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Discussion Starter · #1 ·
Hi friends!
Earlier I announced a topic about the kit camshaft for 6G75. It's time to do this for the 6G75. As always, I try to explain the principle of operation. It's hard for me to explain in English. But I will try to make you understand me.
 

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Discussion Starter · #2 ·
So. The 6G75 engine has a system of MIVEC, similar to 4G69. Moreover, this system operates on the principle of switching types of Cams of the camshaft. There is also a system with rotation of the camshaft (for example Evo 9). In this system up to 3500 rpm working one type of cams. After 3500 rpm the work enters the other Cam.

Look at the picture. Cam A - works after 3500 rpm (intake). Cam B - works on exhaust. Cam С - works up to 3500 rpm (intake).
 

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Discussion Starter · #3 ·
In the engine is like two engines. To 3500 rpm economical with low frictional resistance. After 3500 rpm the more powerful and torquey.
What do I do?
Produced completion of Cam A. Now I'll explain the principle.

Look at the picture. On a special machine, decreases the base radius of the Cam. This increases valve lift and the width of the phase. Thus, up to 3500 rpm, the engine will remain as before. And after 3500 rpm will be more powerful.
 

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Discussion Starter · #4 ·
Usually, this revision gives a 12-15% gain on top. I do it at an aircraft factory in the city of Perm. But that's not all. Also need to modify the rockers. Working on this Cam. If at the end of the rocker was the adjustment screw, then you can just adjust. However, the rocker mivec does not contain the adjusting screw.

After you did the regrinding of the camshaft and its base radius becomes smaller. Therefore, under the rocker will appear a gap.

Therefore, it is necessary to make a thicker roller. The wheel needs to be thicker for the same size, how much reduced base radius.
 

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Discussion Starter · #7 · (Edited)
Further, at the aircraft factory in the city of Perm, made rollers of larger diameter.



Camshafts are ground off Cams A. (-1.7 mm diameter). Accordingly, the rollers are longer than stock (+1.7 mm diameter)
left is stock, right is new.
 

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Discussion Starter · #8 ·
I originally thought that the duration of the opening of the 6g75 camshafts is the same as the 4G69. However, when I measured the shafts, I saw a difference.
duration 4G69 - 274 degrees
duration 6G75 - 264 degrees

Therefore, after the regrinding, the result is slightly different.
4G69 - 296 degrees
6G75 - 286 degrees
 

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Discussion Starter · #9 ·
the whole set after Assembly.

Now this package is going to Chile. We'll wait for Alonso to receive and install new parts on his engine. After that you will configure on the dyno. You'll see what a raise the camshafts give. That's all.
 

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Discussion Starter · #20 ·
Will these behave like normal cams below MIVEC? Would love a set but not sure if willing to sacrifice my daily driveabilty for the extra power.
The whole point of this revision, to raise the power and torque in the high side of the speed (RPM). Before the MIVEC rockers start working, everything works as before. When the MIVEC system is turned on, more air will now be released into the combustion chamber. Due to the fact that a higher duration. And higher the valve lift.

Of course, everyone decides whether to do something with your car. It's actually enough to drive a stock car.
 
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