November 2012 had exhaust valve wore into the seat. Discussed here: http://forums.yesterdaystractors.com/viewtopic.php?t=962450&highlight=
This past fall the problem came back. Both exhaust valves in that head are recessed into the seats. In 2012 valves and seats were replaced. Originally we thought we had a bad seat. Same machine shop replaced seats in 2012, two more bad seats? Or is something else going on here?
One mechanic told us that a worn cam could cause this if the valve wasn't opening enough it could build up heat in the valve. Checked cam lift with a dial indicator, 1E-.316, 2E-.316, 3E-.290, 4E-.320.
3 & 4 are the ones that are bad.
This engine was overhauled originally when it got lazy and we discovered a worn cam. We installed a new cam, bored the block for nozzles to oil cool the pistons like the 504's, installed oil cooler, stock Case manifold and turbo setup.
This past fall the problem came back. Both exhaust valves in that head are recessed into the seats. In 2012 valves and seats were replaced. Originally we thought we had a bad seat. Same machine shop replaced seats in 2012, two more bad seats? Or is something else going on here?
One mechanic told us that a worn cam could cause this if the valve wasn't opening enough it could build up heat in the valve. Checked cam lift with a dial indicator, 1E-.316, 2E-.316, 3E-.290, 4E-.320.
3 & 4 are the ones that are bad.
This engine was overhauled originally when it got lazy and we discovered a worn cam. We installed a new cam, bored the block for nozzles to oil cool the pistons like the 504's, installed oil cooler, stock Case manifold and turbo setup.
