I have an Offenhauser cross ram with the single top w/ 700 DP Holley. I'm using old Cal Custom finned (no holes) valve covers. It's really hard to get the covers on. There's not enough clearance between the tip of the rocker arm and the manifold plenum to fit the valve cover flange in. My question is this: is there another rocker arm that has more clearance between the arm and the plenum? It's the pushrod end of the arm that interferes. I don't have room for the tall jamb nuts w/ set screws either, I'll need to use the stock type rocker arm nut. Oh also, it's only a problem on the passenger side. Driver's side slides right on. thx. .bjb
Well...first, you don't let us in on the exact rocker arm you are using...! Second, pretty much no matter what rocker arm you are using, you don't hack up the rocker to make a rocker cover fit..! In my opinion of course... I'd cut the outer flange of the rocker cover at the right (correct) angle to let it slide past the intake manifold. I had one of those manifolds years back, and the Chevy LT-1/Z-28 rocker covers fit nicely, so it shouldn't take too much wittling to get your Cal Custom covers to fit. Leave the rockers alone. Mike
You really need the Polly locks with roller rockers, those are the tall jamb nuts you referred to. You need a valve cover more like this | | instead of like this / \ . Or stock rocker arms. A spacer might help but I doubt it will solve all of the problems. Might even cause more problems with the fins and and the cross-ram.
First off pictures would help. But if I'm understanding your problem correctly, Mickey Thompson made a valve cover that was notched on the intake side for intake clearence. You could install the covers prior to installing the intake (as mentioned) but then you won't be able to service the valves without pulling the intake. In a racing situation, that would suck. Good luck!
Well obviously the first thing that comes to mind is that finned rocker covers are taller on the outside that non finned rocker covers. Next one must ask if you are running stud girdles, they take up a lot of room. I am running Crane rollers on heads with cantwed offset valves on my SBC and actually had the eitire setup insder a set of stock stamped steel covers. I used two gaskets and a 3/16 steel spacer but I do not have a stud girdle and that makes a real difference in how much room you have. I am running poly locks. I guess I what I am saying is that you have not give us enough information.
I have Crane rr's on mine and had to get tall valve covers. They look like this except the adjusting nut extends above the rocker arms a fair amount...and that's what would hit the old valve covers. I guess they changed them like below so guys didn't have to get tall style valve covers?
The cal customs are biggrt than most v/c's of the era and may cause problems(9 fin ones right?) now as stated before you could try to put the v/c's on 1st, but if you have solids it isnt exactly a permanent fix, personally i'd massage the rockers and mabey the v/c's to fit 1st. Thanks for putting this up tho i have a earlier offy crossram and never thought about clearing my harland sharp rockers that i was planning to put on my 301
I put mine in, in 1997 my nuts do extend a little above the rocker but I did actually have them under stamped steel covers for about a year when I was doing the sleeper thing. They were late covers (like in the later '70s late covers). My biggest problem is having canted valves the rockers want to run on the top edge of the rocker covers unless I run big boxy covers, I have gotten around that with smaller covers by egging the holes so I can slide the covers up hill a tad. But none of that answers the fellas question at all I suppose, I would really like to see his setup so we can come up with a solution for him.
How the hell does that Polly lock work? You should be able to get a open/ box end wrench on there with an Allen wrench at the same time.
I think this is the problem Jokester is talking about. I trimmed the flange as much as possible, but I still don't know how much trouble it's gonna be putting the valve cover on in "real life". This is just a mock up. I do realize that I'm gonna have to glue the vc gasket to the valve cover with gorilla snot to keep the gasket from moving around since I've ground the lip off the flange. Larry T
I had to trim the flange on my finned vette covers to clear the blower intake. I don't think the rockers were the problem just the intake.
That's kind of what I wondered! The hex of the nut stuck up above the rocker on mine. The only way I can figure you could get on those is to get one of those ratchet/socket sets that has an open end so you could stick the allen wrench through the hole in the end of the socket.
The tool above ^ still needs room to swing and won't with those rockers. It's possible with this tool: http://www.summitracing.com/parts/LSM-TQ-100-3/?rtype=10
They actually make a tool just for adjusting those or your next option is to get a box end wrench and bend it so that you can get it down in there then use a seperate allen wrench to tighten the poly lock up.
Or just grind some flats on a socket and wrench the socket and go through the socket hole with the Allen.
