The new 152 con-rod has been designed specifically to go with our new 2-litre Duratec slipper pistons, it is 6mm longer which has helped to reduce the rod angle which in turn helps to increase the torque. On our high spec engine we saw an increase of 6lbft torque & just reaching 200lbft torque. Due to the smaller pin size on the piston, this has reduced the weight of the small end of the rod which means the rod is actually 12g lighter than our normal Duratec rods. We have also upped the rod bolts to the ARP625+ high spec material to cope with the extra performance.
This design of rod has several improvements which benefit the engine. There are two vertical grooves on the side of the rod, this directs the oil spray as it exits the big end vertically upwards towards the pin and the crown of the piston,. This has two benefits, it helps to supply lubricant directly to the gudgeon pin also the cool jet of oil to the underside of the crown of the piston helps to reduce the temperature of the piston itself. On the small end, we have repositioned the oil hole which feeds the small end bush. This is because the one at the top which is normally used effectively weakens the rod itself which increases the possibility of breakage when the rod is brought down by the crankshaft. By moving the oil hole to the side of the rod, there is far more material in this area to help maintain its strength.
Because of the above modifications it is no longer necessary to supply an oil feed through the bearing, even if your bearing still has a hole for the oil jet, it does not reduce its improvement, the hole is simply filled with oil and the pressure in this area is maintained.