[Healeys] 100 Block

[John Harper]

Rich

Yes this is an A90 Atlantic block. Most Austin 16,  A70, A90 and 
commercial 2.2 litre 4 cylinder petrol engines had only the one fixing 
bolt up until about 1952. A few A90 cars had two bolt fixings before 
production ceased but the majority had only one.

A single bolt might legitimately have been fitted to a 100 because BMC 
sent out some reconditioned 100 engines with single bolt blocks. They 
produced a service sheet to explain how an extra hole could be drilled 
in the mounting distributor mounting plate. I believe that an extra 
spacer ring was required. If anybody is seriously interested I could dig 
out the service sheet.

However it is more likely that an A90 engine acquired locally would have 
been fitted.

I can quite understand why this modification was done. I had a 
distributor 'jump' out of its clamp on a long drive south in an A70 
nearly 50 years ago. I had to retime it on the side of the road by trial 
and error.

I still have 2 worn A90 Atlantic half engines but when I mention the 
distributor issue people loose interest.

Best regards


>Speaking of differences in Hundred engine blocks, I have a customer's
>Hundred engine here that has only one distributor clamp mounting hole,
>instead of the usual two. When looking at the distributor side of the engine
>there is the hole for the distributor body and only one threaded hole
>located just aft (to the left of) the distributor. Has anybody else seen
>this arrangement?
>
>Rich
-- 
John Harper