Concave pistons

[Gress]

Hey hey all. With the issues of pressure pockets building up along the outer edges of pistons, the furthest distance from the sparkplug, leading to pre-ignition in high poost engines, how come no manufacturers have made concave pistons with flat heads instead of doing wonky st with heads like is done in hemi's? Heads could remain simple and pistons could still be cast. Any ideas what I'm missing here?

[Boosted LS1]

You're missing that some manufacturers make concave pistons but still run a tight squish? A flat top with higher c/r can be managed by the engine management system depending on what they want to achieve I guess.

End gasses will always be an issue whatever the piston design.

[gazza285]

Concave pistons are heavier, and the ports end up with a bend in them.

[finlo]

Ford's Kent motor most famously.

[littleredrooster]

You're missing the fact that you did absolutely no research before posting this nonsense. It's been done many times, most notably with the Ford 'Kent' engines, as has already been pointed out. Old technology from 50+ years ago.

[Sevenhead]

Chamber-in-bowl and a flat head is called the Heron type. It was used on the Cosworth SCA, the Ford Crossflow and in the Jag V-12.

[njw1]

Sevenhead said:

Chamber-in-bowl and a flat head is called the Heron type. It was used on the Cosworth SCA, the Ford Crossflow and in the Jag V-12.

The Essex V6 was another one, although allegedly this was because it was originally meant to be a diesel engine.

[gazza285]

A more comprehensive list is to be found on Wikipedia.

Heron cylinder head.

[Boosted LS1]

^ Very good :-) I love PH.