Advanced Engineering Tech - magnesium block

i just want to know what you guys think about having a magnesium engine block ?

supposed to be lighter then a aluminum block, and i think allot of production cars will start poping up with magnesium blocks to cave weight/have better fuel economy.

some racing cars have magnesium blocks but from what i have been told is that magnesium does not like high temp's too much.

it doesnt sound very safe. magnesium is very flammable you know. its used in fireworks i believe

so you are saying that racing motors are made out of fireworks ?

it is probably not all magnesium, it is a magnesium alloy, just like the aluminum block are not all aluminum, it is an alloy. meaning a mixture of some other stuff in there

i think BMW are currently using Mag Ally blocks on the 3.0ltr 6 cylinder engines.

It is MUCH lighter than ally! however you have to keep it painted or it corrodes.

i think there are other areas to look into first before going down this route. Chassis design and material choices in the chassis can make a massive difference to weight. the easiest way to reduce weight is take all the creature cumforts out the car! thats what lotus have done in the Elise and what the Caterham/Lotus7 guys have done for years!

Also making cars smaller helps alot! you use less material that way ;)

Chris.

Some aftermarket company made Magnesium BBC blocks back in the 70's. Just wondering why this material did ot catch on? Price??

Certainly not a commodity feedstock like aluminum is,
and for a marginal weight improvement you have to
re-engineer it all for the different ductility, expansion,
and so on. Plus the aluminum's native oxide which
protects the base material (heads) from being consumed,
is not matched by chalky magnesium oxide.

If you're trying to save 10 pounds on an engine block,
hell, go beryllium. So what if its dust is big time toxic
and it's similarly chemically reactive. If it only has to
last 7 seconds, and you get it free for putting a
sponsor sticker on the vehicle, who cares?

On the other hand, your Joe Neglect consumer is
going to trash anything exotic resulting in major
giveback problems. Hell, people are too cheap to
put anything in the radiator that doesn't come out
the garden hose, from the look of some motors
I've seen. So don't expect this stuff to hit the
low end of the mass market anytime soon.

My experience with Magnesium blocks stems from a v12 engine we worked on at CJ Batten's back in the 90's. The block moved HORRIBLY when you measured at room temperature then at 200 degrees of water temperature. Round holes (cylinders and mains) weren't even close to round any more. Not good for blowby, cylinder sleeve retension, or bearing life.

Caddywack made some Mag intakes on their Northstars but stopped. Probably due to the thermal expansion and price issues mentioned earlier.

I have one. It has been sitting in a garage and never used. It is very corroded.

Considering that mag is used as a sacrificial anode I would say that your engine will be more scared of corroding away then from wearing out the bearings or strain from its own operation.

well i didnt claim to know anything about using magnesium for engine parts, just thought id offer my 2 cents

im pretty sure that a bunch of volkswagons were made with magnesium blocks, and they had some issues with engine fires. well at least my friends at the fire dept have issues with the vw engine fires, because water cant put out magnesium fires...

Intresting...

I am a BMW mechanic and at school we saw a demo of a guy trying to light a mag block on fire and he could not do it. It would have to be ground into dust or shavings to easily ignite is my understanding. I have also seen a V12 with mag intake manifolds that caught on fire and the intakes were only smoke damaged so I think it is more stable than people give it credit for.

The main problem with magnesium is it is highly corrosive. All the BMW mag blocks use only aluminum bolts on the engine (except head bolts) and you must keep the threads free of any oil or coolant.

it doesnt sound very safe. magnesium is very flammable you know. its used in fireworks i believe
So is aluminum. So is iron.

I am a BMW mechanic and at school we saw a demo of a guy trying to light a mag block on fire and he could not do it. It would have to be ground into dust or shavings to easily ignite is my understanding. I have also seen a V12 with mag intake manifolds that caught on fire and the intakes were only smoke damaged so I think it is more stable than people give it credit for.

The main problem with magnesium is it is highly corrosive. All the BMW mag blocks use only aluminum bolts on the engine (except head bolts) and you must keep the threads free of any oil or coolant.

the bmw motor you are talking about used iron sleeves or some sort of lining for the cylinder bore ? it would be pretty shitty if they used a liner.

Its has very poor corrosive resistance, it is also "brittle" I am sure the forming process is alot more difficult. I saw pictures of some brand new aircraft parts that got salt water on them from an emergency water landing. WOW, it was crazy how quickly they corroded to being worthless.

ok, aperantly the magnesium alloy that was designed to be used for engine blocks is called AM-SC1 and should withstand 150-200°C. but can't really find any info on how this alloy is against corrosion.

