12-11-2018, 09:44 AM
(11-11-2018, 05:30 PM)Chris KC Wrote:(11-11-2018, 02:07 AM)Bob Culver Wrote: The centre bearing of the Seven dangles from the thin roof of the alloy crankcase so deflection under load must be significant. The mountings are frequently distorted out of static alignment which makes matters worse.
For sure chances of success are improved by isolating the crankcase from the chassis, one of the rear bolts should be left out or assembled only loosely. More extreme versions include sitting the crankcase of valve springs so it 'floats' above the frame. I can only guess the Lotus was engineered to do what was asked of it!
Another thing which helps is to chuck the Austin long centre bearing studs; a pair of inserts is put into the casing so the C/M can be screwed into the crankcase alone, with long 3/8" bolts, and thus divorced from the desire of the cylinder block to lift itself off.
Have used valve springs under tension to replace fixed bolts for many years — an improved oil feed to the centre main in conjunction with an oil filter is a feature of most engines assembled by Vince Leek and seems to make sense.
Charles