Quote:
Originally Posted by 700rpm
Dudley,
The bottom edge of the sleeves does seem sharp.
How does the ring depth affect the crosshatch?
The rod bearings are good; some of what you're seeing in the pix is just some shop handling debris, since cleaned off. There is no metal debris present, nor was there any in the oil, pan, or dipper tray when I dropped the pan.
I don't understand what you are referring to on the "cam" in regard to pistons.
The shop that did the sleeves and honing is Portland Engine Rebuilders, well respected and reputable. They confirmed yesterday that the cylinders were honed to 3.875 and the pistons fitted to .003. This may be the problem. They measured the pistons yesterday also, and they still read 3.8720.
The inside tops of the pistons are aluminum with no discoloring of any sort.
I have also ordered a new Brassworks radiator. As long as I'm spending money, I might as well spend it all!  |
1. Break the edges with some emery cloth,...no sharp edges..
2. Some rings are wider than others (for the depth of the grooves), IF the
ring does not rest below the land when you push it in the land,..it will put
excessive pressure on the cylinder walls,..make sense?
3. "cam in the piston",....Pistons are not round(more like an egg),..smaller
near the pin bosses. When I started out building race engines, the pistons
had very little cam and the clearance was in the .008"-.009" range,..to keep
them from sticking. They started putting MORE cam in the pistons and now
the clearance is in the .0025"- .0035" range. That will seal-up the holes
better and not "barrel face" the rings from the rocking motion on the pistons.
4. Heat and the radiator,..the inside of the pistons,...Best guess,..since there
is no color on the inside of the pistons(that's heat),..your problem could just
be that the pistons were set too tight in the holes,..I'd put more clearance
in the cylinders. BTW,..the "color, caramel" is oil that has stained the inside
of the piston,..when the piston is running at optimum temperature,..I look
for this when I freshen an engine..
Dudley