Axleboxes, crosshead slides and crank bearings all suffered due to the high speeds.

The crank bearing is also regreasable.

He can not see the rings or the valves or the crank bearings, yet he is expected to make a judgment on these items and their condition.

Internally, the engine received split crank bearings instead of the C50's one-piece bearings, as well as slightly modified valvetrain components, which necessitated modifications to the cylinder heads.

This modification, along with the use of larger crank bearings with main bearing caps reinforced by a rigid ladder-type main cap girdle to allow the engine reliably rev to 7500 rpm.

Crank bearings (remember the crank was still in perfect condition) and big end bearings are all new, and again to maximise performance and durability we went through the process of sizing every bearing.

Belliss and Morcom developed a two-cylinder engine of 20 bhp at 625 rpm that used a small separate oil pump to feed oil under pressure to the crank bearings, through long drilled holes in the crankshaft.

As engines were adapted for automotive and aircraft use, the need for a high power-to-weight ratio led to increased speeds, higher temperatures, and greater pressure on bearings which in turn required pressure-lubrication for crank bearings and connecting-rod journals.

Instead of using the usual two-piece crank bearings, one-piece items were pressed onto the crankshaft with a hydraulic press once the crankshaft had been submerged in liquid nitrogen to cause it to contract (thus providing enough clearance to press the bearings on).

Some engine makers, such as Robey & Co. of Lincoln, developed a distinctive form of cantilevered cast iron bed for their large medium speed engines that formed both the crosshead trunk guide and the crank bearings, thus permitting a similar single plinth foundation.