I have a couple lifters that are starting to tick so I am thinking on doing a cam swap while I'm at it. Basic setup, stock 350 vortec, holley 650, carb spacer, dual plane vortec intake, flat top pistons with a 700r4. What I want is obviously something that's going to maximize my torque and hp but also it has to be street driveable. Not racing, just a daily driver. I don't want to get into any mods, just want to slide a new cam into this engine for cheap. BUT, I need some advice as to what i would be looking for.

 

In the last couple of months, there's a really good article in Super Chevy. I think they used a Comp Cams XE268HR 224/230 @ .050....but don't hold to those numbers.

Good Luck

 

On the cheap? Might look for a LT4 hotcam. Heck, run it on 1.5 rockers to save a few more bucks. The vortecs won't care!

 

Picking up a cheap used LT4 Hotcam is certainly a good option. Degree it in at 105-106 ICL rather than the 109 "drop-in" ICL, and you won't get the "lack of low end" that sometimes gives it a bad name. And it will still pull to about a 6000 rpm power peak with your intake.
What's your present cam and valvespring setup?
What's your static CR?
What torque converter?
What rearend ratio?
What vehicle weight?

 

Rv cam in it now, stock valve train, 3.42 rear end, 4000lb car, stock converter not sure about the stall. What is static cr?

 

I'm thinking of a crate Vortec 350 and swapping in a stock TPI cam in it and using my TBI system. Maybe have to put a lil stronger fuel pump and bump up pressure some but easy swap and should be a good strong cruiser hopefully I can get a good mail order tune I do not want to get into all that. Or I could revert to Carbed like I always have and build a much livelier engine and probably tear up some more rear ends and such as I have in the past.. lol

 

I tried the tbi mail order too. 4 chips later, I ended up putting a carb on it.

 

Wow, that's a heavy car. 3rd Gen?
I wouldn't even be thinking about a cam swap until you're willing to upgrade the TC. Any cam similar to the Hotcam or above-mentioned XE268 should get at least a 9.5" 2800 stall TC for decent response on take-off.
CR = compression ratio.

 

The 268 is a flat tappet cam, you have a roller block and in no way should you use anything else. That being said the XR270HR is a great cam for what you wan

http://www.compcams.com/Company/CC/c...?csid=158&sb=2

I helped a friend build his mild 350 with a 264HR that is a great cam makes power from about idle to 5500 and is a little more mild if that is what you wan't

http://www.compcams.com/Company/CC/c...?csid=157&sb=2

 

Here are some factory dynos of comp cams to give you n idea of power bands

http://www.compcams.com/Pages/401/dyno-sheets.aspx

 

Static Compression Ratio (CR) is the ratio of the cylinder volume with the piston at the bottom verses piston at the top. Add up:
+ unused cylinder at top of the bore (how far is the piston down in the hole)
+ head gasket
+ chamber
+ piston relief (- piston pop up for non-flat tops)
Compare that number against the same number added to the cylinder bore.

For a typical L31 Vortex 350, those numbers are:
0.025" in the hole (0.025" x 4" bore/2 x 4"bore/2 x 3.14) = 0.3142ci = 5.15cc
0.046" gasket (0.026" is a better choice w/ 0.025" in the hole) = 0.578ci = 3.5cc
64cc is the typical Vortec head chamber
7cc is the right ballpark for 2 or 4 valve relief piston
The piston sweeps through: 3.48" stroke x 4" bore = 43.73ci (1/8 of 350ci) = 716cc.

Either add all those up and finish the math, or plug into an online calculator, and you get 9.36:1. (or 9.78:1 with the 0.026" head gasket)... notice how much just a 20 thousandths difference in head gasket thickness affects the CR. This is pronounced "9.36 to one", and means 9.36 units get compressed into one.

Dynamic CR takes into account that pressure doesn't start building until the intake valve closes, which is some number of degrees After Bottom Dead Center (A BDC). This is why your cam timing is related to choosing a proper CR for your engine. Target dynamic CR for a street engine and pump gas is 8.0-8.5 to 1. This is the more detailed way to get to the rule of thumb that 9.0:1 to 10.0:1 static CR is a good pump gas ratio... depending on the cam chosen.

If you put a race cam (240* or more @ 0.050") into a 9.36:1 engine, it will be a dog, because the intake valve closes so late, it can't build much pressure.

Conversely, if you put a mild street cam (210* or less @ 0.050") into a 10.0:1 engine, it will ping like crazy, because the intake valve closes while the piston is closer to the bottom of the cylinder, and builds more pressure than the pump gas octane can handle.