Capt'n Two Rotors

Just got an 847 and 987 springs. Will the stock rockers hold until I can get rollers. Does any one know the max lift on them? I know its not right but will it work?

bunker

Should be fine, just keep the RPM below 6k to be safe.

Capt'n Two Rotors

it goes to 6300 now with the stock cam, but i guess the extra lift would be the killer?

30696bird

I'm using the stock with the cc306..........I spin it to 6500.

Capt'n Two Rotors

cool thank you very much, now I can sleep a little better.

disco192

i ran my stock headed 306 cam motor to 6500 rpm and it put down 348 rwhp with stock rockers...

Not too shabby if you ask me.

Capt'n Two Rotors

Does anyone have a max lift # for the stock rockers, I know the old SBC stockers would only go to around .450 unless you had long slots. Thanks for the input guys I'm just wondering if the little extra lift the 847 has over the 847 will get me into trouble

disco192

i ran mine to 540, i think stock is over 450 anyway. I wouldnt worry about the rockers with a 847 cam. You will lose power in friction and rocker flex, but I doubt that it will break a rocker unless you are goin with some SERIOUS springs.

Capt'n Two Rotors

Are the 987's SERIOUS?

disco192

meh... i would go with 918s.

Capt'n Two Rotors

I already bought the 987's though what would make you want the 918's over the 987's

disco192

they are easier on valvetrain parts and hold RPM better. I think the 987s shouldnt be too much of a problem. I guess you live and learn. I cant really say.

Capt'n Two Rotors

ok well lesson learned, I'll try em and see, I can't spin up too high cuz I'm still on the stock bottom end but hopefullly they will work up to 6500

disco192

i ran my stock bottom end to 6900 on a regular basis... but then again, i did blow a piston, snapped 2 rods, put a hole in my block as big as my fist, destroyed my LE2 heads, and took a chunk out of my cam.

But there were other issues than just the SB limits.

Capt'n Two Rotors

Thanks for the replys Disco. I just looked up the 918 and they are almost indentical in specs to the 987's,besides being duals and singles. The 987 have aboiut 8lbs more open and on the saet they also have 30# more on spring rate. The only advantage to the 918 that I can see is increased lift capability .715 to the 987's .600 . I think the 987 would hold RPM's better due to incresed open pressures and spring rate. And the 847 come in @ .595 with 1.6's when I get them so I think I have the right spring. Anyone else got any input?