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Old 15th April 2022, 09:34
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Default Head Completed

I have now completed the dissassembly and reassembly of the head. It's now resplendant in MGB maroon which I understand would have been the original colour. Everything looked pretty good. The head has been gasflowed to what I suppose is stage 2. I am no expert but it looks pretty much as Peter Burgess describes in his MGB tuning book with the exception of hardened exhaust seats which it doesn't seem to have. Which leads me to think all the work on it was done many moons ago.
stripped_head by Robin Martin, on Flickr
reassembled_head by Robin Martin, on Flickr
During the strip and reassembly process I also cleared out all the waterways by blanking off the thermostat position and filling it with a solution of Rust Destructor and letting it soak for several days. It seems to have done the trick.
derusted by Robin Martin, on Flickr
While I was at it I also measured the combustion chamber volumes so I could work out the compression ratio.
combustion_chamber_vol by Robin Martin, on Flickr
Using the formula in Peter Burgess's book:

Engine size with +30 overbore = 1834cc. Cylinder swept area = 458.5cc
Combustion chamber volume as measured = 41cc
Clearance volume = 6.5 + 2 + 4.5 + 41 = 54cc
Compression ratio = (458.5 + 54) / 54 = 9.49

While I was at it I though it would be fun to work out the potential 0 to 60 time. Again using a formula from Peter Burgess.

0 to 60 = (2 x W / T) to the power of 0.6
W = weight – say 750 kgs = 1650 lb
T = torque – say 120 lb/ft (figure from Peter Burgess book for an engine with similar configuration)
0 – 60 = 7.3 seconds
So - no slouch then....

Cheers, Robin
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