So I'm having my engine rebuilt and I'm considering bumping up the cam just a little bit to get a little extra kick. My builder has recommended going with the stock LT4 cam (not hotcam). Now I'm not looking to put down some real serious numbers here, I'm just looking for a little bit more kick. I realize that going a bit bigger to say a 227 or a cc305 would give me more, but how much could I expect to see if I went with this cam? Also has anyone on here tried this before?

btw: Mods include Pacesetter mids, Flowmaster catback, and a K&N intake

 

If looking to stay super mild and GM consider the ZZ4 crate motor cam. DIRT cheap, real easy on parts, end may need to be opened up a little for the opti but he should be able to handle that. Probably a whole lot cheaper and easier to find than a stock LT4 cam.

 

The stock LT4 cam has a very small increase in duration compared to an LT1. Like 3 degrees. I'd call it not noticeable. The cam phasing intake to exhaust allowed the LT4 to come factory with no EGR. Also not a big benefit. The increase in lift numbers is mostly due to the 1.6 roller rockers as opposed to the 1.5 ratio stamped rockers on the lt1. Without changing the rockers, I'd almost call it 3-4 hp on a 300hp engine. The air temp will make more difference than this cam swap. Here is a link to some specs.

http://www.grandsportregistry.com/lt1vslt4.htm

 

Please don't shoot yourself in the foot by wasting money on a LT4 stock cam. It's barely bigger at all. Throw in a Hotcam, XE502, or CC305, GM846 and have some fun with the car.

-Dustin-

 

I don't want to hijack this thread, but what sort of gains can be expected from the ZZ4 cam? The reason I ask is that I have one laying around that I took out of my ZZ4, and was thinking of tossing it in my 93. I have a set of hotcam springs and retainers from a hotcam kit too. Any thoughts?

 

couldnt you just put the lt4 hotcam in, and use 1.5 rocker arms.. that would put you around stock lt4 territory, then if you wanted more you could put on 1.6rocker arms later on..

 

Go with the lt4 hot cam kit, you should be happy with that. You will not be so happy with the stock cam lt4 cam.

 

the zz4 cam isnt far off from a lt4 hotcam.. spec for the zz4 is given with 1.5 rocker arms.. specs for hot is given with 1.6 rocker arms..

heres from gm's parts list:
part# 10185071
This hydraulic roller tappet is used on the 5.7-liter H.O. 350 ZZ3 & 4 engines. The duration at lash point in degrees (intake/exhaust) is 275/280; duration at .050" tappet lift (intake/exhaust) is 208/221; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 474/501. Valve lash is zero/zero and lobe centerline is 112 degrees.

lt4 hotcam:
part# 24502586
The duration at lash point in degrees (intake/exhaust) is 279/287; duration at .050" tappet lift (intake/exhaust) is 218/228; and maximum lift with 1.6 rocker ratio (intake/exhaust) is 525/525. Valve lash is zero/zero and lobe centerline is 112 degrees.

if running 1.6 rockerarms on the zz4 cam it would have a little better bottom end probably...lt4 hotcam would have a better topend.. zz4 cam would probably fall off after about 5800rpms though..

think i would go with the hotcam..

 

Thanks for all of the imput and advice. I've decided to bump up to a CC304 rather than go with the stock LT4 cam. I'll let you know what I think of it when I get the car back.

 

I would strongly discourage you from using one of the 114LSA NA cams like that.

If you do go that route at least try and get it ground on a 110-112LSA will still be mellow but not as badly compromised.