mayhem

iTrader: (9)

Was the 300zx (VG30DETT) Al?

ian840

The biggest difference between the new cobra's 5.4L and the ford GT's 5.4L is the cobra uses a iron block and the GT uses a aluminum block. im pretty sure the GT is running higher boost and it seems to work ok, putting out close to 600hp. so maybe there is hope?

Vishnu_Evo8

iTrader: (6)

my god the new cobra is a5.4 iron block.. this thing is gonna be retarded.

C6C6CH3vo

iTrader: (9)

5.4 L cobra? They have to increase displacement by 800mL just to keep up with the acceleration of the 2 liter competition. JK

If the X is going to involve that much of a change to the Evo then the IX may quite possibly be the last of the Evo as we know them and I wonder if it would be the last of positive mutating as well. I saw a picture of a X concept and it looks like a cobalt.

On the other hand, considering the price of beans in China, the cast 06 IX block has been reported to have changes in the construction to retard detonation.

Trojan man

iTrader: (10)

Whether or not the Al block holds up to higher boost is going to be more contingent on the block's design than the material itself.

Al has proven itself more than capable of sustaining 1000+ hp on ls1's (which is not a motor designed with boost in mind, at all!) In fact, I don't know of any ls1's that have had block failure due to high psi levels.

On the other hand ford has chosen to run iron blocks instead of al in their FI mustangs and
Al in the GT. So it seems that al may require some more careful engineering, but will still be just fine with the boost.

Also, it's greater heat dissipation should only help to reduce knock occurrences. Al blocks are not an untested territory for performance cars, and I'm looking forward to knocking possibly 30lbs - 40lbs off the nose of these beasts

Elite Evolution

I think the GREATEST benefit the IRON block has over an AL one is that the HEAD is anchored into a more stbale metal and has less of a chance to lift off.

ShaunSG

iTrader: (1)

When comparing block strength and longevity look at cylinder pressures roughly indicated by BMEP (ballooning and sideloading) and engine speed (sideloading and inertial loading) averages in typical, not one off, mode of operation. Both factors relate to specific output (heat concentration). Smaller factors involved are cylinder number, bore-stroke ratio, fluid manifolding.

Aluminium blocks are almost always made to be lightweight and handle low specific outputs. In a front engined car designed for true road course performance the halving or near halving of block mass - mass that hangs over the nose of the car especially, is worth saving. In endurance engines operating range BMEP and engine speed are low so there is further motivation to go light. Power loss at these levels is not large. Handling is everything.

Alu blocks can be made as strong as cast iron blocks but they end up being very big because of required thicknesses.

Standard liners in alu blocks don't do anything for strength. They are there to provide a wear surface. Liners that convert a block from open to semi-closed deck help somewhat with bore stability but are no substitute for proper design from the start.

The problem with aluminium blocks, especially open deck ones, is that the bores don't maintain cylindricity well under thermal and mechanical loads. When they don't stay straight, round, and centered, you lose power from blowby and increased friction. A lot of work is needed to make sure that a highly stressed aluminium block's cylinders stay true and still it doesn't last anything like cast iron blocks twice the weight. Again this is only a concern in highly stressed applications. Highly stressed meaning ~15 bar BMEP ~150hp/litre V8 turning over 9500 RPM at mean piston speeds exceeding 29m/s and well over 6,000 G inertial loads. Here an aluminium block saving you 100lbs may lose you 50-80 hp by sheer inefficiency and get worse a lot quicker than the cast iron anvil.

SaabTuner

Not only that, but strength density becomes an issue since the modulus of elasticity and shear modulus for aluminum is about half that of a good cast gray iron. (GM-60) Iron is also extremely in-compressible. You could put more reinforcing aluminum around the cyllinder sleeve, but then you'd loose cooling efficiency and might distort the sleeve.

There are "better" materials than iron for blocks, but none have anywhere near the cheapness of iron. Can't beat cheap AND effective.

ShaunSG

iTrader: (1)

There's where hot honing comes in and is the reason why you can't even turn an F1 engine over at room temperature with bores that are out of round and twisted .004-.007". Such is the degree of block flimsiness, yet it is a case that will hold over 900hp for hours at over 18,000 RPM, and one that you pick up with one hand.

SaabTuner

Yep, I was looking up stuff about that the other day. There's a company called Perfect Bore that does hot-honing. They also make Metal Matrix Composite pistons which Ferrari either currently use, or used fairly recently, in their F1 engines. Interestingly, the FIA banned the MMC used by the Mercedes McLaren team, an Aluminum/Beryllium composite alloy.

