Imp Heads Standard V Modified

After putting a standard Imp head through the Martins mighty mechanical saw, you can see there is room for improvement.
The ports closes right up around the valve guide, this is the same on the inlet ports also, incidentally if you have not already guesses by the carbon deposits these views are of the exhaust ports.
The sport head is a stronger casting with the water gallery's further away from the port allowing it to be opened up further with a reduced chance of cutting into them, but of course all heads vary slightly so there is still a small chance of disaster if opening them up to over 1.00"

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The Bevan head has George's trademark welded and drilled water galleries.
This is to prevent them collapsing as this can happen on heavily skimmed heads

My new race head
Started life as a rather grim head I got second hand, the valve seats and guides were shot and part of the combution chamber was missing exposing the wills ring.
Now back from repair by Martin the the chamber wall welded up and also the water galleries done and modified, pressure tested and new valve guides and seats fitted and matched. Head was skimmed and wills rings groves re-done.