Ok, this is whats going on. I just rebuilt my engine to a 383 stroker. Before I started there was some rocker hitting valve cover noise. The heads I am using are corvette aluminum center bolt 12556463. I got new pushrods and the heads already have guide plates. I got the engine back to gether and am getting valve cover noise still. When I take the valve covers off it sounds fine. I bought tall aluminum aftermarket valve covers to see if this would stop the noise. But its louder. It sounds like its coming from the #8. I bought a set of roller rockers from summit. but they rub the middles and make valve noise also. They are 1.6 but i think that i might need 1.5's. Can anyone help. I was looking at new heads and on the instructions it said that you might have to relieve the back of the intake rocker to get it to clear? If anyone can help please. Cause im about to buy new heads and get rid of these centerbolt ones.Should i take the guide plates out?

 

Do you see any damage on the inside of the valve cover to indicate where its hitting? With tall valve covers you really shouldnt have any clearance issues. One thing that comes to mind is make sure that the lip of the valve cover is not resting on the intake manifold. Ive had that happen and it dosnt allow the valve cover to sit strait causeing the rockers to hit the valve cover.

 

I have had some scrapping on the bolt boss for the centerbolts. Do i need to do some grinding on the valve cover to make it clear?

 

Thats a bit of a supprise with a tall valve cover i wouldnt thing it would be an issue. Then again with larger 1.6 roller rockers and a big cam i guess anything possable. I personally dont like to grind away on something like that your could i suppose ide recomend getting a valve cover spacer or try thr old double gasket trick. Befor grinding or buying parts you dont know if thell help just take 2 cork gaskets basically glue them together with gasket maker and then install install it. If that dosnt cause it to clear the valve covers then youve got some other issues to look into.

 

Get the ones made out of thicker cork as well.

 

I think i figured it out. The center boss is to thick and making the roller turn slightly to the side making the back corner of the roller rocker to hit the valve cover. I think if i take a dremmel to the sides of the center bosses i can straighten them out and make them not hit the covers.

 

Instead of grinding away, did you get the narrow body roller rockers? These are made for center bolt valve covers. I have these in mine with the stock height valve covers and do not have any issue with them.

 

You mentioned roller rockers, are they self aligning or non-aligning? If non-aligning, which is what they sound like (you mentioned already having guide plates).

Need to use aftermarket hardened guide plates. The stock ones are soft and the slot is wider then a true guide plate.

If the rockers you bough are a wide-body style they may be hitting the bracing or valve cover mounting bolts. Look for marks on the rockers to try to see where they are hitting.

RBob.