Reading an old artical on offy's from the 60's and they mentioned some teams were testing magnesium Pistons for indy the next year but having a hard time getting them to go the distance. Has anyone heard of them being successfully used??
Cylinder temp is not Supposed to reach that hot, it has like a 800 deg burn temp and i've actually seen some brake disks made with the stuff as for brittle, a lot of HD stuff was/is made from mag like rear pumpkins and wheels
800? Thought it was more. but anyhoo , wheels and diff. aren't exposed to explosions most of the time. Sounds kinda crazy to me.
I worked for Porsche years ago and they had a parts warehouse in San Antonio, I think on NE loop 410, anyway, something caught on fire in the warehouse and soon became and all out conflagration. At the time, engine cases and trans cases were made of magnesium amongst other parts. Apparently these parts caught afar and when the huge pumper trucks arrived they started pumping water onto the blaze. To their suprise, it made the situation worst. By some accounts, it was like pouring gasoline on it. It wasn't until foam trucks from a nearby Air Force base came that they were able to bring the disaster under control. As for as I know they (Porsche, Audi, Mercedes, VW) never reopened the parts distribution warehouse, it was a total and complete loss. I don't know the point at which a magnesium part will burn, but it will. And when it does you have Hell putting it out. I know exhaust valves and headers glow red and aluminium pistons will get hot enough to burn holes in the tops of 'em, how hot is that?
Pure aluminium melts at 1200*F, don't know about the alloy they use in pistons. Magnesium slugs just sound like a problem waiting to happen to me
In the 80's I was a volunteer Firefighter/EMT out west. We went to a outbuilding on fire early one morning. No electricity to it, just a shed , about a 12X12. Fully involved (on fire). We rolled up on the scene, put the truck in pump gear and proceeded to put the wet stuff on the red stuff so to speak. Immediately a LARGE bright white flash. Shut the nozzles down immediately as we wondered if we had underground electricity to the shed, but uncommon as the adobe soil was like rock to dig through. The previous owner of the house (we found out from the new owner) died and left behind a large collection of small engine parts that the new owner had not disposed of yet. And apparently a lot of them contained Magnesium. And when Magnesium burns, it burns so hot that water breaks down into Hydrogen and Oxygen, both fuels for the fire so to speak. We protected outlying structures and let it burn itself out as we didn't have any foam suitable for Magnesium fires that night.
Google is your friend. http://www.metsoc.org/virtualtour/processes/maginfo.asp The use of magnesium components in the automobile industry is not new. In 1921, Tommy Milton won the Indianapolis 500 at the wheel of a Frontenac equipped with magnesium pistons. In 1926, Elektronmetal Cannstadt began producing die-cast magnesium pistons of which 4 million were on the market in 1937.
Magnesium burns at 883F in air. Cylinders temps are well over 1000F. Sounds like an issue unless they were coated in some way.
i used to work in a magnesium extrusion and fabrication plant, and one of the reasons why mag wasnt used for a lot of things was it corroded at a much faster rate than aluminum. although some alloys are much stronger and lighter than aluminum alloys, the parts just would not last because of this.
When I was an apprentice machinist,(a long time ago) in the Foundry, we poured aluminum at 1800 degrees. when I was in the Navy if a helicopter went down in the ocean you had to get it out within 20 minutes, because after that, the considerble amount of magnesium would start to return to the Sea, where it came from. When it starts on fire, all you can do is contain it, you can't put it out. When machining it we used to have a bucket of sand close by, just in case. and, I think you will find that the compression ratio in 1921 was probably about 5:1.
in 1961, we made 3/8" X .030 magnesium tubing pushrods for Jerry Castro's Sprite, which at that time was arguably the fastest in the world.
Rumor was when Greg Anderson was killin em in pro stock a few years ago, a lot of the engine moving parts were of a extremely strong, featherweight material (beryllium?). Supposedly lighter than mag,much stronger,but a major health hazard. It was said NHRA couldn't figure what his edge was, had WJ look at pieces at a teardown and he told em what was going on. Just a rumor, but I heard it from 2 or 3 sources completly independant of each other.