I personly like cast iron blocks.

Has anyone ever heard of an engine block built from titanium? It seams like if you were looking for weight reduction and strength (and you had plenty of bucks), it might be better.

Just kind of FYI, Aircraft rims are largely made of magnesium and those things go trough some hell of abuse. Next time you touch down on a runway just remember, your tires are flammable, lol.

i have never seen a race motor made out of titanium, but plenty with a magnesium alloy.

i also think aluminum is less dense then titanium so titanium should weigh more.

Titanium doesnt really get rid of heat like aluminum does if i recall correctly. The big bonus to titanium is its lighter than steel and maintains its strength at higher temperatures. But doesn't the cylinder sleeves take the brunt of the combustion anyway? So then why do titanium at all?

I do not know which is heavier, but I know titanium is stronger and very light. The SR71 Black bird is made from it. I know titanium rods are lighter, but that is probably because they are stronger and need less material to do the job. Don't they make valves out of it too? It is very expensive though, and for the weight reduction you would have in a block it is probably not worth the money. It would be cool to say I have a titanum block. As for magnesium, I had an intake for my old Honda motorcycle that was made out of it and it cracked. i had no idea it was magnesium until I had it welded up. The shop did not realize it was magnisum. It caught fire, and burned at a very high rate. It was blinding how bright the burn was. It finaly burnt out and wow what a mess! I think the real problem was mentioned before is the fact it is a lessor metal, so it will eat away due to electolises in the cooling system. It is used off shore to protect the platforms and ships from corrosion, and it is sometimes placed in large industial engine to protect the liners from corrosion due to electolises. Aluminam does the same thing, it is a lessor metal as compared to cast iron, hince the reason for the different colored coolant with special inhibitors in it to protect the aluminum componets. I do not know what the inhibiters are but I bet magnesum is in there.

ok, aperantly the magnesium alloy that was designed to be used for engine blocks is called AM-SC1 and should withstand 150-200°C. but can't really find any info on how this alloy is against corrosion.

That is why it is really awesome if you are a transcontinental flight, overloaded, mind you.

And you have to emer land right after take off without being able to dump fuel. :chug:

Wish you had those Brembos now huh???

yea the sr71 used to leak fuel when it was on the ground, because the metal expanded when it was in the air. i think the whole plain was a foot longer in the air then on the ground. but it was probably not made of the same am-sc1 alloy.

This is off topic but I have touched a SR71 once. They have one on the parade ground at the Air Force Boot Camp in San Antonio TX. The cock pit was painted over and the engines were removed but it was there. Bad arse plane. And how would you like to be the poor guy who had to crawl outside and messure that thing at mac million?:bang:
:hijack:Sorry I just had to get some comedy in.

As for magnesium, they built 12 concrete ships during WW1 that actually floated, so why not make an engine block out of Magnesium?

This is off topic but I have touched a SR71 once. They have one on the parade ground at the Air Force Boot Camp in San Antonio TX. The cock pit was painted over and the engines were removed but it was there. Bad arse plane. And how would you like to be the poor guy who had to crawl outside and messure that thing at mac million?:bang:
:hijack:Sorry I just had to get some comedy in.

i watched a documentary about it and that is what they said. i have no idea of how the measured it. it sort of makes sense, otherwise the fuel would not be dripping out of it when it is on the ground. anyway can we get back to magnesium please

also i forgot to mention that Nissan's vh45de motor was recast in magnesium for racing in group c in japan. they called the motor VRH35Z , it also had smaller displacement at 3.5 liters. but after sometime they made the same motor out of aluminum alloy called the VRH35L. wonder why ?

here are some figures

The VRH35Z produces 800 ps @7600 rpm and weighs 408 lb (185 kg).

The VRH35L produces 650 ps @6800 rpm and weighs 375 lb (170 kg).

how did the manage to make the magnesium block heavier then aluminum alloy i honestly don't know, but that is probably why the decided to stick with aluminum alloy, then magnesium alloy for their racing motors

Have we covered that Mag might require more tooling cost through increased machining time and wear on the tool heads?

Does it require more expensive casting techniques or more limited in how you can cast it?

The turbine engines my father and I rebuild are made out of magnesium, we'll at least the gearbox is.

http://upload.wikimedia.org/wikipedia/commons/thumb/6/69/Turboprop_cutaway.jpg/800px-Turboprop_cutaway.jpg

This is off topic but I have touched a SR71 once. They have one on the parade ground at the Air Force Boot Camp in San Antonio TX. The cock pit was painted over and the engines were removed but it was there. Bad arse plane. And how would you like to be the poor guy who had to crawl outside and measure that thing at mac million?:bang:
:hijack:Sorry I just had to get some comedy in.

