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Model 25 conrods - and socks!


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I have a 1916 Model 25 which is slowly undergoing restoration/rebuild to be a speedster.  The engine was complete, had compression and looked to be OK - but I thought I'd at least drop the sump and have a look inside before trying to start it.  My first discovery was a sock inside it! A black one. Unfortunately only one, so not a great deal of use for its intended purpose. How on earth did it get there? This did make me concerned enough to get a torch and look up the bores, at which point I couldn't be quite sure what I was seeing so removed the head and extracted the pistons/rods.......................


At some time in the past someone had fitted aluminium pistons, which had a slightly higher crown height. The solution to this was, to put it mildly, novel.  All the conrods showed signs of heat and had a "bulge" about half way down. It would appear that they had been put in a press, heated and then "squashed" until they were the correct length.  If I could post a photo I would.  Whoever did it, presumably a blacksmith with large muscles and small brain, was skilled at what he did - every rod was true with aligned big and little ends which is quite an achievement.  The pistons were new, so it would appear it was never run subsequently.  Opinion was split about 50:50 amongst those I asked (including a couple of metallurgists) as to whether it was safe to use them but I thought it too much of a risk so replaced them.  I've never seen the like before.

Edited by pvmw (see edit history)
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    Take out all the spark plugs and turn the engine over  slowly, if it turns freely and you have compression on all cylinders you should be OK.    The sock might have been used to plug the oil filler tube at one time.   Let me know how you come out.



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