[Dave_Rivera]

In my new 383, I was wondering what was the max safe cam lift. I figured that with a Comp Cams XE284 and 1.6 rockers, the lift @ valve should be around 540 on both sides. Is this safe???
Combo:
Flat top forged pistons (11 to 1 comp)
Balanced and Blueprinted
Dart Iron Eagle 180 closed chambered heads (I know they're too small)
Springs are good to 600 lift
Comp Cams Magnum roller tip rockers (1.6 ratio)
Holley 750 DP
Performer RPM AirGap

[Silver69Camaro]

There really isn't a way to find out, it depends on every engine. Factors like valve size, cam lobe design, piston design, deck height, etc. all play a role. But it isn't the max lift that causes problems, as interference usually happens between 0 and 20* ATDC.

I'm in the same boat. I'm moving up to a .600" lift roller cam with a 2.08 valve on my new heads. It's a Herbert cam, and they said if I check the clearance and its not enough, I can return the cam. You just wont know until you dial it in.

Ask Comp if you can return the cam if you find it wont work out.

[camp07]

hey dave rivera...i like the little quote at the bottom of your post!!

[Eric68]

Depends on the rods a lot too -- not just the cam.

Generally speaking, the longer the rod the tighter the clearances between the cam and rod get. Most aftermarket rods are designed with strokers in mind so you will probably have more clearance with an aftermarket rod. Capscrew rods will offer even more clearance.

Whatever you do just make sure you get in there and measure. I use a coat hanger flattened to .050" on the end as a go/no-go gauge.

[67RS502]

max safe cam lift
Piston to valve clearance is what youre askin about right?
It depends on duration of the cam and degreeing it, for the most part.