I saw the last SR-71 takeoff, it was at Beale AFB near Yuba City. That thing was badass! It was March 6, 1990. I'll never forget that, my dad came and took me out of school to watch that thing fly. I was in first grade. :D
I also had dinner with Brian Shul who was one of the SR-71 pilots, really a nice guy. You should have heard some of his stories. Unbelievable shit went down with those SR-71s!

I would love to hear some of those stories! I thought they gave a couple to NASA and maybe another scientific resurch center for High altitude research. I also thought I read somewere that they put one or two temperarly back in service for one of the Iraqi conflicts due to the fact the Iraqis knew when the satalites would pass over. Maybe it was the U-2 that was being used at the time. Either way that would be very impresive to see one flying.

As far as magnisium, dont they use it on the shuttle? Saw the one go up yesterday, I have to see one go up in person some day, talk about realy power and big wevos to ride one!!!!

im pretty sure that a bunch of volkswagons were made with magnesium blocks, and they had some issues with engine fires. well at least my friends at the fire dept have issues with the vw engine fires, because water cant put out magnesium fires...


Yep, all the air-cooled VW's had AS21 or AS41 mag alloy blocks. In a prior life, those little jewels were all I messed with. Usually, the engine fires were caused by the brass fuel line fitting in either the carb or the fuel pump coming out and spraying gas everywhere. Out of the hundreds of those I personally worked on, I never saw a block that had ignited. Most could be salvaged by replacing all the melted aluminum and pot metal parts. The long block would be fine. The shavings from various VW block machining operations in the floor around my mill, that is another story. I learned the hard way that they can and will ignite easily.

The aircraft I work on have magnesium main transmissions and they regularly get replaced due to severe internal corrosion. They are painted but any chip in the paint means it has very little service life left. I can't see this being efficient for consumer vehicles. It is used because aluminum could not handle the stresses placed on it, but most other metals are too heavy.

Only the outside case of the BMW engines are magnesium. It doesn't touch oil or coolant, I believe. The head gasket has an external flange so that fluid cannot touch the aluminum head and magnesium block at the same time, otherwise it would lead to a good amount of corrosion. Magnesium's expansion rate is almost identical to aluminum's, btw.

can you get us a picture of the block if you don't mind ?

Just kind of FYI, Aircraft rims are largely made of magnesium and those things go trough some hell of abuse. Next time you touch down on a runway just remember, your tires are flammable, lol.
They don't come into contact with any flames. Unless you had a brake light up, still it won't set it on fire.

I wonder if we could make ceramic blocks? Or maybe not. Rolls Royce went that route and it cost them so much in R&D that they ended up having to sell the automotive division.

wow that was an educational read... preciate it fellas.... ( no sarcasm intended)

My experience with Magnesium blocks stems from a v12 engine we worked on at CJ Batten's back in the 90's. The block moved HORRIBLY when you measured at room temperature then at 200 degrees of water temperature. Round holes (cylinders and mains) weren't even close to round any more. Not good for blowby, cylinder sleeve retension, or bearing life.

That wouldn't be a Bugatti V12, would it? The Bugatti EB110 had a 3.5 litre quad turbo 60 valve v12 that produced over 550 HP. It has a magnesium block with aluminum heads.

I don't know the specifics of the BMW blocks, but consider the relationship of iron and aluminum in the LS1. That's the same relationship shared by aluminum and magnesium in the BMW. Aluminum is used for the high load/high wear points, while magnesium is used to make sure you can't see through it.

However, BMW only uses the magnesium blocks in the N/A engines. The turbo engines have fully aluminum blocks for strength.

In mass production, magnesium is actually a very cheap material, partly because it's actually very easy to work with, thanks to a low melting point. I think the C6 engine/suspension cradle is cast magnesium. While magnesium itself isn't as strong as aluminum, it's enough lighter that you can add material to get the strength back and the final part can still save weight vs aluminum. Since it's not that expensive in bulk, the choice is easy.

Titanium is lighter than iron, heavier than aluminum, but as strong as the highest strength steels. The wing box (where the wing spars tie into the fuselage) on the F-22 is cast titanium.

There was a buy a while back for magnesium Cadillac 500 intake manifolds. The producer already had a low volume of sales for aluminum manifolds. He put out feelers to gauge interest in magnesium, which wasn't very high. The cost increase was only about $50 (mostly due to magnesium being an oddball for that foundry), but the weight savings was a few pounds.

old school VW's were mag cases. Since they are all air cooled, I don't think that heat is that much of an issue since they are air cooled. I drove VW's pretty much in my younger years, drag racing them and even had a 10 second bug.

