lets also not forget about what Mitsu did to the eclpise, It evolved into a very weak car.

 

it is just me, or can people not spell Hyundai right...

 

Kinda nice having those dummy proof colored markings on the timing chain. sure would be a time saver on the 4g63s belt. But anyway, like I said before...You can always trade in your IX for a new X if you like it better, but you'll never be able to get a new IX again. (or at least very soon you wont)

 

Don't want to sound like a smart-*** but 4G63 was actually released in 1984 in Dodge Colt. It just shows how old the 4G63 really is. I am more than sure that Mitsubishi over the quarter of a century was able to learn a thing or two about performance engines and the next generation will be even better than the previous in every imaginable aspect.

Also, all this talk about raw power and such, I understand a lot of people here like to drag race, but Evo is a rally car, handling is probably the most important aspect for this type of cars. I've never driven in an 800HP Evo but somehow I have a feeling that even an Evo frame reaches a HP point where all the additional power is basically uncontrollable (useless) on a not straight track (non-drag race) and thats what Evo is not about. Evo is a perfect balance between performance and handling (road holding).

Eclipse was/is a different breed of car, first off, the displacement was never limited to 2.0l due to WRC rules, second of all Eclipse never was a global car, it was made solely for American market, third of all, actually when you compare 0-60 times from generation to generation of the top models, from year to year it got better so from performance point of view Eclipse never actually suffered. Of course the AWD/turbo was taken away from the 3G/4G but then again the displacement was increased so there wasn't a whole lot of performance loss anywhere. The only thing that the 3G/4G Eclipse lacks is the AWD system but then again Mitsubishi didn't sell a whole lot of 2G Eclipses with AWD/Turbo as they were expensive and simply there wasn't enough intrest in them compared to it's NA/non-AWD models.

One thing though is the continuous adding of weight from generation to generation but that is a problem of every car manufacturer and more strict governemnt safety regulations. What I see happening is that car manufacturers (even on the low-end) will start basing their cars on all-aluminum frames as thats how the high-end cars are starting to be made this days (aluminum engines also were first introduced on high-end cars and as materials and technology got cheaper it made it's way to mainstream and even economy cars see benefit from it). Cars in the 1970s also were heavy but then came a transition period and introduction of lighter/more durable materials and the average weight of cars by the early 1980s drastically went down. And I think we are at a point where cars are too heavy again and we will see similar trend with introduction of even more lighter materials, but thats the beauty of technology, it doesn't stand still, it always evolves into something better.

 

oops

 

I don't think the open deck honda problems are going to show up as much in the 4b11t. It looks like the cylinders are supported farther up than on a honda, which should help the strength out. The reason they went open deck is because it is much easier and cheaper to make an open deck engine, it cuts down on machining costs.

People have also been talking about hp/l and that aluminum blocks can't handle it. Crotch rocket engines are aluminum and NOT sleeved and they make almost 200 hp/l, rev over 15k and don't have problems.

 

i think this also! did a bit of reserch into WW2 fightes and came up with some intresting stuff!

google power recovery systems/turbines. also have a look at the later stages of the saber naper engine (when they switched from the flat 24 to the flat 12). they used a turbine to drive the supercharger, but it was also geard back the the crank!

alos have a look for the 6 stroke engine. this injected water on the 5th/6th stroke to recover some of the heat in the engine.

thanks Chris.

 

one reason the LS guys cant make more power is dept. this isn't helped by the massive cylinders they are running. on a small displacment unit you can run much more boost than the bigger stuff before for start to see dept become a problem.

also i was trying to show the worries people have about ally and how that with a little practice its normally a load of cr*p! like is said the domestic guys thought ally blocks could only take 600bhp. now you cna buy creat engines that are designed to run upto around 1250bhp. thats with an ally block and heads!

im not having a go at the new Evo motor, quite the opposite! im saying ally tech has come on to the point where the use of iron really isn't needed unless you are really after ball to the wall power! take a look at what the german guys are doing with ally blocks and a couple of turbos.

also what makes you think the 2.0 ltr motor wont go over 350bhp if made out of ally???? ford and scooby use ally blocks for their WRC motors and they are running massive boost, comp., torque, etc, etc.

i know none of us really like change, and the saying if it aint broke...... but come on guys i think Mitsubishi should know what they are doing by now dont you???????????????

Chris.

 

^+1

 

I don't think this is true. While the sleeves do indeed increase the power capability of the block, you still have to realize that the crankshaft is still encapsulated in very soft aluminum (main caps). High power aluminum engines begin to twist and flex longitudinally regardless of sleeving. This is why cast iron is better for high power applications. Just look at the modular V8 mustangs, to make big power they all look to the cast iron 5.0 or terminator engines, and the regular aluminum modular 4.6's are all sleeved (and still weak as hell). The 4B11 will not be able to touch the theoretical power capability of the 4G63. I predict that while currently, there are 1200-1400 hp 4G63's lurking about at dragstrips all over the world, the 4B11 won't see any power levels above 500-600 hp. Metal is metal. While a clever structural design may increase the overall strength a bit, you can't change the physical properties of cast aluminum (unless you cryo it maybe). Just look at the history of all aluminum engines versus their cast iron counter-parts, its not like Mitsu will come out with some magical design that will increase its power capability/displacement ratio far beyond anyone else's design. When it comes to the theoretical maximum power output of an engine, think of the engine as metal box. If you drop a couple of firecrackers into a tin foil box versus one made of sheet metal, which one will blow up first? People are just going to have to accept that the 4B11 will be weaker. It however WILL be a lot lighter...I suspect Mitsu sacrificed strength for agility. The Evo X needed to lose some weight somewhere considering how much heavier the new chassis/drivetrain is.

