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914World.com _ 914World Garage _ What is the most cost effective cam and rocker arm prep on rebuild?

Posted by: tornik550 Sep 19 2015, 09:36 AM

I am rebuild my /6 2.7l. Everything is either brand new or freshly machined except for the rocker arms and camshafts. I have E cans and I found that there is pitting on one lobe on one cam. I have already spent a fairly massive amount of money. I'm not interested in spending a launch more. I realize the importance of proper cam break in and such.

From what I can see, cam regrind is about $350-400 which I do not believe includes repairing the pitted lobe. Rocker arm reconditioning seems to be around $400. So I would be at somewhere over $800.

What are the most cost effective solutions for having my cam repaired, properly prepared (regrind...), and rocker arm refinishing?

Posted by: Mark Henry Sep 19 2015, 10:21 AM

The big cost on rockers is rebushing all of them, if they are in spec you don't have to do this. The contact area is what can wear, if they are worn you will definitely see/feel a wear ridge from were the pad rides on the cam lobe, then they must be reground. If they are totally in spec you can get away with polishing the contact patches.

I think you are just a tad low on the cam regrind price. I know it's expensive, but you've gone this far and the cams is not a place you want to cheap out on.

Posted by: toolguy Sep 19 2015, 12:27 PM

I was faced with the same high price for rocker regrinding. . after watching a U-tube video, it really is a simple process so i figured i could do that myself. . Here is my dedicated Porsche rocker grinder. . I have a machine shop so accuracy and machining the fixture was just regular straight forward work.

Making the fixture took about 3-4 hours as the rocker mount had to be absolutely square and perpendicular to the wheel. I checked the first hundred or so finished rockers on a cam tower with a good cam to insure full face contact. . I occasionally do them for a local Porsche shop for 3 years and haven't had any issues

Hard to see in the photo but the rocker on the left has heel and toe wear at the top of the face. . the right rocker is one of my reground and polished rockers. .

You also have to consider getting into the face hardening depth from the factory. . deep grooves and wear can sometimes be through that depth and then need re-hardening or they will wear . . somewhere around a cut of .005 or less seems to be acceptable. I have found that grinding to remove pitting is usually an excessive amount.

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Posted by: Mark Henry Sep 19 2015, 12:45 PM

Nice
My valve grinding machine has an attachment you could get for refacing rocker pads. I've been watching ebay for one to come up. If I had more call for this I would make one myself.