I remember reading about conrods made this way back in the 1970s. This was (from memory, never a reliable resource) for Mercury outboard engines made in the USA. These were two-stroke engines, needing roller big-ends, and the cracking idea allowed assembly onto a one-piece crankshaft rather than the traditional way which used built-up cranks. So, well done the Japanese, for re-discovering a technique and (I am guesssing) applying it to four-stroke engines too. In this application, the cracking technique should eliminate any tendency for the two halves of the rod to shuffle at high revs, and so extend the life of the bearings (etc).

And of course, it prevents the village craftsman filing the ends of the rod to take up the, er, slack, when rebuilding an old engine. They didn't used to do that, did they grandad? Wasn't that a bit naughty?

Regards, Tim

What happened to my post?

They were patented in 1951 and have long eben used in performance cars, but apparently they are now becoming more common in ordinary ones.

Neil

Well done Vic, really interesting, the company I worked for had a rolling mill in darlington [darlington & simpson rolling mills rise car darlington] when we did work there we used to watch the blacksmiths making tongs/tools for handling the rolled sections,I still have a couple of pairs that I use in my foundry. The roll turners had lathes that they knocked wedges in to feed the tool in to turn the rolls instead of handwheels.

I thought Peugeot used such rods.

JA

.

Was was watching a doc only last week of them making the new(ish) Corvette Stingray. They were cracking the conrods on the engines for those.

Nick

Edit :- Had a look to see it it was on youtube. It was. Go in to about 6 mins 20 secs.

Edited By Nick_G on 12/12/2016 19:50:09