Posted: Sun Nov 27, 2011 3:16 pm Post subject: oval pistons !!
Irealise I must be pretty gullible falling for this sort of thing but it is a challenge for my present therapist (Peter Scott) or any other kind soul prepared to minister to one of the Slightly Bewildered.
It has been put to me that such an engine was produced by a major player,namely Honda,whom I would have considered above such frivolous enterprises.Are any of the usual long suffering members aware of such a thing and,if so, the purpose?
My thanks in anticipation
Joined: 27 Dec 2008 Posts: 1116 Location: Chesterfield
Posted: Sun Nov 27, 2011 4:31 pm Post subject:
As far as I am aware ALL engines have oval pistons!
The cross section of a piston cannot be of equal mass or symmetry because of the gudgeon pin bosses etc.
Accordingly a piston made circular would become oval as it heated to running temperature. To combat this and make the piston circular when at running temperature they are machined oval on the opposite axis in the first place. It is not by much, but it is measurable.
As for Honda, they may have built an engine with visibly oval pistons. There are plenty of patented designs, most of which got no further, with strange (or even without) pistons. The * and jet engines obviously have no pistons. Renault also patented one in the late 1950s, but I do not know whether it was ever built.
This Forum keeps deleting a name spelt W-A-N-K-E-L where the asterisk is! _________________ Quote from my late Dad:- You only need a woman and a car and you have all the problems you
are ever likely to want". Computers had not been invented then!
Joined: 26 Jun 2008 Posts: 645 Location: Bothwell, Scotland
Posted: Sun Nov 27, 2011 4:50 pm Post subject:
In the quest for more torque Honda did make a oval/elitical piston bike racing engine but it wasn't a great success due to ring failures. It had two con-rods. VW also made a 2.3L diesel engine with oval bores again in the search for more torque and to get more displacement for a given block length.
Posted: Sun Nov 27, 2011 5:25 pm Post subject: oval pistons
My thanks to all my usual heroes,Jim,Penman,Art for helping me with their usual equanimity although I note the absence of my "shrink"".Perhaps the burden is getting to be a bit much and I can fully understand!
Posted: Wed Nov 30, 2011 7:04 pm Post subject: oval pistons
Good to know you are around and I reckon that this oval piston business seems to have been more in the realms of the Hairy Biker brigade and,therefore,not the sort of thing that well brought up gentlemen like yourself care to know about.
My thanks to the chaps who were ready and able to shine some light on what I, initially,believed to be nothing more than a test of my gullibility.
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