Olive Branch, MS: In February, 2010 Lunati unveiled six new Pro Series stroker crankshafts for the LS7 with stroke lengths of 4.325in to 4.625in. This year they have concluded the range by adding a further four. American-made the stroke lengths of these new crankshafts are as follows: 4.000in (P/N: JO711ER); 4.125in (P/N: JU711ER); 4.185in (P/N: JL711ER); and 4.250in (P/N: JP711ER).
Earlier, Lunati introduced ten stroker cranks for LS1 engines. Both series of cranks (LS1 and LS7) encompass stroke lengths of 4.000in to 4.625in and feature conventional 2.559in main bearing journals and 2.100in rod bearing journals. OEM rod lengths of 6.125in are recommended on strokes from 4.000in to 4.185in., but on the remaining longer strokes, from 4.250in to 4.625in., Lunati recommends 6.300in connecting rods for a better stroke-to-rod ratio. All of these cranks are now shelf-stock items.
In addition, Lunati offers custom grinds to any dimension within this stroke range. Furthermore, custom grinds can be obtained with either standard crank pins (2.100in) or with larger big-block-style pins (2.200in), which adds durability to engines with power adders.
Using American-made premium 4340 steel forgings these cranks are capable of handling 1,500-plus horsepower. They are endowed with micro-polished and lightened connecting rod journals to reduce rotating mass, micro-polished and gun-drilled main journals to reduce overall mass, special counterweight profiles to direct oil to the bearings and reduce windage, and Lunati’s exclusive finite detailing, profiling, and pulse-plasma nitriding processes. The latter provides consistent journal surface finish without affecting core hardness.
Lunati’s long-stroke cranks are in stock and ready to ship.