Heron cylinder head
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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.
While it is possible for a flat cylinder head to be combined with simple flat-top pistons, that option 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. ("Squish" is an effect in internal combustion engines whereby turbulence is created when the compressed charge is "squished" as the piston reaches TDC. Such turbulence is desirable as it promotes more extensive mixing of the fuel/air mixture).
Pros & ConsAdvantages include: simplicity of manufacture; compact dimensions; accuracy of the flat machined surface; simplified valve-gear; efficient combustion with good fuel economy.Disadvantages include: the greater size and weight of each piston; volumetric efficiency poorer than conventional cylinder heads.
Applications |
| Lamborghini Urraco P250 |
Franco Lambertini
| Moto Morini 3・1/2 & 500 |
| Moto Guzzi middle V2 |
| Puma racing engines |
| Ford Kent engine |
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The first kent engines were non crossflow- and used in anglias and MK1 cortinas (1000cc, 1200cc and 1500cc). these had afully chambered head.and conventional pistons when ford updated the kent engine they made it crossflow and heron head in about 1967 -just in time for the mk2 cortina and later 60's the escort and capri(anglia was dead by this time)
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KENT UNIT Mk.I head
KENT UNIT Mk.II head
| Jaguar V12 engine |
| Volvo 900 / 700 |
