OK, I was going to take my newly finished Cobra to work after lunch because some of my friends there wanted a look and you gotta give the fans what they want right? When I started the 468” FE it sounded sick on the pass side, as though it were missing consistently on one cylinder. I shut it down immediately (it ran for maybe 45 seconds and
oil pressure was about 85 psi) and pushed it inside to check things out. The first things to check were the spark plug wires, but for me to get my hands down there I have to pull the huge Holman Moody VCs off. When I got the vc off I saw that I was missing a rocker adjusting nut on the #4 intake and it was nowhere to be found on top of the head. So I started peering down into the lifter valley with a light to no avail. Then I removed the rocker assy. and push rods to get a better look. At this point I was still thinking “Oh, it’s not too bad. I’ll find this little bastage, fish it out with a magnet and I’ll be home free.” Right? Wrong-O o diseased yak breath! The thing was nowhere to be found in the lifter valley.
So I knew that I had to pull the pan and my mood was growing darker. Then, whilst standing there looking at the head trying to come up with a reason NOT to do this, I noticed that the valve stem on the offending valve wasn’t protruding from the retainer as much as the other valve stems were. In fact, it was damn near flush with the retainer and it looked like the retainer had come in contact with the rocker. Go over to the bench to look at the underside of the rocker and there’s a nice silver half circle showing where the retainer did indeed hit the rocker. WTF!? Now the head has to come off as well and I want to get it to the machine shop that assembled them before they close on Friday afternoon. So I thrashed to get the head off and to the shop where they to initially scratched their heads like I did. It looks like the keeper had somehow collapsed down inside the retainer and was slowly getting pulled down through it allowing the retainer to rise higher and higher on the valve until it came in contact with the rocker. I think this is when I first heard something wrong with the engine because this valve wasn’t operating properly. So they’ll be disassembling the head to check it out. Right now “WTF over?” is still going through my head.
But I digress; back to the rocker nut saga we go. So I get back from the machine shop and start my quest for the “F-ing” nut again. You know what? Pulling an
oil pan on a BB Cobra can be just as much of a hassle as pulling a head that’s retained by studs in the same car. When I installed the op I used “The Right Stuff” on the pan side of the gasket and nothing on the block side thinking that if I did have to pull it later that this would make it easier. Right? Wrong-O again o diseased weasel breath! I must’ve pushed every flat blade screw driver that I own (that would fit up in there at least) between the block and pan before I could get that f-ing thing popped loose. When it finally does come loose, again I see no nut and again I think “WTF!?” At that point I set about cleaning the pan while straining everything that came out through a stainless mesh to ensure that I don’t miss anything. While getting into the baffles and trap doors I see something that looks like a small piece of rubber belt or something of that nature. But when I rotate the pan it sounds metallic and when I fish it out I find that it’s a piece of the wayward nut. I wound up finding 2 more pieces that together I’m pretty sure constitute the whole thing. So this nut came off the rocker, fell into the lifter valley, through the reciprocating mass, got chopped up in the process and came to rest in 3 pieces in the pan. The crank and rods are a KC stroker kit and fill the block pretty well. In looking at the assy. I can find nothing that would show that nut’s passage from up top to the pan. The whole reciprocating assembly looks (for lack of a better way to say it) perfect. Really, it looks better now than when I buttoned it up with all that assembly lube and junk on it. Just for the heck of it I checked the #4 rod bearing and it’s perfect as well. Except for the fact that there is
oil all over everything in there you can’t tell that the engine has ever been run. Of course it only has about 200 miles on it to.
So now I’m waiting on the machine shop to tell me what they think happened with the valve. I’m tempted to rip apart the rest of the motor to see if I can find any damage that might have been done by the nut but I really don’t think that I’d find any.
The offending nut:
The rockers during assy.
