Cast Iron VS Aluminum BLOCKS
#46
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Originally Posted by SaabTuner
However, Beryllium is both toxic and extremely expensive. It's toxicity is similar to that of asbestos and, at nearly $400/lb, pure raw Beryllium is more than 60,000 times more expensive than pure raw Aluminum. So using the Beryllium/Aluminum alloy, or straight Beryllium, probably won't happen in a production car in the near future ... or at least one under the $200K mark.
But you're right, I don't think we'll be seeing them in road cars any time soon. Which is a shame...
#47
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Originally Posted by Shaun@SG
There was brief experimentation with MMC and the press got over enthusiastic with their reports. For a long time they were reporting weights of experimental pistons that were never run in actual races.
Thanks for the inside info nonetheless.
Looking over the F1 regs, there are still a couple interesting things I noticed: 1) intermetallic compounds, like Titanium Aluminide, are now banned and, 2) Oxide Dispersion strengthened alloys are not banned despite being MMC's because the F1 regs define MMC's as having more than 2% unsolubles. Oxide Dispersion strengthened alloys like this one or this one offer significant increases in strength over even the best Inconel/Nimonic/Waspaloy alloy currently on the market at temperatures exceeding 1850*F or so; they're especially usefull for engines attempting to run over 2000*F. Unfortunately, I cannot find any source for the EGT's run by Formula 1 cars, so I cannot even begin to assert if these alloys would be remotely usefull.
Still interesting stuff. Sorry for the OT, everyone.
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Originally Posted by x838nwy
I thought Beryllium i only toxic when machining but not toxic in stable form (like as a finished piston). I can't see it being that hard to equip a lathe with a shroud and a suction fan and filter etc. Most of the cnc machines have this anyway so I wouldn't think toxiciity makes that much of a difference, unless you're machining them manually.
But you're right, I don't think we'll be seeing them in road cars any time soon. Which is a shame...
But you're right, I don't think we'll be seeing them in road cars any time soon. Which is a shame...
If more Beryllium mines open, you might see widespread use of it in high hp/displacement engines, but I think you'll see a trend towards carbon and ceramic piston materials instead.
For sake of comparison, Dow Corning's ceramic Silicon Carbide (SiC) fiber, Sylramic™, has a tensile strength of over 3,000 MPa's. That's more than 5-times stronger than optical grade Beryllium at around 550 MPa's and comparable in density. It's thermal conductivity is lower than that of Beryllium, but it is still on par with Aluminum, so no loss should be seen there.
Also, as another total tangent, NASA did some cool work with Dow Corning's Sylramic™ fiber; they found a way to relieve the boron which forms in the fibers and bring it to the surface in a controlled nitrogen atmosphere where it forms a boron nitride coating which is highly oxidation-resistant. The new fiber has been re-named as Sylramic-iBN™. Very interesting stuff. At 1400*C (2552*F) the Sylramic-iBN fiber will still survive a 100 hour rupture test at 500 MPa's. That's a high enough temperature to melt many steels, even certain grades of superalloys. Here's a page on it if you are interested: Sylramic-iBN™
w00t for NASA!
Last edited by SaabTuner; Dec 28, 2005 at 05:38 PM.
#49
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getting waaay off topic
Cheers for the info, they look like really amazing materials indeed. I don't think I'll ever get it through the powers that be around here to use in our machines though. I'm still trying to convince them to use Ti-alloys, let alone Sylramic!!
And that's the sad reality of it. Most people in the world will never benefit from these wonderful developments in materials. If they don't get put to good use by mass production (to reduce costs) you're not likely to see them around in 50+ years.
SaabTuner, what line of work are you in? Seems very knowlegable on this sort of stuff. Since I've been working in the real world, it's mainly steels so I'm a bit out of date....
And that's the sad reality of it. Most people in the world will never benefit from these wonderful developments in materials. If they don't get put to good use by mass production (to reduce costs) you're not likely to see them around in 50+ years.
SaabTuner, what line of work are you in? Seems very knowlegable on this sort of stuff. Since I've been working in the real world, it's mainly steels so I'm a bit out of date....
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Originally Posted by x838nwy
Cheers for the info, they look like really amazing materials indeed. I don't think I'll ever get it through the powers that be around here to use in our machines though. I'm still trying to convince them to use Ti-alloys, let alone Sylramic!!
And that's the sad reality of it. Most people in the world will never benefit from these wonderful developments in materials. If they don't get put to good use by mass production (to reduce costs) you're not likely to see them around in 50+ years.
And that's the sad reality of it. Most people in the world will never benefit from these wonderful developments in materials. If they don't get put to good use by mass production (to reduce costs) you're not likely to see them around in 50+ years.
That's actually why I never criticize wealthy people for buying expensive cars or private jets. When they do, they give other people jobs building those things and, sometimes, the technology in them filters down to the rest of us. It's like an investment in new technology, and that's a good thing!
SaabTuner, what line of work are you in? Seems very knowlegable on this sort of stuff. Since I've been working in the real world, it's mainly steels so I'm a bit out of date....
Anyhow. Knowledgable or not, I do like to share whatever cool things I find. And this is hella cool --> NASA turns wood into high-temp SiC ceramic.
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I suppose cf and its various derivatives have come a long way, and it's a good thing. But imagine super light engines and transmissions (thus more efficient) in everyday cars. The increased performance means they'll be more fuel efficient and more reliable from the reduced weights. The only thing it takes is a HUGE investment which should be in the interest of car manufacturers since the use of these materials will be more relavant into the days of alternative fueled vehicles. It doesn't look like we're going to come up with anything near the energy density of gasoline any time soon, so it would be a good idea if we can stop lugging around tons of steel everywhere we go...
#52
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Well, I think to sum up what weve discussed so far, cast iron blocks tend to be the choice for high cylinder pressure applications, but aluminum can work well if done correctly- as witnesses by the incredibly successful LS1, the old cobra engines, ford GT, and countless othe exotics.
No matter the material, I think the overall "strength" of the next evo block will be less affected by the material choice and more affected by the way in which MMC appraches the design of the next evo. What I mean by that is if Mitsu decides it wants to make the car lighter and cheaper at the cost of part strength, the block (along with many other things) might suffer....kinda like what Nissan did when it went from the 300Zx to the 350Z.
No matter the material, I think the overall "strength" of the next evo block will be less affected by the material choice and more affected by the way in which MMC appraches the design of the next evo. What I mean by that is if Mitsu decides it wants to make the car lighter and cheaper at the cost of part strength, the block (along with many other things) might suffer....kinda like what Nissan did when it went from the 300Zx to the 350Z.
#53
Cast iron is not only the choice for high cylinder pressures, but also for high RPM and/or large rotating/reciprocating mass engines.
I can assure you that the aluminium 1000 hp LS1, if stock sleeved, was suffering terribly even under limited duration use. Ideally every power rating should be accompanied by efficiency and service life figures. If referring to stock LS1, it is a very unstressed engine.
I can assure you that the aluminium 1000 hp LS1, if stock sleeved, was suffering terribly even under limited duration use. Ideally every power rating should be accompanied by efficiency and service life figures. If referring to stock LS1, it is a very unstressed engine.
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