71 Buick 455 Max Cam Lift

I'm building a 71 Buick 455 and I would like to know the maximum lift cam that will work with stock valve train?? Any help would be appreciated.

 

Lot of variables but generally speaking 525 is the cutoff

 

If you don’t have pistons with valve reliefs and you don’t have over 10.5:1 then I wouldn’t be looking to max out the cam specs.

 

I agree with this if you have the 430/400 rockers........I put plenty of pushrod through and broke rockers arms at a tick over .500. If using stamp steel arms I would say under .500 as long as spring pressure are kept in check

 

If you don't have valve reliefs stay away from anything over .500" lift. Stock heads or even somewhat opened up(ported) heads really don't need much over .500" lift anyway. If you want to run stock steel rockers with higher lift try to run new ones. One of the biggest problems with trying to run heavily used factory installed rockers is the well worn-in pushrod cup and tip at the valve are now trying to run over areas that were never exposed to stress when the cam was only .400" lift. At .500" lift it would be running out of the "groove". As mentioned the spring pressure is a big factor.

 

Thanks for the info!!

 

Thanks a lot!!

Thank you very much for everyone's reply!! It was valuable information.

 

Also if you go over .510 lift you will need to have the guides cut down and install the Teflon seals to keep the retainers from hitting the guide at full lift.

 

Good stuff..
I have a TorqueTech Spx2 that has .512 lift with 1.6 rockers. I feel good about using it with 1.5 stock stamped (new) rockers if the compression ratio is acceptable after installing my new heads. Will cc heads and measure piston depth in hole, do the math etc. Thanks for the information gents!
JIM

 

That should not you .480ish with the smaller rockers.....should ve well within specs.


Ta stage1 plus spring are great for lifts in thus area. We ran them on our cam that had .525ish lift and stk rocker though we did break a few......when we switched cam to postons gs110. Just under .560 the spring worked well still and even ran then in a custom comp cam having .575 lift......

 

Good info. TY.
I'm using TA Stg1 Plus Springs, so again, good info. Newer stamped rockers on heavy duty shafts... Jim