Valve-train valve-cover clearance

[acaskie]

Has anyone had problems with valve-train clearance(width, not height) using Cobra open-letter valve-covers? Are some castings thicker than others?

[CobraEd]

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[Tony Ripepi]

Hello to All,

When I put the Aluminum open letter valve covers over the Comp Cam roller rockers on my 427 they interferred with the stands on the ends. Had to machine out about a 1/4 inch of material for clearance....

Come to find out later this is pretty common depending on which valve covers you use.

Best Regards,

Tony Ripepi

[Jeff Frigo]

Tony is right. If you are running the Comp. Cams roller rockers and shafts, or the heavy duty Dove set-up, the inside ends of the R/A covers need a little clearencing with a die grinder to clear the end stands. Mine only needed about .060 on each side. I am running a cam with .625 lift (anybody got anything bigger on pump gas?) with no interferance at all between the rocker arms and the tops of the R/A covers. Even the chromed sheet metal ones are tight, but with a little help from your fist, they also fit.


Jeff

[Cobranut]

Jeff,

I'm running a little over .650" lift with Harland Sharp rockers and custom built end stands.
I think I remember having to clearance the oil breather baffles a bit. No problems with the end stands.

Later,

[Jeff Frigo]

Dave:

Is your motor on pump gas, or something else. What type of duration at .050 lift? Whos heads? HP? Compresion? Just curious. I will share all of this with you if you want, give me a private e-mail. The reason you didn't have problems on the ends is because you only have 4 stands, not 6. You only get 6 with the Copm. Cams or heavy duty (not regular) Dove set-up.



Jeff

[chopper]

I have a set of the finned covers which the previous owner swore up and down were original mid-60s vintage. (I can't verify that but they were certainly dirty enough when I bought them to have been original.) Anyway, I had the same problem with clearance on the Dove end stanchions. A little light work with the Dremel tool provided the necessary clearance. I also found, with the original chromed pent-roof covers, that the fit over the end stanchions was an interference fit.

Incidently, the flat bottoms on the aluminum covers don't match up well with the mating surface of the Edelbrock aluminum heads and they have a tendency to dribble small amounts of oil. Even with the gaskets glued to the valve covers, they don't seal very well. Gosh, an FE engine that leaks oil.... What's this world coming to?

[Silk]

Any of you use roller-tip rockers with the finned open letter valve covers? Any unusual clearance problems? I tried the roller-tips with the valve cover spacers, and it was no go. Not even close. Looks like it might fit without the spacers, but I haven't given it a try yet.

[acaskie]

Hey Silk, Why are you worrying about valve train clearance when you could be obsessing about fuel lines?--Boy

[Silk]

Boy - It's simple. The valve train problem will undoubtedly prove much more complex and costly to resolve before I'm through. Why obsess about the simple and inexpensive when a much grander issue lurks?

By the way, the valve train noise persists. That's why I'm wondering about the roller tips as a possible solution. If they won't work with the spacers - which I now know, I'd like to know if they'll fit with the open face cobra valve covers sans spacers before I go through another zillion dollars in gaskets trying to find out.

[Dan Heck]

Silk:

I am using a set of open-letter cobra valve covers with the Comp Cams 'Magnum' roller tip rockers on my 351W and everything clears OK. These covers do not have the baffle inside and are original-era "Buddy Bar" castings.

Dan

[juanclean]

i am looking for Cobra valve covers for my 302