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Listeroid Engines / Knocking, now what?
« on: February 12, 2024, 10:45:02 PM »
So, at the conclusion of the previous thread (Spun the rod bearing) I replied to keith71 with my repair update.
Without going into detail again, after about 8 hours of run-in over a few days, a loud knock suddenly appeared.
My first thought was "check the keys" They seemed OK, I spent a lot of time fitting new ones and they fit pretty well.
Pulled keys out and did a fitting check with a sharpie, nice contact along the tops of both keys.
One flywheel has a wider keyway, about .012" wider than the Gib, although the Gib fits nicely into the crank keyway. I shimmed the side of the wheel keyway on installation of the key, good fit, as far as I can tell.
I then pulled the bottom end to check the rod bearing again. Clearance was less than .003", re torqued. Everything rotated smoothly and felt good.
Restart ..........no joy. Same loud knocking sound. If fuel is cut, the knock disappears. I would think that the problem is an improperly fitted key, but maybe not, as I have fitted them as well as I am able, and I'm sure the fitting is better than I did 12 years ago.
Maybe timing? I don't know if this would cause the problem. The flywheel timing mark shows the correct position relative to the "creak" I did not change anything there from before the original sand damage.
Any ideas? I am out.
Assume I know nothing........that's how I am feeling this afternoon!
Cheers
Hugh
Without going into detail again, after about 8 hours of run-in over a few days, a loud knock suddenly appeared.
My first thought was "check the keys" They seemed OK, I spent a lot of time fitting new ones and they fit pretty well.
Pulled keys out and did a fitting check with a sharpie, nice contact along the tops of both keys.
One flywheel has a wider keyway, about .012" wider than the Gib, although the Gib fits nicely into the crank keyway. I shimmed the side of the wheel keyway on installation of the key, good fit, as far as I can tell.
I then pulled the bottom end to check the rod bearing again. Clearance was less than .003", re torqued. Everything rotated smoothly and felt good.
Restart ..........no joy. Same loud knocking sound. If fuel is cut, the knock disappears. I would think that the problem is an improperly fitted key, but maybe not, as I have fitted them as well as I am able, and I'm sure the fitting is better than I did 12 years ago.
Maybe timing? I don't know if this would cause the problem. The flywheel timing mark shows the correct position relative to the "creak" I did not change anything there from before the original sand damage.
Any ideas? I am out.
Assume I know nothing........that's how I am feeling this afternoon!
Cheers
Hugh