Although, instead of outlawing the alloy itself, they outlawed any material with a specific modulus of elasticity over 40 GPa/(g/cc). AlBe has a specific Young's Modulus of about 90 GPa/(g/cc) and pure Beryllium around 165 GPa/(g/cc). Even the best wrought grades of Aluminum are only around 30.

x838nwy

Wouldn't it be nice if Mitsubishi puts that in the evoX. As great as this material is, I don't think the FIA would allow it in the WRC so its chances of finding its way to the x are very slim. That's something I really don't get with the FIA, I mean materials like this are clearly superior and a major reason that they're so expensive is that while there's loads of potential, there's no actual useage!!

Just imagine the advancment in technology and performance if these exotic materials are used in mass produced engines. In stead we get F1 teams spending millions on aero designs which are frankly useless to the millions of drivers around the world.

Off the top of my head, the most relevant technologies from racing that we have are turbo chargers, ABS, tyres in general, disc brakes and brake materials and electronics engine management all of which are pretty old news. Somehow the FIA seems bent on making racing as useless to us as possible. Let's hope the new Concorde and the new WRC rules change things for the better.

Now that I got that off my chest, I'll stop now...

SaabTuner

I'd love to see the MMC's used in the Ferrari F1 engines used in the Evo. They're stronger than typical Aluminum by a significant margin.

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.

Still, for uber-high performance aftermarket pistons, it would be hard to match the strength, rigidity, high fatigue resistance, and extremely high thermal conductivity (more than twice that of aluminum) of pure Beryllium. Beryllium is also around 30% lighter despite being nearly twice as strong per unit volume and it melts at a MUCH higher temperature. (Closer to that of steel.) Crazy stuff. If it weren't so hazardous to mine and refine, it would probably be MUCH cheaper as the element isn't especially rare in its oxidized mineral form.

NASA is, or was, working on pure carbon pistons. They'd need to be anti-oxidant coated, but carbon is both lighter and dramatically stronger than aluminum when processed properly. I've also thought of infiltrating the upper portions of a carbon piston design with silicon to convert the upper regions to silicon carbide, which is extremely temperature-resistant despite still being a good thermal conductor.

Ceramic carbon composites might be the next generation of engine materials as their price has been dropping dramatically in recent years. {thumbsup}

ShaunSG

iTrader: (1)

Hot honing systems are available to anyone with 70K USD.

MMC is outlawed and has not been used for at least 6 years. These was some experimentation with them but not a whole lot of actual use.

SaabTuner

I only mentioned that specific company because of their previous association with F1.

They outlawed it for this new season for use in the engine with the V8 regs by use of less-ambiguous wording. It's still legal for use in other parts of the F1 car, as far as I can tell.

Until 2005, however, the regulations ambiguously stated this about MMC's in the engine:

http://www.fia.com/resources/documen...nical_Regs.pdf

The wording is rather loose. Silicon Carbide reinforced Metal Matrix Composites would still be arguably legal since, though they contain carbon, they are not strictly carbon fibers (IE graphite), nor are they aramid fibers (IE Kevlar). SiC is a ceramic. There are also a number of fairly strong SiC reinforced MMC's out there, such as this one which still meet the Young's Modulus rule of 40GPa/(g/cc) which would otherwise outlaw them along with the AlBe alloys.

To avoid that confusion, this year F1 changed the regs to read this:

So now they are outlawed. I cannot find any good source on MMC's in recent years which states anything other than that Ferrari was trying to get the AlBe alloys used by Merc/McL banned though the Youngs Modulus rule so that the Ferrari F1 team could still use MMC's (less than the YM rule)... and that was more than six years ago. I just assumed they went through with it since MMC's weren't explicitly banned. But I don't exactly have an inside source with Ferrari.

Anyway, back to our regularly scheduled programming.

ShaunSG

iTrader: (1)

The director of motorsport at the piston manufacturer that supplies almost 60% of the cream of the F1 grid including Ferrari, said this year, that MMC is not typical. Ferrari as far back as 2000 were running standard alloys.

Engineers from another good F1 engine supplier that is not a customer of aforementioned company, say the entire grid is running standard aluminium alloys and has been for a long time. Their company has run standard alloys as far back as '97 including an engine that was driven to a WDC.

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.