Is there any difference besides weight when it comes to these engine blocks.

I think I heard that the X will be an aluminum block, will it still be able to hold all the power that we give it??

 

I read that too. I really dont like it as the cast iron block on the 4g63 has proven itself for such a long time. Why fix it if it isnt broke. I think it will be fine for anyone who does light modding but if you are planning on doing a lot, might want to stick with the evo 9. Not to mention the automatic trans with paddle shifting. I personally would wait and let other people do the testing before buying one to mod.

 

heat dissipation/retention is also different from aluminum to iron, with aluminum cooling down quicker

 

Well, I think Mitsu know the advantages of the cast iron block over the aluminium one. But the Al does have attractive qualities such as its ability to conduct heat better and being slightly cheaper to manufacture.

I'm sure if they do go that route, it's not going to be for no reason, but I think we will loose the ability to run our evo's at insane boost levels due to the decreased stiffness of the Al. [unless they use some really exotic alloys]

Strangely enough, the new Mazda Miata went from a 1.8l cast iron block to a 2.0l Al block. It lost only 5.4kg.

 

since when does aluminum cost less than iron?

 

Umm...aluminum IS cheaper than iron -it is more readily available. Secondly, aluminum tends to react to heat much faster in expansion/shrinkage. This usually is the cause of hairline cracks in the block..you have to remember, there is coolant flowing around the walls of the piston chamber. High heat dissapating from the friction off the piston walls on the insides of the chamber and cool coolant flowing outside of the chamber. I don't think they'll resort to using aluminum blocks and if they do in my opinion the motor wont be able to withstand an FI application with high hp for too long esp. being a DD.

 

I really dont know about Aluminum being cheaper than Iron but what do I know. I do know that all aluminum blocks use iron sleaves so block integrity at high hp levels shouldnt be an issue.

 

Aluminum Alloy is not even close to being as inexpensive as Iron...whoever even remotly thinks that is a baffling idiot. It can be cheaper to manufacture because its easier to work with, but no car company has elected to use Aluminum as a cost reduction technique.

 

Aluminum can be repaired if damaged. It's not always weaker either.....look at the 4.6 Cobras that are running well over 1200hp with aluminum blocks.

 

When you look at things like engine blocks, the majority of the cost comes from the machining operations rather than the material costs. If you look at it in the cast form the material cost is probably only 15% of the costs, in this case.

All in all, both materials should cost roughly the same to cast but this depends very much on the method chosen. But once you mass produce the part, the casting cost should not be a major issue.

The largest chunk of the cost is in machining and Al is much cheaper to machine. Another plus is the thermal conductivity of al means that you can have the cooling channels not so close to the surfaces which allows for shallower hole depths and larger tolerances all round. So machining cost will be reduced.

Going back to materials, if you look at how much al alloy coast per kg and how much an hour cost on a 3/4/5-axis CNC machining centre with gun drills, you'll get the picture.

Now I'm not saying that the cost saving will be the only reason why mitsu would switch, but it is one of the plus points. The reduction in engine block costs is probably not significant when you look at the selling price of the evo.

I do not know if car companies use al blocks as a cost reduction technique, and frankly I don't think I ever will since I do not sit in on their engineering meetings but I doubt they'd say in the brochure "we use al for the engine block to make it cheaper for us". As I mentioned, it is a plus point (if you don't include the cost of re-tooling) but not a major one.

 

The 03/04 cobras use an iron block, chief. Only the n/a cobras were running aluminum blocks.

Ive heard from several sources that Ford wanted to use an aluminum block on the upcomming 5.4L supercharged Shelby, but testing at production boost levels resulted in "catastrophic failures".

 

Umm, notice I didn't specify 03/04 Cobras . The '96-'98 Cobras used aluminum and they are STRONG. Mihovitz is making 1500+hp with his block.

Another example is y2khawk(Harlan) who post on LS1tech, he traps 171mph @ 3350lbs and uses a stock LS1 block

 

don't the new corvettes have aluminum blocks?

 

yes

 

is it true though that once you overheat it, you're f****? it gets all warped and stuff? not to the extreme but minor warping?