If they are like mine I think that it takes a 5/8 wrench so a spark plug socket with the flats already on it should work just fine.
Thanks for all the great responses (and a couple not so great). Larry T has the correct pics. I'm using all stock valve train, springs, retainers, nuts, arms, balls, everything. Someone suggested changing covers. NO! The only other cover I like is the no hole Offenhauser fins, and I have never found them in my budget range. Someone suggested putting the covers on and then the manifold. Are you nuts??????? I don't want to spend any more than 30 minutes adjusting the valves. The problem is with the pushrod end of the rocker arms only on cylinder #2. On my first try, I ground the flange considerably. I also ground quite a bit off the manifold in the same area. I finally ground a little (maybe .050) off the tip of the tip of the rocker. It went on barely, but it went on. I drove the car 6 miles. As I pulled in the drive I heard some rocker noise and felt like I had lost a cylinder. Compression check revealed all OK except zero on #2. Pulled the cover and found a two piece rocker arm laying next to the stud on the intake. The stud looked fine. I replaced it with another stock arm (no grinding this time), adjusted it and tried to put the cover back on. No fit. I hit it with my fist so I could trim away the shiny spot with a grinder. The occlusion is at the inner edge of the flange. I took off a little meat there this time. I'm a little leery of grinding so much that I make a hole in the cover. I ground some off the cover adjacent to both rockers on #2. I was able to pound the cover on, so it now runs. But I don't want to have to fight it every time I have the cover off. I can't remember what cam I put in because I've had the assembled motor on the stand for about 20 years. Really, 20 years. The valve covers are a recent addition. It may be that the cam will require long slot rockers, but I doubt it. I don't think it's that radical. Anyway, the critical distance is from the center of the pushrod to the rocker tip. I've seen some steel or stainless rockers with only a roller tip that use stock type adjusting nuts. Does any have a sample of these that they could measure? I think I'm only looking for maybe .060 or .070. Thanks for all your time and assistance. .bjb
you might try 1.6 rockers. The distance fromthe pivot to the pushrod socket is slightly less; however you would need to provide additional pushrod clearance in the cyl head and maybe different length pushrods. Personally, I'd get different valve covers.
You should be able to mic the cover and you can be sure of the thickness remaining. You should also be able to check the manifold thickness but it will be more difficult. Worst case is you need to get the manifold clearanced and welded. Another option would be to raise the intake slightly with an extra gasket. gaske Try stocker valve covers on for size just to see if they will work or stock rocker arms . In one post you say you have roller rockers and another you say everything is stock , balls, nuts, etc so its a bit confusing. Ultimately different covers is going to be the cheapest and easiest, if you want it and willing to payfor it , you can get your parts to work $$$$$ one modification leads to another.
Presently working on the identical setup with the Offenhauser cross-ram intake.The valve cover & rocker arm choices are critical to this setup! We have some short polished-aluminum covers on the shelf in stock that work well with this setup! They also clear the "poly-locks" on the rockers, very close, but clear! The manifold needed some machining near the valve cover rails for proper clearance. There doesn't appear to be any other recourse! The Comp Cam's "Pro-Magnum" rockers take care of the rocker issue, you will not be able to fit any "conventional" aluminum roller rockers with that intake setup (at least with the Offy intake, probably most other aftermarkets as well) due to the extreme clearance issues. I will say it does appear the factory "tin" covers would work, I have none here presently to try! This setup is so tight-fitting even the valve cover gaskets will need slight "trimming" inside the valve covers along the intake side to clear the pushrod side of the rockers. They will not pass the rockers during installation otherwise. Take this as a reliable "tip", while fitting all the components make absolutely certain the covers can be "R&R'd" with the intake bolted in place! Mentioned earlier here, DO NOT put the intake on last (after the covers), the covers MUST be removable for valve lashing and "checking". We have ours setup with outer springs only for dynoing, the inners will be installed after cam break-in.I will post some photos later at my "Webshots" location, will try to come back later with the link! (Add) See photos below! To the question below (Shaggy), I believe they are the Z-28/LT-1style covers, but they now fit. Thanks, Gary in N.Y. P.S. I have a set of the old style "finned" low G.M. covers here and they also do fit now, after some minor machining on the intake AND covers. These however will need add'l work along the intake side, probably some minor grinding? Double P.S. At one time I could place photos directly into the post, no more, not sure why??
So, youre going to spend money for new rocker arms, why not just buy the offenhauser valve covers you like.
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