Insulated diesel engine combustion chamber

Claim 1

A heat insulated combustion chamber for a diesel engine having a cylinder block member with a bore therein slidably receiving a piston member closing one end of the bore, a cylinder head member overlying the block member to cover the same and having a recess aligned with and cooperating with the bore and piston member to define a combustion chamber, and heat insulating spacer type extenders of ceramic material of substantial thickness and of low thermal conductivity secured to each of the piston member and cylinder block member and cylinder head member and extending axially from and interacting with the same to increase axial distances between normally adjacent surfaces for reducing outflow of heat from the combustion chamber into the piston member and block member and cylinder head member, a single bolt connecting the piston extender to the piston member, the extender of the cylinder block member and piston member having equal axial extents, the extender of the cylinder head member extending in a plane normal to the cylinder bore and above that of the extenders of the piston member and cylinder block member, and air gaps within each of the extenders extending over a substantial portion of the thickness thereof between the outer surfaces of the extenders and its respective member to which it is attached to reduce the available heat flow paths from the combustion chamber.