If it lights up better have your welding helmet on! :]

I am personally still holding out for a block made of complete Unobtainium. I hear the new Street Warrior intakes are made of that stuff....

http://www.magnesium.com/w3/forum/read.php?thread=4292
http://en.wikipedia.org/wiki/Magnesium
http://www.azom.com/details.asp?ArticleID=355
http://www.sae.org/automag/techbriefs_06-00/05.htm
http://www.magnesium-elektron.com/about-magnesium.asp?ID=4


the flammability, or igniteability, of magnesium is often blown out of proportion or taken out of context. Magnesium, as in pure magnesium, is highly flammable and easily ignited when it is in powdered form, and less when in shavings. It corresponds to how much surface area of the metal is exposed to an oxider which is generally the oxygen in air. Magnesium will also burn without oxygen, it can burn in pure nitrogen gas or in carbon dioxide. and you can look most of this up on wikipedia or google,
the other thing is how much mass of magnesium there is, greater mass requires greater heat before it will burn, i suppose you could compare it to building a fire with wood- start off with small light twigs no problem but try to get a 1 foot diameter log going all by itself and it takes a lot of heat to it before it gets going on it's own.
And magnesium also has decent thermal conductivity, and in a chunk form it has to melt technically before it ignites and burns. by the time that happens with an engine block, the rest of the car is already burnt so what does it matter.
the other reason why i say out of context is people just hear magnesium and think the whole thing is 100% magnesium, it is not. It is an alloy, and i don't know off the top of my head what magnesium alloys are, probably 30-70% of Mg with aluminum as the other main component, just like for titanium. So that further reduces the flammability aspect. What you really have to watch out for are those small magnesium alloy parts used in car interiors, those are what burn in car fires that cause problems which can be unexpected. And to put it in another context, how many rims out there in racing or on street cars are magnesium? Ever hear about those flaring and burning in car fires? I really haven't.

As for engine blocks, i doubt Mg alloy block will ever be used in production because the weight savings does not justify the cost of the design and durability. Mg is at the bottom of the galvanic chart, which means it corrodes very easily. Alloying helps with that but coatings are generally required which increases cost. The biggest thing that comes to mind is the cylinder liner in contact with the Mg alloy block with coolant and heat- a perfect setup for galvanic corrosion! Engine coolant would have to be designed to handle that if even possible, plus with cast iron cylinder liners iron is much higher up on the galvanic chart furthering the galvanic problem, you could use an aluminum alloy liner but then you lose durability, and strength which would limit power output. Then there's the interface between the materials of the cylinder head and head gasket. All to save maybe 50 lbs over an aluminum block when in vehicles today that are all over 3000 lbs doesn't make sense. In a race environment where cost doesn't necessarily matter then maybe.

As for engine blocks, i doubt Mg alloy block will ever be used in production because the weight savings does not justify the cost of the design and durability.

http://www.bmwusa.com/Standard/Content/Vehicles/2010/3/328iSedan/ModelHighlights/328iSedanPerformance.aspx?enc=Phf9vo0zeKPjevOeb4QF sQ==

"Our inline six engine offers smooth power, greater acceleration and 200 lb-ft of torque at at 2750 rpms. A number of pioneering technologies make it possible. An electronically controlled water pump helps increase power output. Our patented Valvetronic system offers better fuel efficiency. And to save weight, we used a groundbreaking innovation that BMW was the first to use in a production car - an engine block made of a lightweight composite magnesium/aluminum."

BMW has been using it in production in its best selling car since '06.

i know bmw has had a Mg block,
let me rephrase and say i doubt a Mg block will be used by all manufacturers for all engines made anytime in the near future.

check out link below for the tech stuff on the bmw mg block,
it describes how the Mg alloy components are only comprising the shell of the block, the coolant jackets and inner block where the cylinder liners are cast aluminum,
and if i read it right weight savings is only 22 lbs over the previous non-magnesium block.
BMW has never made an inexpensive car, which is fine, but i seriously doubt other manufacturers are going to follow suit and invest into the design and production of a Mg alloy block "shell" to save what i'd say is minimal weight. and the BMW Mg-block is an inline-6, weight savings would be less on an inline-4 further increasing the cost-to-weight saved ratio, and on V-6 and V-8 engines it may not even be practical or feasible to design a Mg alloy shell for the block.

http://www.mwerks.com/artman/publish/features/printer_960.shtml