Can you guys tell me what I did wrong

94GreenMachine

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In the process of fixing a blown head gasket, I looked at one of my rocker arms that was off centered on the valve and I noticed that the pedestal insert was cracked. I removed all the rocker arms and inspected all the pedestal inserts and they all had a hairline cracks in them. What could have caused this? I bolted them down to specs when I first put the cylinder heads on. Did I over tighten them? What do you guys think?
 

jimgt95

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Sounds like you overtightened them. Make sure you have the cam on it's base circle for each rocker when tightening them down to the proper spec. Replace the inserts.
 
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94GreenMachine

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I made sure it was on base circle, I rotated the engine until each intake and exhaust rocker went down once and were level. Now I did use a Autozone torque wrench to tighten them down 23ft. lbs. Anyway, how can you tell when they are tighen down enough not to back out or cause that annoying chatter but not too tight to repeat cracking the pedestal inserts?
 
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94GreenMachine

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I followed the specs that were in a Haynes book I purchased for my car and this link "http://www.allfordmustangs.com/Detailed/649.shtml" had the same torque specs. Now they could have been in that condition when I purchased the heads because the guy I got them from had them on a supercharged mustang and I really didn't inspect them that close before I put them on. The cracked one definitely wasn't like that but the hair line cracks could have very well been there.
 

jimgt95

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23 ft lbs is too much if you are using the Crane 1.7's in your signature. That spec may be for stock stamped rocker arms I don't know. I believe that you had to have the cam on it's base circle for each RR and tighten them down between 18-20 ft lbs within 1/4 turn of the bolt. Otherwise, you will need to add a shim under the rocker fulcrum to attain that result.

I just did this last fall. I rotated the engine 2-3 times to ensure that I was on the base circle and then tightened down one rocker. I did this for all 16 rockers. This is per the instructions that came with the Crane kit.
 
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94GreenMachine

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Here's a picture of a rocker and the pedestal insert. Each pedestal insert had a crack on the side you may be able to see what I am talking about. I bolted each rocker arm down individually like jimgt95 described but maybe I torqued them down too much, I definitely went higher 20 ft. lbs. Can I get some stronger replacements without buying a new set of rocker arms or going through Ford?

Rockers007.jpg

Rockers008.jpg
 

jimgt95

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94GreenMachine said:
Can I get some stronger replacements without buying a new set of rocker arms or going through Ford?

I doubt anybody will sell just the fulcrum seats by themselves. But I would call around to various manufacturers to see if they do. Ford would be the most expensive route if they could even get them for you. However, stronger replacements are not needed, you just need to torque them down properly and you will be good to go. What you need is the original directions for the Crane kit. That's what I followed and I didn't have a single problem.
 
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94GreenMachine

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I think I found the replacement part for my car at Summit Racing.

$15.99 part #CRN-36758PS-16
 

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