Originally Posted by frog
Originally Posted by Stu @ M Developments
Whilst the decompression plate will restore lost compression, it will by its very nature still increase the squish clearance by raising the cylinder head itself to a higher plane and as such is undesireable.
I understand that would be the case if the head was raised higher than the amount of removed material.
If say, 0.5 mm had been removed from the head, and the decompression plate was that same thickness, would it affect the squish area as you suggest ?
Yes.
The diagram above may help to show how a spacer plate will move the heads squish area upwards away from teh pistons, thus increasing the squish clearance.
Does that help?