We headed up to Des Moines, IA Friday for the Heartland Good Guys show. Stopped mid-way to top off tanks & stretch legs, then did the last 100 miles. All was fine at the stop, but as we pulled off of I35 I heard a distinct tap-tap-tap from my engine. We went ahead and checked in to the hotel, and agreed to make a run to a local car wash to get rid of the bugs & road grime. While there we used a big, long screw driver as a stethoscope and isolated it to the passenger side, near the front, but there was no miss. On the way to the fair grounds across town the tap increased a bit, then it seemed to develop a miss. We got registered, and idled in to find a place to park. About three hours later one of my buddies asked if we were going to pull that valve cover before we went back to the hotel, since it was cool by now, almost 4pm. When we removed the cover this is what we found:
Attachment 58323
From the review of symptoms I think that the intake on #1 lost the pin retaining the roller, and that rocker started slapping the valve and dropped the pushrod out of the cup. At that point the rocker went crooked and bent that pushrod into the "S". As we were going from the car wash to the fairgrounds I'm guessing that the pin and/or roller got tangled in the #1 exhaust, and that casting snapped causing the total miss.
We scrambled, and were able to hook up with a couple of guys from Karl Performance & Karl Kustom in Ankany, a suburb of Des Moines. He made a call and told us that he had a set of replacement Scorpion rockers at the shop, and that he thought they could scrounge up at least two pushrods of the proper length, or very close to the same, and that they were open until 6pm. As he was giving us directions Jim Hidy had his car keys in his hand, and he asked if we had a way to get there - he was ready to give us his car for the trip!! We had transportation, so we ran out, got the rockers and once back had the two replaced in ten to fifteen minutes. A quick re-start and it sounded good.
This morning we headed back, and it made the run without a hitch, running about 80mph most of the time. It's cooling in the barn now, and I'll be changing out the remainder of the set, along with new push rods for grins. While I'm messing with it I'm going to compression check #1 to ensure that everything is OK there, and may borrow a scope to peek inside that one, too. I'd really prefer to NOT pull the head, and based on the way it acted I don't see any reason to pull it right now, providing the compression is good.
