GM High Tech Performance
Click here to find out more!

cam shaft lsa

  
GM High-Tech Performance
Item Posts    Sort Order

cam shaft lsa

 
Red2N Red2N
New User | Posts: 33 | Joined: 04/12
Posted: 07/08/12
06:57 AM

question...i currently have an LT4 hotcam, with 1.6 magnum rockers. the hotcam has a factory lsa of 112 degrees. I did a little reading about lsa's on this site and my question is, to give my lt1 more Power  and torque, would a cam grind with the same sPecs but a wider(107 or 110 degree)lsa allow me to meet my goal? can this be done while maintaining daily driver esq street manners?  

Scott Parker Scott Parker
Moderator | Posts: 215 | Joined: 12/07
Posted: 07/09/12
10:57 AM

That would depend largely on the rest of your combination. However, camshaft design has improved significantly since the creation of the GM Performance Parts LT4 Hot Cam. Here are a few to consider:

Elliotsportworks.com

Elliots makes a cam comparable to the hot cam, same street manners, with updated lobe profiles. This cam specs 218/224 duration, .570/.565-inch lift, 111 LSA with an operating range of 1500-6000 RPM. However, Elliots also says its next step up has a mild idle that will work with factory gears and converter, while even being clean enough to pass emissions in some states. This cam is a 224/230 duration with 573/.568-inch lift and 112 LSA (1700-6100 RPM).

Comp Cams

In Comp's XFI line you can choose between the Xtreme Fuel Injection 07-466-8 (218/224, .570/.565, 113LSA or the Xtreme Energy 07-305-8 (220/230, .510/.510, 114LSA). In this case, you can see how the LSA is used to help maintain idle quality and street manners with increased duration. The latter is a revised version of the classic CC305 cam and would be a more substantial improvement over the current LT4 hot cam.


My preference would be for the larger of either grind since you are going through the trouble of changing out the camshaft, only a moderate improvement might be a disappointment given the time and money spent. And those camshafts are still small enough that you don't have to worry about poor idle quality and other issues that can make your car miserable to drive.  

Red2N Red2N
New User | Posts: 33 | Joined: 04/12
Posted: 07/12/12
05:56 PM

Thanks for the update Scott. I'm almost at the point of buying the upgraded cam from comp actually. What I am now unsure of is whether or not I will have to upgrade the valve springs that came with the hot cam. The thing is, I've tried to find out if the springs are capable of standing up to the future comp piece, but all I've been able to find is the .525/.525 rating and not the spring's max lift rating.  

pepsi1 pepsi1
User | Posts: 111 | Joined: 09/11
Posted: 07/12/12
06:58 PM

If you go into Jeg's web site and look at the K-Motion specs for the stock valve spring diameter you can choose a good valve spring. Unless you intend to open the valve seat diamater.

Just some FYI. I don't know what heads you are using just remember to check your valve spring retainer to valve guide, and seal clearance, when you install a higher lift cam. Also check the valve spring geometry.  

Red2N Red2N
New User | Posts: 33 | Joined: 04/12
Posted: 07/13/12
12:35 PM

I am using the stock heads, with the stock valve diameter. the only thing that has been ported is the intake runner. the cam calls for use with the beehive springs. i am in the dark as far as which to pick because I know absolutely zilcho about vavle springs.  

Scott Parker Scott Parker
Moderator | Posts: 215 | Joined: 12/07
Posted: 07/19/12
07:23 AM

Valvesprings are a wear item, so it never hurts (except in the wallet) to change them out...especially if you are unsure.  

Red2N Red2N
New User | Posts: 33 | Joined: 04/12
Posted: 07/27/12
06:39 AM

I have the XFI 230/236 576/571@.050 duration part number 07-467-8. my question is do i need to use larger valves than stock to get good performance out of this cam? I have the retainers and the beehive valve springs too  

Red2N Red2N
New User | Posts: 33 | Joined: 04/12
Posted: 08/01/12
07:22 AM

would I need to upgrade my lifters and pushrods as well?  

Scott Parker Scott Parker
Moderator | Posts: 215 | Joined: 12/07
Posted: 08/02/12
10:17 AM

You definitely should not use stock pushrods, and lifters are a good idea as well.