On the subject of HP loss between '66 and '74 MGBs, I suspect that the
single biggest factor is the exhaust manifold with bolt on
catalytic converter, a very inefficient design. The early manifold
was actually a crude implementation of a long center branch header,
designed to work well with the siamesed exhaust port for #2 and 3
cylinders. The one piece intake/exhaust manifold which replaced
it in 1974 looks like it was deliberately designed to keep the
engine from breething properly.
When I converted to SUs (HS4s), I used a pre-74 exhaust manifold the
improved breathing on intake and exhaust made a remarkable difference
in the car's performance.
Peter Schauss, Long Island, NY
ps4330@okc01.jccbi.gov
schauss@worldnet.att.net
1963 BJ7
1980 MGB
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