If you're not familiar with the 2.1L let me give you a brief primer.
The 2.1L 4G6x is made by putting a 2.0L (88mm stroke) crank in a high deck height 4G64 block. The 4G64 block has a 6mm higher deck height and when used with "stroker" pistons which have a 6mm higher offset wrist pin, allows for the use of 162mm long rods opposed to the 150mm rods of a 4G64 or 4G63. This length is due to the 6mm offset + the 6mm higher deck height (6+6 = 12 = 162-150). A longer rod leads to a better "rod ratio" of 1.84:1 which reduces stress on the pistons/rods/crank/bearings.
Rod Ratios:
2.1L = 1.84
2.4L = 1.5
2.0L = 1.7
This helps to rev the engine VERY high. Most sources claim 11,000rpms as the redline.
Of course turning these revs is not particularly easy. All things need to be accounted for such as the valvetrain, cooling, lubrication and a transmission that can put it to use. Turning 11,000rpm and making power at these revs are two totally different things. Power will be made by closely examining all aspects of the system. Port size, cams, intake runner length, exhaust manifold design will all need to work together to make power at high revs.
It might be best to see what Honda guys are doing and just copy them.
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My plan is a bit of an aside, but I'd like to talk about it anyway
. I'm going to build a 2.1L non turbo motor. Bill is working on a dry sump system that I hope to use. I think with 11,000rpms controlling windage should gain me quite a bit of power. I'll also use ITBs on this engine and coil on plug.My last engine was built to be cheap and powerful and using my savings not doing tons of little things put into things like fuel management, cams and a turbo. With this engine I'm not going to make as much power, but I'd like to just have a wild non-turbo motor paying attention to all the small things like windage, valvetrain, porting, intake runner length, header design, etc. One of the biggest challenges is going to be finding cams that will make NON-TURBO power at these revs.
I plan on building the bottom end first and sorting out the ITBs, exhaust, cooling, first at normal (<8000rpm) engine speeds. Once I get that sorted out I will focus on the head and making power. I probably won't start this project until 2009, but it should be fun to plan until then.
