Re: 40 MPH Club
So far the China girl engines have withstood over 13000 rpm in one build, the Arrow race engines make nearly 10hp... and some are modded to make even more at 11000 rpm and the strongest China girlnive seen so far was making a claimed 18 Hp at 13000 rpm using a stage6 jug for a malossi enngine so these bottom ends are proven as long as the work is done right, it looks like they will hold just fine... I'm sure there is a limit to the power or rpm where one would throw a rod but so far the only ones that have toasted were mainly from taking too many shortcuts or using cheap internals like the original bearings or the older type rods that used the un caged needle rollers and no real way tonget the oil into the bearings except for a few small grooves on the side of the big end for oil to make it to the rod bearing.
The better rods will have 3 or more oil holes on the big end or a long open slot for the oil to get to the bearings on both ends.
Also a nice true crank with a welded in pin will add to the durability as well as better crank bearings....
My first engine had toasted cranknand clutch bearings after only about 90 minutes total run time. The rod has no oil holes on the small end and none on the big end either... just a few grooves on the side of the rod so it was a good thing I decided not to use that crank setup after seeing the poor quality of everything.... the Dax bottom end I'm using now has nice oil holes on both ends of the rod, the good bearings already installed and a caged rod bearing... perfect for some trouble free upgrades.