slowsteve. You sounds like one hell of a model engineer. I can calculate that as I have been practicing model engineering for a very long time, have what can be called a well-equipped home model engineers workshop and been around dialogued with seen the work of very well established model engineers of great achievements. But this here Mad Scientist sounds like a real Grande dreamer.SlowSteve wrote: ↑Tue Aug 05, 2014 9:39 pmMad_Scientist
I make a lot of engines - i.e I start with pen, paper and blocks of metal, lathes and Mills and after lots of cursing out pops an engine. I have worked with a lot of materials, including all of those you list in your first post, and used them all in engine builds.
I would say that I am fairly good at it - I can make a steam engine which handles a measurable 17,200PSI of chamber pressure, I can make 2 strokes which deliver 23,000 RPM and I can make fully functional minature jet turbine engines which will fly a hefty model - all of them on my own and starting the designs from a blank sheet of paper. I don't say this to show off - I say it to show you that I'm not an arm chair engineer and I'm here to help if you need it.
With that background you're comment about "I don't really worry about compromise" and "I understand the differences in thermal expansion and it's easy to over-come" suprised me a lot - either you are a genius who makes me feel stupid - because compromises and fit are two of the banes of my life - or you are about to spend a lot of money on something that will cause you a lot of swearing, or worse be flat out dangerous.
If you have the engine block, then a lot of your decisions have been made. Your bore x stroke is pretty much set. Your bearing points and bearing layouts. Your studding patterns. Your crank shaft lay out. This in turn will affect your valve choices, your lubrication choices..... etc etc etc
If you're block if fixed, then the question that you should be asking youself is "What do I need to do to extract the maximum power from this block". Then "What is the maximum power this block can handle" is the next question - which is a different question - you don't say anything about the block you have but, for example, a LOT will be determined by the webs around the shell bearings - you can use any material you like, but if there is a harmonic issue, you you just don't have enough meat in them to support the bearing torque, then the engine will pull itself to pieces even if you use the finest materials in the world. "Materials science" is NOT "Engineering". You're asking "Engineering" questions but looking for Materials Science answers.
If you want us to shout out the names of some funky materials then we can do that. tell us and we will provide you with a list of wonderful gubbins in the blink of an eye.
If you want actual input, then also shout out and we will try to add value and usefulness.
If this is just mental excerise, then all power to you.
But... please please please don't be in a position where you are spending your own money on this and asking questions like you are.
Aluminum beryllium use in engines. At around 1968 when Porsche produced the 917 flat 12 they had already been the first ever to produce aluminum beryllium pistons, they produced these pistons for an undisclosed eastern military block, but when it came to use them on their own 917 flat 12 they didn’t even dare ask for the go-ahead from the Volkswagen board as they calculated that a set of 12 pistons costing more than the than average road going car would not be approved. Later on Osamo Gatto at the time at FERRARI F1 was the first to suggest to Brembo the use of aluminum beryllium for their brake calipers to achieve the need of stiffness they required.Tommy Cookers wrote: ↑Fri Nov 06, 2015 12:15 pmit seems that last year some posts here were contributing to the mythification of engineering materials containing beryllium
there is no particular hazard with established materials, since the beryllium is a tiny % dissolved in the major constituent
only surface scale (from heat treatment in air) has any hazard potential
copper beryllium aka beryllium copper is the outstanding valve seat material for straightforward reasons
it is a very strong material with a rather low Elastic Modulous and very high thermal conductivity
it is simply what was non-mysteriously known (in the UK anyway) as beryllium bronze
(though bronze seems to be a non-approved term these days eg even archaeology & history's 'bronze age' has disappeared)
also it's the outstanding spring material (if weight is unimportant)
for a given elastic limit strain ('springiness') it will be less difficult to machine than more conventional alternatives
and (at a lower beryllium content) is the best material for many electrical connection/contacting purposes
totally unlike materials around 35-60% Be/65-40% Al etc such as were briefly used for F1 pistons until banned by the freeze
pistons whose life was 2 hours
I suggest none of us has even seen any such material, and have not worked on it or used it in design
its fatigue life/low-temperature brittleness tendencies (and toxicity) have prevented its establishment as an engineering material
even in aerospace, except in vehicles that are literally 'one shot'
its attraction for 94 mm 20000 rpm pistons might be the synergistic combination of low density and remarkable thermal conductivity
(otherwise its outstanding specific stiffness)
it might be viable as an extremely expensive way to a lighter cylinder head
magnesium alloy (as a post recommended) is poor, being too weak to hold valve seat inserts unless very thick
(though a 7000 series Al alloy might not need any inserts - Repco tried this with a conventional alloy for their AusRover V8)
no secret ....
an important use of Be was in H-bombs as an engineering ingredient that helped (not hindered, as others would) the nuclear reaction
Porsche used some largely-Be alloy for brake discs (before vented discs existed ?) in the 60s at Le Mans etc
they would have a uniquely advantageous combination of very high specific high heat capacity and thermal conductivity
this source is a good read on beryllium and the industry (thanks, Google)
https://books.google.co.uk/books?id=3-G ... um&f=false
and this from the trade (no personal connection)