Get your Essex V6 ready for assembly
Make sure all your new and machined bits fit together perfectly
In the previous instalments of our Essex engine rebuild, we stripped everything down then measured and inspected all the key components to see if they were within the tolerances stated in the manual. This left us with a shopping list of bits that needed replacement, a pile of bits to reuse and a pile of bits that needed machining. We gave the latter pile a rudimentary clean and carted it to a machine shop – in our case Owlesebury Crankshaft Service in Winchester (ocservice.co.uk).
OCS started by carefully measuring all of the components and checking the availability of the oversize/ undersize parts required. The key reason for having the block machined is to remove the wear in the bores by machining them oversize to accept larger pistons. To finish off the block work, OCS pushed out our worn camshaft bearings and pulled in new ones, and refaced the cylinderhead faces. The crankshaft was ground undersize, polished and balanced. The cylinderheads were completely overhauled.
OCS was able to source pistons and rings, valves, valve springs and all of the bearings. The other parts we bought from various Essex suppliers. Some standard bits are obsolete and only available in uprated motorsport-oriented form. One case in point is the camshaft. However, Newman Cams
(newman-cams.com) was able to help by grinding a blank to the original specification for less than a readily-available ‘hot’ version.
Burton Power (burtonpower.com) has a wide range of standard and uprated parts, and supplied things such as our pushrods and cam followers. Everything else came from Car Clinic (essexengines.com), which holds a large stock of standard and modified spares and can machine various parts on a mail-order basis.
In this instalment, we’ll guide you through the process of checking the tolerances between the new and freshly-machined components. This isn’t to question any of the machining work carried out or the quality of the parts supplied. All parts are made or machined to a tolerance. It’s not inconceivable that if mating parts are at the extremes of these tolerances, an assembly could be either too tight or loose. It’s highly unlikely that you’ll have any problems, but it’s best to find them now than later on.