrod length. 16 of these (0.080" wall thickness) pushrods cost $100 - $150. You will be removing the pushrods anyways to get the lifters up, so no biggie.

After reading a horror story of a guy that stayed with a single bolt cam (timing gear pin broke, crank was spinning, cam was not ... )... I would go with a 3 bolt design. You will need GM part # 12586481 (timing gear) to do the conversion. You will hear from multiple sources that the stock tensoner will not work with a 3 bolt cam... but the guys at the factory that make the LS9 think otherwise and call it an upgrade over the LS2 dampener.

http://jalopnik.com/#!5371569/how-we...a-corvette-zr1 and http://www.gm.com/experience/technol...LS3_Marine.pdf


Overall, I think your best bet is to get a custom grind cam that has ~.565"-.570" lift, then let the pros determine the LSA and duration (which determines overlap) per your drivability needs, and request that the cam have the same base circle as stock. Then you can just pull the old cam out... and put the new one back in (you may want new gaskets).

I have an excel sheet that I am using in preparation to buy parts, tools, gaskets, etc. My cost would be ~$570 for a cam with less than 0.570" lift and a stock base circle. It will be $947 for one that is more than .570" and a smaller base circle (these do not include the timing chain or the tune). Strangly enough there is a shop in texas that will do the whole ordeal (parts and labor) for $1000... http://www.camaro5.com/forums/showthread.php?t=117934 ... for a cam with over .600" lift ... I'm not sure how they pull it off.

Please reference the cam DIY: http://www.camaro5.com/forums/showthread.php?t=125123, but you will get to skip a bunch of difficult steps since you are using the stock valvetrain and timing chain.


...I am not a mechanic... nor do I work at a performance shop, but I am pretty good at doing my homework. I hope this helps.

Great post!

[Bell040]

Originally Posted by flht99b

Couple of questions. Is anyone running the LS9 cam in a N/A LS3 ?? If so, does it idle close to stock ?? Does the LS9 cam have the same base circle dimension as the stock LS3 cam ?? What valve springs did you use on the LS9 cam ??
TIA...Ed M.

Go to "search", choose "advanced search options", type "LS9 cam", choose "search only thread titles"... then hit search.

It pulls up a few people selling them among all of the technical threads... but you will have plenty to read.

[rvadim76]

Originally Posted by flht99b

Couple of questions. Is anyone running the LS9 cam in a N/A LS3 ?? If so, does it idle close to stock ?? Does the LS9 cam have the same base circle dimension as the stock LS3 cam ?? What valve springs did you use on the LS9 cam ??
TIA...Ed M.

To give you a heads up:
yes some people (including myself) are running this cam on LS3 n/a engines. Idle is even smoother than stock. LS3 and LS9 cams have the same base circle. LS9 can be (maybe should be) used with the stock springs (one of the reasons most people doing this swap).
I personally plan on going FI route that's why I am doing the swap (in progress). It's also a relatively good (some may say "not good") power gain over the stock ls3 cam for n/a engines and the swap is easy to do (needless to say it is cheap).

[rvadim76]

Just realized this thread is not active anymore )) for like 5 years )) hopefully this will prevent posting similar questions.

Have a great week Everyone!