S CAMS

Durring a valve adjust I noticed I did'nt have a spray bar on the left cam carrier. I started checking lobes and found damage. So, pulled the cam and surprisingly #1 intake was the only lobe affected. I took the (cams) to a local grinder who sugested instead of hard welding, just regrind the lobe to factory specs by lowering the base cicle. The only change would be the angle the rocker arm rests on the lobe. Now I can't get the cam to dial in, I'm hitting a piston. Is this result from lowering the base cicle? Any sugestions would be greatly appriciated.

Well, if your cam grinder did precisely what he said he was going to do, I don't think you would have a problem now. I can't imagine how you would have a clearance problem, unless the grinder made an error of MORE than 0.060" ... because there is usually that much 'safety' factor with 'S' cams and pistons! Of course, if you have the cam mis-aligned, that could explain the problem, too!

My suggesation is to check the cam timing using cylinder #2 or #3, since those were 'presumably correct when your engine left the factory! Just back the adjuster swivel-foot off all the way on cyl. #1 for now, and check the overlap intake lift for #2 or #3, then #1 again, to see if you made an error indexing the cam before tighening the 46 mm nut. Your 'error,' if there was one, would be much easier to fix than one by the cam grinder ... at this point!

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Warren Hall
1973 911S Targa

[This message has been edited by Early_S_Man (edited 05-18-2000).]

Thanks for the info Warren. I'll try this out and let you know what happens.

WARREN,
I was using a metric dial indicator and did'nt notice. Big time amature mistake! I reset everything and this time no problems. Thanks again for your help and I'll buy anything you publish.

Me too. Autographed.

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'83 SC

Don, No big deal, because you caught it before it made one of those expensive noises, like ... 'Whump' ... then DEAD SILENCE !!!

That would have been a 'big time' mistake ...

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Warren Hall
1973 911S Targa