mrarm
Well-Known Member
I'm going to buy a boring machine to make holesCan’t clearly see if the fender vent is functional or not but the other vents are all fake.
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I'm going to buy a boring machine to make holesCan’t clearly see if the fender vent is functional or not but the other vents are all fake.
Make Swiss cheese out of it..I'm going to buy a boring machine to make holes
Not trying to be rude, but thanks for the history lesson on Aluminum vs Cast Iron materials and how they are utilized in engines....as if I wasn't aware of the various technologies and materials used in today's auto applications.The N54/55 uses cast iron cylinder sleeve, but B58 is different: it uses one latest technology called “Electric Arc Wire Spraying”. This is a type of the ferrum plasma spray method, which creates a thin layer (0.3 mm thick) of iron on the cylinder wall surface and thus eliminates the need for using the cylinder sleeves. The ultimate goal is to save weight. For your reference: plasma spray is an exotic technique previously (for example GT-R, LFA etc.), however nowadays its cost is lowered so significantly that even Ford uses it in the EcoBoost engine family.
There are three main advantages (that I can think of) for a only cast iron block over an aluminum one:
Dimensional Stability: Aluminum grows more during the heating process than does iron. Extra precautions must therefore be built into aluminum blocks so as counteract this condition and prevent issues.
No Cylinder Liners: If you ever want to rebuild an aluminum block where the cylinder liners are toast, they must be replaced. This is a large machining expense in comparison to having to just bore the cylinders in a cast iron block.
Cost: Cast iron has been used in industry for many years and is fairly easy to produce. Aluminum, on the other hand, costs a lot more to refine from bauxite ore. Just in materials alone, the cost is greater. Then look at the cost for the cylinder liners and special casting processes which must be employed to get the aluminum block correct and the cost goes even higher. There is some trade-off, however, in the heating process (doesn't take as much energy to melt aluminum v. cast iron), and aluminum is easier to machine (less wear on the machine tooling/fixtures v. cast iron).
Yes you are true. I’m not an engineer car engine but aircraft ^^.Not trying to be rude, but thanks for the history lesson on Aluminum vs Cast Iron materials and how they are utilized in engines....as if I wasn't aware of the various technologies and materials used in today's auto applications.
I am not talking about the pros and cons of aluminum and/or cast iron. I am fully aware of the pros and cons of each type of metal. I am specifically talking about the architecture of a specific platform. BMW's Achilles heel has always been and will continue to be their base architecture and how their inline blocks are formed from a cast. For example, Toyota/Lexus don't pour molten metal in their castings....they have a process of sucking it from the top. This removes air bubbles in the metal so the casting is near perfect in terms of rigidity and complete material. BMW, Mercedes, Audi, etc.. still use the pouring method into castings...even on their high-end models. Pouring molten metal into castings is cheaper and faster than sucking the molten metal from the bottom of the casting up. Nissan does something similar with the R35 GTR blocks by sucking the molten metal up into the casting, except they go one step further and plasma spray the liners. The reason other manufacturers don't care about this process, is because they are more concerned about volume than reliability. Most manufacturers build engines to a limited specification because they assume the buyers will not go past those parameters (HP, TQ, detonation range, etc...).
Have you ever wondered why the 2JZ has never suffered from cylinder egg-shaped warping, or blocks cracking, or main journal warping even with high clamping studs? It's because the base architecture of the block (regardless of it being a cast iron block) was designed very well. The Nissan RB engines (although known for making big power) suffered from blocks cracking for some time. It wasn't until the mid R33 and on models that Nissan revised the block casting process. Again, i am not trying to compare aluminum vs cast iron...i think it's pretty evident which material is stronger. However, how the material is formed, shaped, and used ultimately determines it's real world strength and reliability.
Here is a good example of Toyota/Lexus vs BMW casting:
Toyota/Lexus Process of Casting:
BMW Process of Casting:
Sure, the RB's have their quirks they are not perfect, just like the 2JZ....but they are not as severe as some of the quirks you will find in say BMW inline engines. I am pretty sure the "major" flaws of the RB's were resolved mid R33 production...they were brought to the attention of Nissan engineers by Nismo racing team (cracks in block, oil pump drive stripping, coolant weeping, etc...). I am fairly positive these were alleviated by the time the R34's hit production. I would rather replace a Nissan oil pump with an updated unit, than strip the block to machine egg-shaped cylinder bores. It's interesting, because Nissan and Toyota learn from their mistakes and never repeat them. I honestly can't say the same for BMW....just take a stroll through some of the M forums and read the owner feedback on the M3/M4's .OT:
not to to hate on Nissan but all RB blocks through the 34 are pretty mediocre unless you get an N1 block. The RRR blocks are better than the JZ blocks though and rightfully so as they are JGTC and Group A certified, rare, and cost a TON lol.
The other issue the RB block has, well the 26 anyways, is coolant weeping from the side of the block due to thin, porous casting near a water jacket under the intake manifold. I've had two friends with this issue and if you Google it, it's quite common in all GTRs. Nissan actually issued a recall over it after first sending out a TSB to use epoxy on the outside of the block (yeah.....) which unsurprisingly failed to correct the issue. Instead, Nissan decided to replace the block on these engines, and some folks wonder what prevents it from happening again.
Guys that drag race the mk4 often "downgrade" the rear calipers to fit smaller wheels for bigger tyres.I really like the way this car looks. The only things that would bug me are the rear Calipers and the seats which look like some of the earlier spy shots and those didn't look all that great from what I could see. Personally I feel like it could have been much worse. We will be getting a Supra and that's already a big thing. This car won't be everything to everyone but I honestly like where it's at from what we have seen (speculation aside). I feel like whatever major they change on the vehicle, will have an effect on something else. Like a better interior=higher price. I will reserve my judgements till when the car is released but I'm optimistic.
Any news on possibility of hood vents? Something like what the SRT's have?
Hmm, not that I know of. I think what you see is what you get at this point.Any news on possibility of hood vents? Something like what the SRT's have?