I had to tear the Sprite engine down, at Laguna Seca after he won a race, and when I pulled the Pushrods and the lightened lifters, the tech guy had no clue. The pushrods were so light, you felt like they would float away.
I'd be willing to bet all the money in my billfold ($3) if a modern TFD used pure magnesium pistons on a typical pass it wouldn't last 60 feet, if that. It has been estimated the flame front using 95% at 1.7:1 air fuel ratio is over 7000 degrees F Damn right they'd come out the pipes.
They'd be a blast in a turbo application. Talk about detonation! At Bonneville they have a Magnesium bonfire!
Magnesium pushrods are one of those ideas that sound great and don't work - no stiffness to weight, plain mild steel is far better. I beg to differ with you. They do work, but probably would not hold up to the conventional wisdom of huge valve springs and lots of recpricating weight. when we used them, we also reduced the weight of the valves, the rocker arms and the tappets to a bare minimum. that engine would spin close to 9000 rpms, and never bent a pushrod. in fact we never had any trouble with it at all.
100% correct. We will be seeing alot more Magnesium used in future engine design because of tests and studies done on numerous thermal coatings in recent years. One such coating is called Keronite, an aluminium based material which has all the advantages of protecting an Magnesium piston against all the elements and barriers such as heat, corossion, etc. Tests have shown that a treated part can withstand temperatures of 1000 degrees {1832 degrees F} Another advantage a cast Magnesium piston has over other metals is the weight savings. Even the conrods would not have to be strong. Aluminium valves could even be applied to engines. Diesel engines already use this technology for the combustion chambers. The list goes on. As to using Magnesium pushrods, that would be left to the American OEM's to design and overcome since they are the only manufacturer's still using an antiquated engine design. There was talk many years ago that the late Keith Black had a stash of Magnesium pistons. Is there any truth to this rumor? Just wondering.
Y'all think that aluminum was alloyed with magnesium in 'magnesium' pistons? I've heard that early magnesium wheels were alloyed with aluminum as well.
Aluminium valves. Have another read. As to calling American's foolish, you said that. Keep your money too. I'm not here to argue but only to dicuss.
I would find it hard to believe pure magnesium would work in any instance, much less a "racing" piston, which this thread was about.
Magnesium, beryllium, etc. HAVE to be alloyed with another element to be stable. In their pure forms, if they are exposed to water, etc, you get what the fellows above have mentioned. Explosive force fire. It will instantly melt steel. Fuses sand to glass. One of the profs in college was cleaning tundishes that contained pure sodium dust (another alkali metal). Asbentmindedly used water. The resulting explosion blew out over 200 windows. Halibrand, and nowadays, Volk, wheels use mag alloyed with aluminum. Very light and strong. Even when alloyed, mag is dangerous. I've a friend that was grinding on an old VW case, and a spark caught the dust on fire. Burned him pretty bad. Another friend was machining it at work and burnt down a mill. Until a few years ago, beryllium was used extensively in Formula 1, alloyed with all kinds of other stuff. All throughout the engines, brake parts, etc. It was horribly expensive to make, and machine. The machining centers had to be sealed and the machinists wear respirators, because the resulting dust is deadly. The sanctioning body banned it because the teams at the back of the grid could not afford the material engineering and manufacturing facilities that the top teams could. All of that said, piston development nowadays is moving towards ceramics alloyed with aluminum. You have the excellent thermal characteristics of ceramic (low expansion, high heat capacity (like a fire brick)), combined with the light weight and strength of Al. The problem has been that the combo is brittle, but I think this is being overcome with newer alloys. Al use for valves seems improbable. High performance applications such as Pro Stock and NASCAR use titanium, Inconel, and other 'superalloys' that come out of the aircraft industry. The stuff that they make jet turbines out of. Exhaust valves get hotter than pistons, and with ever-increasing emmissions requirements, the combustion charge temps are going up, to burn off particulates. Materials and technology from the high performance applications typically filters down to OE usage as they become more cost-effective.
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