What Are You Doing To/With Your Car Today?
This afternoon I started to recheck my valve clearances. But the universe had other plans...
A couple of days ago, as the engine stopped I heard an interesting metallic "clinking" for a second (sounded like something hitting the valley pan, or possibly the #2 header tube that runs very near the shock tower). It wasn't there at idle (or higher), and I couldn't find anything and it didn't come back. So I drove it to two cruise-ins (about 10 miles each, one-way) on Fri and Sat, no problems or noises, ran it up to 5200 a couple of times.
Today I fired it to warm up for lash setting and cold vs. hot check, and once again at almost-stalling engine rpm the clanking came back, louder than before! So I shut it down and decided to disassemble as necessary until I found it. I clearanced the header tube, and pulled the valve covers. No loose pushrods or broken rocker arms... ok. I started running the valves in firing order from #1, and when I got to #4 I could see that one keeper half on the exhaust valve wasn't properly seated and had popped up a little
Oh poop (paraphrasing), I said, that clanking may have been the valve meeting the piston 
A close look at the rest of the valvetrain showed the same problem on #5 intake. Naturally, one on each head, so if those valves are bent, both heads have to come off - in other words, the entire head R&R has to be done over again.
Before you ask, yes, I did check piston-to-valve clearance and the intake measured .114" and exhaust much larger. So I'm somewhat at a loss as to why these keepers came loose - I was careful to check all 16 when assembling the seals and springs on the bench, to make sure they were seated.
I guess it's time to order another set of 10 degree locks at a minimum. Maybe I'll get lucky and those two valves and guides will be intact and I won't have to pull the heads for repair, but I'm not holding my breath. Right now I am walking away for the night and taking a few deep breaths.
This afternoon I started to recheck my valve clearances. But the universe had other plans...
A couple of days ago, as the engine stopped I heard an interesting metallic "clinking" for a second (sounded like something hitting the valley pan, or possibly the #2 header tube that runs very near the shock tower). It wasn't there at idle (or higher), and I couldn't find anything and it didn't come back. So I drove it to two cruise-ins (about 10 miles each, one-way) on Fri and Sat, no problems or noises, ran it up to 5200 a couple of times.
Today I fired it to warm up for lash setting and cold vs. hot check, and once again at almost-stalling engine rpm the clanking came back, louder than before! So I shut it down and decided to disassemble as necessary until I found it. I clearanced the header tube, and pulled the valve covers. No loose pushrods or broken rocker arms... ok. I started running the valves in firing order from #1, and when I got to #4 I could see that one keeper half on the exhaust valve wasn't properly seated and had popped up a little
A close look at the rest of the valvetrain showed the same problem on #5 intake. Naturally, one on each head, so if those valves are bent, both heads have to come off - in other words, the entire head R&R has to be done over again.
Before you ask, yes, I did check piston-to-valve clearance and the intake measured .114" and exhaust much larger. So I'm somewhat at a loss as to why these keepers came loose - I was careful to check all 16 when assembling the seals and springs on the bench, to make sure they were seated.
I guess it's time to order another set of 10 degree locks at a minimum. Maybe I'll get lucky and those two valves and guides will be intact and I won't have to pull the heads for repair, but I'm not holding my breath. Right now I am walking away for the night and taking a few deep breaths.