HI, I have a 52 G9 that has a habit of seizing the left cylinder after running for a while. The perceived wisdom appears to be to drill a 3/16 hole in to the inlet cam tunnel to let oil drip down to the crank and to be splahed around the cylibder walls preventing? the sizures. Has any body done this on their bike and where should I drill the hole?
All help gratefully received,
G9 Cam tunnel drilling
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billmantle
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wilko
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G9 Cam tunnel drilling
There are lots of oiling mods that AMC tried but remember they originally used wire wound pistons with .001" clearance where it would be more critical. I suggest honing the left cylinder out by a few more thou on that side but re-measure the right side while you're at it!
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GSAX1
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G9 Cam tunnel drilling
I agree with wilko: check the piston-to-cylinder clearance first. Do not bodge the crankcase. The oil reservoar in the cam tunnels is there for ensuring lubrication to the cams and followers upon startup.
The oil normally goes via the cam tunnels to the cam drive side, and from there it goes to the crankcase and sump. Any "shortcut" from the cam tunnels will not send any more oil to the crankcase, but it will likely increase wear on the cam followers.
Michael
The oil normally goes via the cam tunnels to the cam drive side, and from there it goes to the crankcase and sump. Any "shortcut" from the cam tunnels will not send any more oil to the crankcase, but it will likely increase wear on the cam followers.
Michael
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paul knapp
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G9 Cam tunnel drilling
I am curious how you know it's the left cylinder that is seizing!
If it were lack of lubrication, and since it's happened a few times, I would imagine the piston/rings/bore would be damaged by now.
I agree per above, not enough clearance on the piston.
Paul
If it were lack of lubrication, and since it's happened a few times, I would imagine the piston/rings/bore would be damaged by now.
I agree per above, not enough clearance on the piston.
Paul
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J.B.Nicholson
Don't worry about the world coming to an end today. It's already tomorrow in Australia!
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billmantle
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G9 Cam tunnel drilling
quote:
I am curious how you know it's the left cylinder that is seizing!
If it were lack of lubrication, and since it's happened a few times, I would imagine the piston/rings/bore would be damaged by now.
I agree per above, not enough clearance on the piston.
Paul
I know it's the left side cos I've taken it apart!
Joking aside, All comments gratefully received and in principle I agree and have already had a rebore to wider tolerances. but the advice in the club's fact sheet "Twin Engines, Potential Problems" on twins recommends drilling a hole in the inlet cam tunnel to allow oil to dribble down on the crankshaft.
I am curious how you know it's the left cylinder that is seizing!
If it were lack of lubrication, and since it's happened a few times, I would imagine the piston/rings/bore would be damaged by now.
I agree per above, not enough clearance on the piston.
Paul
I know it's the left side cos I've taken it apart!
Joking aside, All comments gratefully received and in principle I agree and have already had a rebore to wider tolerances. but the advice in the club's fact sheet "Twin Engines, Potential Problems" on twins recommends drilling a hole in the inlet cam tunnel to allow oil to dribble down on the crankshaft.