new cams-new rockers????

HI ALL,I'M UPGRADING MY 3.0SC WITH A SET OF WEBCAMS CSI GRIND CAMS.MY QUESTION FOR EVERYONE IS DO I NEED NEW ROCKERS????? ONLY 55K ON MOTOR,2%-3% LEAKDOWN,SO ALL INDICATIONS SAY VERY LITTLE WEAR ON THIS MOTOR.I'D RATHER SPEND THE $$$ ON OTHER UPGRADES,THANKS FOR YOUR HELP ,HANK...

Hank,

No, you don't need new rockers, but be sure to check the shafts and bushings for wear ... the rockers can be rebushed if necessary.

You are going to get a valve job done on the headsw, right?

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Warren Hall
1973 911S Targa

Can't imagine why you'd need new rockers, but one thing to be sure to do is rotate the rocker shafts 180 degrees when you reinstall them, so that the rockers are "wearing" agains the fresh side of the shafts. You can see see where the rockers have been polishing the metal with their back-and-forth motion, just reinstall the shafts with that part of the shaft facing away from the head.

Stephan Wilkinson

Rockers need to refinished/refurbished before
putting them against a new cam. The
lift edge need to be flattened. Most
machine shops will do this for
a nominial cost. A new cam can be
influenced (damaged) by pre-existing wear
surfaces of the rockers arms.

The bushings, of course, need to be
checked and replaced as needed. Check your
rocker pins for wear as well.

Bill

HI WARREN,YES I'M DOING A VALVE JOB ALONG WITH THE CAMS.I'M ALSO DOING THE RINGS AND WILL PROBABLY REPLACE THE VALVE SPRINGS AS PART OF THE VALVE JOB.THE WEB CAMS I'M USING PULL TO ABOUT 7500 RPM,BUT I PLAN ON LIMITING IT TO ABOUT 7000 RPM.I HAVE A 78 EURO DISTRIBUTOR AVAILIBLE BUT AM CONSIDERING CRANK FIRE,ANY COMMENTS?THE PACKAGE WILL BE COMPLETED WITH SSI'S AND DANSK MUFFLER.IT'S A 83 TARGA,ALSO LOWERING TO EURO SPEC,21-27mm TORTION AND SPORT SHOCKS.

Hank,

Unless you are doing a dual-plug conversion on the heads, I see no reason to even consider the expense of crank-fire system! The euro distributor should work fine ... just put a Bosch # 1.234.332.206 rotor in it and you will be limited to 7300 rpm.

Sounds like a great cam, no reason to limit the fun to 7000! Close to a GE-60 grind, or 964?

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Warren Hall
1973 911S Targa

HI WARREN.THANKS FOR THE INFO,REGARDING THE GRIND FOR THE NEW CAMS ITS .485 IN & .452 EX LIFT WITH DURATION OF 238DEG IN AND 226DEG EX ,WEBS GRIND 20/21 SPEC.WEBCAM DOES THIS GRIND JUST FOR THE CSI SET UP.THE EURO DISTRIBUTOR IS THE ONLY MOD NEEDED,LONGER CURVE.I'D LOVE TO FIND A 78-79 FUEL INJ SET UP FOR THE BIGGER RUNNERS,WE'LL SEE WHAT HAPPENS IN THE NEXT FEW WEEKS! THANKS AGAIN,I LOVE THIS FORUM.

Hank,

Those sound like 'improved' 964 cams with same duration and 0.021" Intake, and 0.027" Exhaust ... more lift. Sounds like it's going to be a great 3.0 engine to me!

Have you thought about putting a 7:31 ring & pinion gearset in your 915 transaxle? It would really improve your acceleration in all five gears and with a higher-revving engine, the top speed would hardly be affected at all!

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Warren Hall
1973 911S Targa

HI WARREN.I'M THINKING ABOUT THE QUICKER RING N PINION BUT I'M NOT SURE IF IT'S IN THE BUDGET AT THIS TIME.I'VE ALSO GOT A SET OF SPORT BILSTIENS AND 21mm & 27mm T-BARS GOING IN.THE INJECTION SYSTEM WOULD PROBABLY COME FIRST BUT YA NEVER KNOW.AND WITH LIVING IN NEW ENGLAND,NEXT YEARS GARAGE SEASON IS NEVER THAT FAR OFF!!!THANKS AGAIN FOR THE COMMENTS,WITH THE LOW MILES ON THE MOTOR AND IT'S OVERALL CONDITION I THOUGHT THE ROCKERS & SHAFTS WILL BE FINE,BUT IT'S ALWAYS NICE TO GET A FEW OTHER OPINIONS. HANK911

Hank,
I was wondering if you could give me an estimate of what the cams cost and the hours of labor to install them? I am cosidering similar options on my 1982 SC with weber 46 IDA carbs. Thanks

COST ON THE "REGRINDS" IS ABOUT $650 WITH YOUR CORES.i'M DOING THE TOP END,VALVE JOB AND SOME BOATAILING WHILE ITS ALL DOWN.I/M GUESSING IF YOU JUST "DO" THE CAMS IT'S ABOUT A 10-15HOUR JOB,WITH YOU PULLING THE MOTOR,MAYBE SOMEBODY COULD GIVE US A MORE ACCURATE ESTIMATE. GOOD LUCK!!