Piston Dome

Fungsi dari piston high dome atau jenong adalah meningkatkan kualitas kompresi saat piston mentok di Titik Mati Atas. Walaupun ketika piston biasa diganti dengan piston jenong, sebenarnya langkah piston tidak berubah, namun karena saat TMA penampang piston lebih mepet ke kepala silinder bila memakai piston jenong, kompresi yang dihasilkan relatif lebih tinggi dari pada menggunakan piston biasa.

Higher compression will produce more power and torque are good also, but must be accommodated with octane fuel is higher than when using a regular piston (because compression has been relatively higher). Also becomes hotter because the engine (compression has increased) cooling the engine should be good anyway. Usually some modifier that already apply piston dome, adding that the oil cooler heat release could be better than before. However, when the dome is not too high, I think it still does not matter if it is not accompanied by alteration in the engine cooling sector.

In practice, the piston dome to be adjusted to follow the shape and close the valve openings owned vehicles. Usually given coak or special basin that follows the shape of the valve. This is necessary so that even when the piston is fixed TMA, do not hit the valve that is being developed or open. Some piston dome there that already have special coak this, but some of it should be made using the expression engine "milling" adjust the shape of the valve and open the valve far. When coak not made, the valve will hit the piston when the engine is operating continuously, the effect is very fatal, the valve can be broken, bent, etc., the piston could also cracked, broken, etc..