Re: straight 8 engine

Posted by Tim Cole On 2012/9/29 16:34:36

Technically there isn't one given the motor is free wheeling. In an interference engine going past redline can result in the valves hitting the pistons.

That said, the service letters indicate maximum speed for the eights in the 4200-4400 rpm range.

Given the proving grounds opened in 1929 the standard axle ratios no doubt were chosen for highest top speed.

In 34 they ran a V-12 wide open for 6300 miles when it blew up. Later with insert bearings they ran an Eight 15,000 miles wide open and found the bearings still within tolerance. However, those crankshafts wear out so running those motors like that today will blow them up.