Assembling the short block - 1967 Rolls-Royce Silver Shadow engine

This shows the assembly of a short block at Robison Service, and some of the issues we have to consider when rebuilding these vintage motors. It's not as simple as "follow the specs" when the factory didn't follow them from the start, and 50 years later we have issues we can't readily correct, or which carry great risk of expensive complications. It's all about choosing the best path based on experience. Here at Robison Service we have been rebuilding Rolls-Royce V8 engines for 30 years and we've done quite a few in that time.

One of the issues we face is in the liners. We usually find the liners on older engines are protruding close to ten thousandths of an inch, which is more than would be acceptable for a newer engine running multilayer steel gaskets, but was apparently chosen by the Brits when they built these motors to provide more clamping force round the cylinder fire ring gasket.

For sealing against head gasket blowouts you want more liner protrusion. But as you increase the liner protrusion, the odds of water leaks from the corners of the head gasket increase.

You might think, why not mill them to an intermediate height? Sounds good, but to mill them, we would have to remove all the studs from the deck face, and that carries a huge risk of damage to those bores and thousands of dollars in work to repair the problem you just created, trying to solve the first issue.

But there's more! Instead of cutting the block, we could cut the tops of the liners a bit thinner. That is possible but if you cut the liner tops, you weaken them, and every bit you take off increases the compression in that cylinder in relation to the others (less smooth running). Furthermore, cutting the liners created potential unevenness across the head surface (potential for leaks), which we have milled perfectly flat in a separate operation.

Given those factors, and more I have not spelled out, each vintage engine presents unique challenges, which will be solved individually by machinists who do these old motors every day.

That is one way in which work on these cars is different from work on a modern car, even if the components look the same

John Robison