Breathing new life into the 318 in the Scamp!
#5 got loose.
Looks like the cap came off about 1/16". The nuts were still on.
I'm glad that I shut it down immediately and that it wasn't run on it.
Now, this is a first for me, but completely understandable, considering I heard it start while it was idling parked in front of the garage and shut it off, then pushed it into the garage where it sat and the engine pulled...
The journal has no visible or measurable damage. The finish looks fine. I looked at the bearings, they are still seated in the rod and cap. They have slightly brighter spots on them, where the journal was coming off of the bearing and going back on.
I checked the journal at the high points of where I thought it would have slapped, with a caliper at each end of the journal and the middle, through 90° of the rotation and I'm seeing less than .0005" in difference.
I'm going to plastigage all of the journals and plastigage the #5 journal in three places on the tdc side of the journal, 45° from each other in the opposite direction of crank rotation to check for possible damage wear from the rod side bearing slapping down. I've looked at it with a flashlight and I can't see any visible differences in the journal. I think the knock sound I was hearing was actually the piston slapping the cylinder head.
I think the soft metal of the bearings took any light blow that it may have been put through. The bearing almost looks like it could even be reused, but I'm not going to risk that.
I'm going to replace all of the bearings with some Clevite 77s and plastigage all of the rod bearings. If everything checks out ok, the pan is going back on and it's going in. I want to tune this thing!
Not being satisfied with only finding what was wrong, I checked my friends micro-torque wrench that was used to do everything. I went and bought a Craftsman beam torque wrench and all of the rest of the rod cap nuts were at 32 ft lbs. I checked the wrench with a double ended 3/8 socket and it clicks at 13-14lbs shy of actual torque at 45lbs showing on the wrench.
I'll never trust a micro-torque on another engine or transmission build, ever again. I'm also going to retorque everything else on the engine.
This will give me the opportunity to put some o2 sensor nuts on the exhaust, so I can check AFR and get the carb dialed in. I think the secondaries are lean. I wanna get this thing tuned.
Page 6 and this thread has 6,666 views. At least I don't need to buy the head gaskets for the 3rd time. I want this "carb swap" over with.