 

^I think you are exaggerating the "flexyness" of aluminum a bit.

Basically, it will come down the Modulus of Elasticity of the material. This modulus relates the imparted stress to the strain that occurs. Strain is a measure of deformation. For example a strain of 1.05 means that the stressing load stretched the material by 5% of its original length.

Stress (Force/Area) = E (Modulus of Elasticity) * Strain (Strained Length/Original length)

Anyways, from a quick search: cast iron is around 100-120 GPa while aluminum is around 70 GPa. These can vary greatly, since you can anneal aluminum to gain greater strength or use different alloys. There also seems to a lot of variation in cast iron as well. These numbers seem be to where the average is around, so I'll use these.

So basically when comparing Al and Fe, for an Al component to get the same deformation as Fe, you need about an extra 40-70% more cross sectional area to disperse the load. This is no big feat, because that only equates to increasing the linear dimensions of the object by no more than 18-30%. This is because area is squared. Example: Increasing the linear dimension like the diameter of a rod by 18% will result in 40% more cross sectional area.

1.18^2 = 1.40 or 1.3^2 = 1.70 (approx)

However the density of aluminum is around 2.6 [g/cm^3], while iron is around 7.6 [g/cm^3]; So it's easy to see the savings in weight can come from. But it's likely that the increase in dimensions for increased resistance to deformation will apply in all three directions, resulting in a volumetric increase in material by around 65-120%.

1.18^3 = 1.65 or 1.3^3 = 2.20 (approx)

so 2.6 [g/cm^3] * 2.2 = 5.72 as compared to the 7.6 [g/cm^3]

So this will result in weight savings of at least 25% over a cast iron piece, while keeping similar tolerances.

As far as yield strength goes, they are about the same it seems between Fe and Al, so designing a structure based the modulus of elasticity to get similar tolerances under similar loads is more viable than designing for mechanical failure points. Since there is more material in an Al block (up to 70% in the cross-sectional area), it will more than compensate for any extra strength that iron might have offered (it didn't seem like much from my search). Aluminum is about 400 MPa in tension, so:

400 MPa * 1.70 = 680 MPa

680 MPa is about what high strength steel yields at! So basically if one designs an Al block to offer the same elastic deformation as an Fe block, you will get a net yield strength about the same if it were made of high strength steel.

Basically, you can design an Al block to handle similar loads as an Fe block can, while saving weight, but increasing the occupied volume. All the numbers I obtained were from 2 or 3 redundant searches to zero in on an agreed number. The simple calculations done were to demonstrate the advantage of increasing the material used in a similar Al component as compared to a Fe component.

I can't explain why some other applications of aluminum blocks weren't up to the task of modding, but I don't think it's impossible to design a capable Al block.

It might have had to do with the casting process itself. Maybe the 4G63 was over built by accident and not on purpose. Since iron uses less material volumetrically, you will tend to have thinner walled sections. While this may be fine on paper, when you cast something and it when solidifies, it contracts. These contractions can significantly alter the final shape and they become more apparent in areas with less material. So material might have been added to it to compensate. The result was a bad-*** engine that could handle more stress than intended. Seriously, why would anyone design a 2.0 L block that could handle 900+ hp 25 years ago? But when Al comes along, there is more material and casting might have been more accurate, so the final product might be closer to its intended specifications. This may have given the impression that Al was weaker. I have no idea on this BTW, but I'm just offering a possible explanation on why Al may have a gotten a bad rep.

 

What about Honda drag cars?

Turbo B18C's making 800-1000whp with no problems.

Stock block K20's have made over 500whp.

Turbo 350Z's are making good power too.

Aluminum isn't the end of the world.

I'm sure the motor, while maybe not being able to handle quite the power of the 4G63, will still be capable of making more than enough power for just about everyone.

 

Don't pay attention to sonicnofadz. He rarely knows what he's talking about. He also has this weird irrational hatred towards the Evo X.

 

Cost. Additional material to meet the same strengths means higher cost. And Al is a bit more costly than Fe. So the failed examples probabaly weren't designed with the full amount of material needed to equal a Fe block (which was probabaly overdesigned in the first place.

Does this mean Mitsu will do the same? No.

What this means is that it's up to how the engineers design the block. Translation: Wait and see.

 

Exactly. If engineers wanted a design that could meet or exceed what the 4G63 was legendary for, they could do it with an aluminum block. There are costs involved with such a design and it will come down to the economics whether they will actually do it or not. A company has to turn a profit so, sadly, it will come down to the bottom line. Fortunately, Mitsubishi hasn't built a reputation on unthrilling economy or mundane reliabilty, but moddable raw performance. They thrive on that reputation and they won't forsake it for the same values that Toyota and Honda were founded upon.

In we trust.