Yanmar 1gm10 bent con rod

[kieron riley]

I’ve been reading all sorts of web pages on the subject , and some mention that a bent crank shaft ( or its cause ) can also cause damage to the cam shaft , can anyone explain how this could happen . Thanks .Kieron

 

[Tranona]

That is confusing. Your title is bent con rod which is not unknown on a 1GM and usually caused by a hydraulic lock in the cylinder, but you then ak about a bent crankshaft affecting the camshaft. Bent crankshafts are unusual and not sure what would cause that nor how it might affect the camshaft.

 

[kieron riley]

Sorry should read bent con rod. Not crank shaft

 

[Sailing steve]

A hydraulic lock may well bend the con rod but I can't see any mechanism there causing any damage to the valve train.

The bottom end of the 1GM10 is as tough as old boots but there is a small possibility that a foreign object such as a bolt or nut (mine were finger tight on the air filter housing) being drawn into the engine, jamming the inlet valve open which will subsequently collide with the piston on the next upward stroke causing catastrophic damage to the piston and valve and possibly bending a pushrod or snapping a rocker arm too but even then I'd doubt even that event would damage the camshaft.

 

[DownWest]

A hydraulic lock may well bend the con rod but I can't see any mechanism there causing any damage to the valve train.

The bottom end of the 1GM10 is as tough as old boots but there is a small possibility that a foreign object such as a bolt or nut (mine were finger tight on the air filter housing) being drawn into the engine, jamming the inlet valve open which will subsequently collide with the piston on the next upward stroke causing catastrophic damage to the piston and valve and possibly bending a pushrod or snapping a rocker arm too but even then I'd doubt even that event would damage the camshaft.

Had a bent rod on a Vetus twin from hydraulic lock. Just swopped out the rod (Mitsubishi) and all was fine. But, jamming the valve gear might cause damage to the cam?

 

[Sailing steve]

Had a bent rod on a Vetus twin from hydraulic lock. Just swopped out the rod (Mitsubishi) and all was fine. But, jamming the valve gear might cause damage to the cam?

Depending on how and what jammed the valve gear, but you're more likely to bend a valve or pushrod or damage the head or piston rather than cause any drama to the camshaft.

Or if you're a really lucky boy and running at idle or low load the engine might just come to a an abrupt stop.

 

[DownWest]

Depending on how and what jammed the valve gear, but you're more likely to bend a valve or pushrod or damage the head or piston rather than cause any drama to the camshaft.

Or if you're a really lucky boy and running at idle or low load the engine might just come to a an abrupt stop.

Just thinking that if some bit of junk got in between the valve and the piston, if the rocker didn't break, then the load on the cam could damage the hard surface of the cam lobe

 

[Sailing steve]

Well it could. I'd imagine any junk in the chamber would more likely bend the valve or break through the piston crown though.

Carburised surfaces such as those on the cam lobe usually fail through wear because of lubrication failure rather than impact damage.