Work has continued on the engine, with a few quieter days off over Christmas/New Year coming in handy.

The cylinder head has been completely stripped, cleaned and valve guide clearances checked (head face to be skimmed still). With the head off, it was also the perfect opportunity to stick the head on a CMM and record all the relevant information required for cam design.

The exhaust valve guides show a little more wear than the inlets (less than half a thousandth of an inch), but all are within tolerance and should be good for a fresh build.

Taking a closer look at the throttle bodies it can be seen where BMW have ported the butterfly and head ends of the casting, but the middle is left as cast. This isn’t a massive problem, as the surface roughness in this area is probably quite good pre fuel injection. However, there’s obviously a little bit of mis-allignment in the castings as all the throttle bodies have an edge running down the sides.

Inspecting closer there was a few other areas that could be tidied up, so some time was taken (it takes around an hour per body) to blend the surfaces inside. The surfaces were deliberately left a little rough to help build a turbulent layer which should aid fuel/air mixing.

On the development front, things are progressing well towards the new cam. It’s quite obvious additional lift won’t be possible without changing springs, but considering the valve sizes it’s unlikely additional lift will improve flow dramatically (KED Engine #2 pictured).

New cams will be manufactured from scratch, so a full drawing of the shaft itself is required. This is now 99% complete..

Next on the list is to rebuild the Vanos and push on with the cam design!

 

KED Build #001 (S54B33)

• Introduction
• Part 1
• Part 2
• Part 3
• Part 4
• Part 5