[QUOTE=1929;1046986]
what has the better advantage? is it true that with babbitts the head should be no more then a 5.5. If you are going to rebuild your motor, why not go with inserts even if it costs more.[/QUOTE]
Our personal opinion is that compression ratio for babbitt is to 5.9 to 1 as "Brumfield heads" are designed to that spec.
The better advantage is babbit since it's ability to ingest dirt and not damage crankshaft journals also the benefit of years of adjustment to the bearings, whereas if the insert is damaged then time for a rebuild.
The first two pictures show a poor job at insert bearings and you can see they're torn up from residual grit left in the engine at 200 miles.
Also I have enclosed our babbitt as a finished example.
Last pictures shows the dirt impregnated into a Model T babbitted bearing again recently done but engine was still functional due to the principal fact that babbit eats dirt. This according to customer was at 5000 miles.
These are two examples babbitt versus inserts though both poorly done but show the features and results of both.
Most recent example was
Seth Kestenbaum's 1929 engine still had original babbitt and I was able to grind his crank to 10/10 with room to spare. This engine hadn't been rebuilt and was hardly taken care of.
This engine is 86 years old in the contest of durability it is by far Babbitt the clear winner.
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