Hodgson Part 055, Heads

This entry is part 1 of 7 in the series Hodgson Cylinder & Heads

head80This page is one of the longest in the Hodgson Radial log and probably reflects that this is one of the most complex parts. I choseĀ Aluminum 7075-T651 for the head material and made a few changes to the process plan and the design of the head – most notably the method of retaining the valve seats. Follow along on this lengthy build log as I start construction of 11 heads.

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Hodgson Part 056, Valve Seats

This entry is part 2 of 7 in the series Hodgson Cylinder & Heads

seat16The Hodgson plans call for the valve seats to be made from Alloy 954 Aluminum Bronze (here in China this is called QAL 9-4 bronze or C63000 nickel aluminum bronze). These valve seats are retained in the head only by a 0.002″ interference press fit. Retention by only a press fit between components subject to heating and cooling cycles between two materials having different coefficients of thermal expansion is a problem waiting to happen in my opinion. I wanted a Continue reading

Hodgson Part 057, Head Gaskets

This entry is part 3 of 7 in the series Hodgson Cylinder & Heads

09-finished_ringsWell, it would have been nice if I could have found some soft 1000-series aluminum here in China so I could just turn and part off these rings from some round stock, but that turned out to be impossible. I ended up purchasing some 0.032″ 1100 aluminum sheet. 1100 alloy is essentially pure aluminum and the 12″ x 12″ sheet I ordered from McMaster (p/n 2471T11) was in the “0” (Annealed) condition – perfect for a head gasket.

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Hodgson Part 064, Cylinders

This entry is part 7 of 7 in the series Hodgson Cylinder & Heads

20-parkerizeOne of the biggest problems with trying to do something like the Hodgson Radial here in China is finding quality materials. I’ve been lucky with my aluminum products since there is a big Alcoa plant in Kunshan not far from where I live that supplies materials for both the China and worldwide aerospace market. Unfortunately I’ve not been as lucky finding a supplier of quality ferrous materials, and the purported 12L14 material I procured for my cylinders is a case in point. While I was assured this material was “equivalent” to 12L14, it was very gummy to machine and did not act at all like a free-machining leaded steel.

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