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I am thinking of the wrist pin.
I believe that the oil pressure is to high to allow for a bad rod bearing, I have heard one before, does not sound like what I remembered.
Could the hole in a piston become excessive, wallowed out, so the pin would be banging around in the piston, has this happened?
Also, I need a refresher: to convert from a 360 to a 390 are the piston rods or pistons swapped out for shorter ones?
-John
Hey, folks
I got a bore cam to look at the #1 cylinder, was not that successful with the photos.
Looking through the spark plug hole with a flashlight, the cylinder looked well polished.
Here are three photos I took with the bore cam of the wall, they lack clear focus, and the camera was not easy to maneuver around in there, mostly wanted to look at the piston head.
It is hard to tell which section of the cylinder it was looking at, I am assuming it is about 1 o'clock.
The divit in the piston head which I assume is supposed to point toward the front of the engine did not appear to have any marks adjacent to it.
Because of the poor quality I was wondering if these grooves may be just light scratches because there seems to still be machining marks on the cylinder wall along with the grooves in a seemingly polished cylinder.
As always thanks for all your inputs!
-John
Not a good idea to use these pictures to diagnose, if they don't look like the reality you're describing. Because those make it look like one of the worst cylinder bores and piston tops I've ever seen on an engine that was still running!
It's hard to tell from here, if the patterning on the top of the piston is just reflection on carbon buildup, or if something small and hard was beating the living daylights out of the piston top.
Those grooves in the last picture are, I hope, fingernail depth with reflections making them look deep. But they do look DEEP with all caps, italicized and exclamation points!
Were the pics taken using the bore scope's software, or did you take screen-shots with your other camera?
Hey, Paul
I used a fairly inexpensive Klein borescope.
Unfortunately, the camera was supported by a rather stiff and thick long neck that did not perform very well in tight spaces especially through a spark hole.
I chose it because if could be positioned at an angle and would not flop.
I was rather surprised at the amount of carbon buildup myself, though the spark looked pretty clean.
I try to let my big engines warm up and keep them highway blown out as much as possible.
The carbon is soft and wet, the borescope actually scratched it off in places.
I think I need to adjust my carb, 'cause it looks like I am not only running rich, but I got a drip too.
The Klein, worked off of my phone which software allowed for stills and video.
-John
