Quote Originally Posted by Shed tuner View Post
reckon you could JB weld it all up in there, smooth it off and redrill the port ? Or just melt a load of solder down it ?
would be so much easier if you could get the bugger off !


It worse than I thought, Jon.

Having another poke around in the cylinder revealed that it isn't just a radial groove round the outside of the plug --- it's has a radius round the end of the plug the same as the radius on the front of the piston.

Then there's a radial groove behind that section.


By a quick calculation :-

The transfer port has a volume of 0.078cc

The plug radius has a volume of 0.176cc

So the total lost volume is 0.078 + 0.176 = 0.254cc


The swept volume of the cylinder is 43.12cc

So the static compression ratio is 43.12 /0.254 = 170:1

That figure doesn't include the full radial groove behind the radius or the hemispherical cutout in the front of the plug, so I reckon the static compression ratio is nearer to 100:1 --- no wonder it was getting slammy.


It's an absolute knacker, but I'll give it some thought.



All the best Mick