Originally Posted by
mc_chofo
Hello actually this info actually helped me out to understand more about modding engines. the thing is that i just bought a novarossi 3sct, and i want to make it just like the tunned version or even better, i don't want to make my way to that point too hard. i was thinking about doing some milling kind of drops on the piston sleeve, opening the upper part of the exhaust port 1mm each side, and at last i'm planning to remove those 2mm on the crankshaft hole of the side that closes. ´cause i don't what to screw the engine, does any of you know what i should do exactly to this nova 3sct to turn it into the tunned version? or what i shouldn't do to it to avoid screwing it?
i really appreciate your help.
Please don't.
You got a wonderful engine there, that will have gobs of power if your pipe and clutch is correct.
All the changes you mentioned above are guess work. You can not measure crank timing in mm, also, opening the exhaust by 1mm will give you approx. 15 ° timing change, which is way too much. If you are opening the exhaust port 1 mm to each side, your piston will catch the edge and your engine will be toast. The exhaust port on the 12-3 is very complex and works well as it is.
You cannot transfer any of the measurments, you might have read here to any type of engine. Below they are talking about .28 engines.
Leave it alone and be happy, or send it to someone like Murnan and get some reliable power.