Heron cylinder head

A Heron cylinder head, or simply Heron head, is a design for the combustion chambers of the cylinder head on an internal combustion piston engine. The head is machined flat, with recesses only for inlet and exhaust valves, spark plugs, injectors and so on. The combustion chamber itself is contained within a dished depression in the top of the piston. The Heron head is suitable for petrol and diesel engines, for ohv and ohc valve-gear, and for small and large engine displacement capacities.

Contents

• Pros Cons
• Applications
• References

A flat cylinder head can be combined with simple flat-top pistons, but that choice ignores the reasons for having a depression in the top of each piston, namely: (i) it provides a compact space for combustion to begin, allowing an optimal flame front; and (ii) it creates significant squish as the piston reaches TDC. This causes turbulence, which is desirable because it promotes more extensive mixing of the fuel/air mixture: cf: cf1, cf2, cf3).