Crane 1.6 rockers gone bad!

[geoffinbc]

Just to add a point to this rocker situation. Specs say that you need the oil hole in the rocker and pushrod to be aligned through at LEAST 30% of the cycle in order to provide adequate oil to the rockers.

[AaronGTR]

Hey guys, been a while since I could work on this problem (life got in the way) but I have a few updates. I had a chance to check a few things tonight.

First about the clearance with stock rockers and comp titanium LS spring retainers. It's seems it's not a problem. The comp retainers are only .002 taller than stock, but sit a little higher on the valve stem so they have .01 less clearance. They still clear though (I could see light between them), and they are closest when the valve is closed. As the valve opens the rocker tip moves away from the crown of the retainer so they won't touch. One thing I noted was the stock retainer has a bit of slop inside the end of the LS6 valve spring while the comp retainer fit snug, so they should control spring motion better.

Now the bad news. I got the two steel comp rockers I order from summit to test fit. One was supposed to be a "narrow body" for ford v8 and the other was a SBC standard body. They were the exact same rocker. They had exactly the same measurements, so neither of them fit. They were 1.611" wide and they hit at the fulcrum. The stockers are 1.323" and the cranes were 1.2" by comparison. So as far as I can find, no one makes any kind of rocker that will fit our engines except for narrow body SBC aluminum. No option for steel or chromoly, so we have no choice but the mod the rocker nose for clearance.

Haven't decided yet if I'm going to just put the stockers back on and get new pushrods, or get some different aluminum rockers. Either way I'll have to get new pushrods. If I get new Al rockers though I already have everything else I need so I'd just need the rockers and pushrods. I won't be grinding much off the LIM runners this time though. Maybe just the casting surface and not much more. It didn't gain me much clearance last time and I ruined a LIM doing it. There's much more clearance to gain by rounding the nose of the rocker, so I'll try to get most of it there instead. I might grind the nose on all of them and weight balance them on my digital scale, but I'm not sure if there's really any need for that. If I do go this route, I'll be rinsing out the fulcrum bearings thoroughly before I install them this time.

Last thing, I tried the trick with the ink on the valve stem tip and it worked pretty well. I re-installed two of the crane rockers with the pushrods I had been using and set them at the same preset as before. Turned the engine by hand a few times and they left a good mark in the ink. They were stopping about half way up from centerline when the valve closed which wasn't too bad. I'd already bleed the lifters, so when opening the valves they didn't open all the way and I couldn't see exactly where they would stop. I can say that it didn't look like they'd go quite as far down, and if they had been adjusted for the proper pre-load they would have shifted even further up. So they were a bit shorter than they should have been, but I can't say how much. I have a checker pushrod now, so I'll be ordering the right length next time.

Oh yeah, and I also sent my TOG headers out to jet-hot to get stripped and recoated with their sterling extreme ceramic. The stock coating was starting to come off and they were rusting. There was some uneven weld splatter around the inside of a few of the primaries where they are welded into the flange, so I cleaned those up a little with a grinder too before I sent them out. They should be here tomorrow.