Jellybean Posted December 20, 2014 Share Posted December 20, 2014 Why do crankshafts use plain bearings instead of roller bearings Porsche used roller bearings in their 4 cam and Honda in thier 1964 SM600 Quote Link to comment Share on other sites More sharing options...
Benjy Posted December 20, 2014 Share Posted December 20, 2014 Because when roller bearings fail, they break up. Not only that, I've seen engines go for 500k miles. How many wheel bearings have you seen go that far? Quote Link to comment Share on other sites More sharing options...
pedrosixfour Posted December 20, 2014 Share Posted December 20, 2014 Not only that, I've seen engines go for 500k miles. But not the gearbox? Quote Link to comment Share on other sites More sharing options...
Dnk Posted December 20, 2014 Share Posted December 20, 2014 (edited) I'd have thought cost would have something to do with it Edited December 20, 2014 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
Benjy Posted December 20, 2014 Share Posted December 20, 2014 No. Never seen a box do 500k without a rebuild. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 20, 2014 Share Posted December 20, 2014 The Honda S800 sports cars used roller bearing cranks, both for mains and big end. I used to specialise in these and had dozens through the workshop over the years. But you have to consider how to fit them. The Honda used a press together crank and needed splitting and re-aligning to fit them. Split cage roller bearings exist, but are not technically suited to that sort of application. The 1966 S800 was a four cylinder, all aluminium ally unit, that revved to 8500+ and the engine was a stunning creation on quad carbs, twin cams, with a centrifugal AND a paper element oil filter. Lovely jewel like things. It was heavily slanted to keep the C of G very low. http://en.wikipedia.org/wiki/Honda_S800 Quote Link to comment Share on other sites More sharing options...
Jellybean Posted December 20, 2014 Author Share Posted December 20, 2014 Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 20, 2014 Share Posted December 20, 2014 Wonderful, that takes me back! I scrapped about 15 of them for spares, the UK owners club had a love / hate relationship with me, but came knocking for bits The S*800* wasn't chain drive, it was a conventional prop to a rear diff and live axle. A lovely time, I so enjoyed working on them, the engines especially. I still have a brand new head gasket and a part engine gasket set in the shop, and two very rare sets of OE shop manuals and parts manuals. I even sold an S800 to an ex girlfriend. She drives a Ferrari now, in Florida, but I bet it doesn't sound any nicer than the S800... Right, I have finished my nostalgia trip, thanks for finding that video Quote Link to comment Share on other sites More sharing options...
Jellybean Posted December 20, 2014 Author Share Posted December 20, 2014 Taught you might like it Quote Link to comment Share on other sites More sharing options...
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