Friday, September 11, 2009

"Piston Besar"

The meaning to my title in English would be "Big Piston". These days it is quite common to use Ford original pistons especially the 83mm for the Honda B-series B16a/B18C and also the Mitsu/Proton 4G9X. Ford has the 83.5 oversized pistons and also another brand for Ford engines which is the 84mm which is commonly used by the Honda B20VTEC hybrid project.

This would be the bang-for-the-buck pocket rocket formula but the RISK is in the owner's hand. Typically the Honda/Proton block will be bored from 81mm to 83mm to fit the piston. The piston is then machined to fit the rods and prolly some custom job for deeper valve relief to suit the camshafts. No resleeving talk here.

Quite recently, people start to resleeve their blocks with local aftermarket sleeves to fit bigger pistons. No doubt there is a bit of cost there but at least it is safer than the common method. Long lasting gurantee, i wouldnt know unless its a bullet proof iron ductile sleeves that makes you sleep soundly at night. Unless i said.

The 2nd photo is the 4G93 block with the 83mm pistons hybrid with a 4G92 Mivec head. With a 1.9xxcc, fatter torque and higher compression you can definitely feel the power with this combination.

These pistons are awfully cheap than aftermarket pistons. People tend to resort this way due to the cheap and quick power. The long term and sometimes short term consequences are sometimes forgotten. Good tuning is compulsary at this stage.I have heard plenty of horror stories of engines failures from detonated cooked pistons to cracked sleeves due to the heat generated from the thin walls.

I have also known a few chaps that still runs with the 83mm after few years of using it with a strict discipline plus a light footed driving style that managed to survived till today.

The rest of the misfortuned as usual, rebuilt and sold their cars.