Wet Piston Crowns?

Hey All,

Rebuilt the top end last year and put about 800 miles on this year before I began hearing what sounded like valve noises on cyl #3-#4. Took the valve cover off to check valve clearances and discovered all clearances were less than the minimum .05 mm. They were .10-.15mm 800 miles ago and are now touching or almost touching the shims! Can't figure that one out.

Anyways I took the head off to investigate and found cyl #1 and #2 are wet with oil! What gives?! Engine has new rings, honed cylinders, lapped valves, new valve seals and compression is now 150-155 psi all around. Please offer advice, thanks!

Assuming the rebuild included lapping the valves or touching up the seats with a cutter, then yor valve clearance situation is perfectly normal. Even after the top end is fully broken in, valve clearances will get smaller as the miles pile up because the valves get pounded deeper into their seats.
So far as I know, there are only two ways oil can get on top of the pistons, well, three if you count pouring it in on purpose. It either has to come past the rings or past the valve seals. Maybe the rings are not yet fully seated, maybe the oil rings on those two pistons got overlapped during install, or maybe two of the valve stem seals got nicked on a sharp edge during installation.

Or maybe they are getting flooded with gas due to no clearances. Why take the head off?
Steve

New valve seals can easy destroyed with the wrong installation method.
In every set of new valve seal should be a set of two plastic tubes.
These tubes protecting the sealing lip that can be cut off by the sharp valve keeper grooves!!!

Thanks guys! I'm betting it's the valve seals. Gonna remove all valves and install another new set using the plastic tubs. Didn't notice them before, but they must come with new valve seal kit? Pic attached showing wet Cyl # and #2.

If no plastic tubes are in the valve stem seal kit made your own from a drinking straw.
Forming the top of the tube with some heat gun.

KZ1000P1995 wrote: Thanks guys! I'm betting it's the valve seals. Gonna remove all valves and install another new set using the plastic tubs. Didn't notice them before, but they must come with new valve seal kit? Pic attached showing wet Cyl # and #2.

WOW, in looking at this pic, those pistons are soaking wet! Was blue smoke coming out of the exhaust, or is that gas?

Bad valve seals will normally smoke upon startup, then clear up as the oil gets burnt off. (oil runs down the guide when the engine is off) With rings, it will smoke all of the time. Pick your poison.

As texaskz pointed out, it is extremely easy to overlap the oil expander ring, having done it myself. these motors are really tricky in some aspects as of assembly (rings and cam timing) and that expander ring pretty much overlaps it's self when putting the block on. I had to give up my makeshift ring compressor and carefully work the rings into the bores with my fingernails while double and triple checking their progress with a flashlight. The taper takes over once everything is properly started, and centered in the bore.

I managed to overlap the oil expander on one hole using this method.


hope this helps.

Maybe you get foolen by the picture, but the cylinder wall is not looking good on the photo???

gordone wrote: Maybe you get foolen by the picture, but the cylinder wall is not looking good on the photo???

You are correct Gordone. I did not even notice that #2 hole., just the dripping wet piston domes. WTF is up with that cylinder wall? IS that #2 bore wasted, or is that just oil dripping off of the cylinder walls?

Top of that piston looks weird, too. Hopefully what we are seeing is some strange reflection.

Like to see better pic of #2.
Steve

Hey Fellas,

Okay, so I looked closely at #2 cylinder with a flashlight and it looks GREAT. I had it honed by a shop and installed new rings 800 miles ago. Still beautiful cross-hatch with no other markings. VERY dark and wet combustion ring at the top of Cyl #2 though. Hard to imagine that Cyl #1 and especially #2 ever fired! I definitely checked exhaust pipes on warm up regularly and they all heated somewhat uniformly.

If memory serves, it would smoke on startup but then run smoke-less after warmed up. So, two possible mistakes: I have repeatedly installed and removed the valves without a plastic condom (haha) AND I could have easily overlapped the oil expander rings, as I installed the cylinders by hand and remember being concerned about the rings. Hesitant to remove the cylinders, as I already have a new head gasket but can't find a new cylinder gasket without buying the whole top-end gasket kit.

Questions: Are the valve seals definitely ruined by installing the valves multiple times without a condom? Should I remove the cylinders to check the oil control rings? Thanks guys!