NazztyMonte Posted April 25, 2008 Share Posted April 25, 2008 Just got the motor primed and ready to start and realized two rocker stud holes are stripped and pretty much egg shaped. This is causing my roller rockers to sit off the the side of the valves. Called the local machine shop and he said he has seen factory heads up to 2/thousands off thats pretty much what mine are. He said dont go any further or I could blow the motor if they let go. What should I axpect for a price to fix this and should I just buy new after market aluminum heads instead of going through the trouble of fixing these ones ? It sucks because this motor was bought as zero miles and I have tons into it. Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 25, 2008 Share Posted April 25, 2008 as I told you in your PM, a heli-coil I thought was your best option, ask your machine shop if there are rocker studs that you can get with the end going into the head the next size up, then drill and tap them for the larger stud size. if that is not possible, then I would say new heads Link to comment Share on other sites More sharing options...
NazztyMonte Posted April 25, 2008 Author Share Posted April 25, 2008 Yeah, I will check on that. The guy working on it said the heads need to come off and I shouldnt bother fixing them. There is a lot of work done to them and they are LS6 heads so I cant see just throwing them out. Link to comment Share on other sites More sharing options...
McCall72 Posted April 25, 2008 Share Posted April 25, 2008 Had the same thing happen, and I ended up having to get a new head. Link to comment Share on other sites More sharing options...
NazztyMonte Posted April 25, 2008 Author Share Posted April 25, 2008 Did you find out before you got it running or after ? Link to comment Share on other sites More sharing options...
McCall72 Posted April 25, 2008 Share Posted April 25, 2008 After. I heard it very soon after firing it up though so I caught it before any damage was done. I found a place that sells heads either 1 at a time or by the pair (Clearwater Cylinder Heads) and bought a rebuilt one from them and haven't had a problem since.. www.cylinder-heads.com Link to comment Share on other sites More sharing options...
Mike 57 Posted April 28, 2008 Share Posted April 28, 2008 That is an easy fix for a good machine shop. Because of the angles involved with big blocks I would let a machine shop do it, and as Sam said have them helicoiled. Big blocks use 7/16 N/C thread in the rocker stud mounting holes. Most aftermarket aluminum heads have helicoils installed in the rocker stud holes because of the loads on the studs. Link to comment Share on other sites More sharing options...
Sam (Bones) Posted April 28, 2008 Share Posted April 28, 2008 and did you see the LS6 heads for sale in the for sale/wanted forum Link to comment Share on other sites More sharing options...
NazztyMonte Posted April 29, 2008 Author Share Posted April 29, 2008 Thanks guys. From what i hear it's more common in rectangle port heads then oval ports. If I go with new ones, I am buying oval ports with a new intake. Right now the car is fiinally running and it sounds nasty. The machine shop i spoke to said he has seen them right out of the factory like this. Link to comment Share on other sites More sharing options...
wallaby Posted April 29, 2008 Share Posted April 29, 2008 Well, I think that's where the term "Blueprinting" comes from. The factory slaps them together and tolerates some mis-alignment in the process. Blueprinting is when a machinist measures everything and makes corrections so the piece matches the specs called out on the original blueprint. Just because the head came from the factory that way, and your machinist has seen others like it, doesn't mean its a good thing. Is it something he can fix, or is he recommending you leave it alone? I would also imagine that a roller rocker would have a tougher time dealing with this problem than a stamped steel one. Link to comment Share on other sites More sharing options...
NazztyMonte Posted April 30, 2008 Author Share Posted April 30, 2008 I agree with you. I think your misunderstanding whats I said. I know it's not a good thing at all just becasue they have seen it. It is something that can be fixed but the head needs to come off. I was told today that the guide paltes can actually be cut and welded in order to get it right also. Im not sure what I will do either buy new aluminum heads or get this one fixed. My mechanic says it's not the guide plate. He swears it's the actual hole itself where the rocker stud goes in. Link to comment Share on other sites More sharing options...
Guest cstraub Posted May 8, 2008 Share Posted May 8, 2008 What you want is a timesert installed. These are much stronger then the Heli-coils. Not much more different installation technique but MUCH stronger system. Link to comment Share on other sites More sharing options...
NazztyMonte Posted May 8, 2008 Author Share Posted May 8, 2008 We actually fixed the problem pretty easy. We cut the guide plates, got the rocker in place dead center and welded the guide plates up. Worked like a charm. Link to comment Share on other sites More sharing options...
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