How to porting and polished of the HR cylinder head?

I doubt anyone has or will attempt this mod. Good luck to you

i'm not sure this has been done before, but i think i've read that the versa ecu is adaptive. meaning it may take a little while for the car to figure out what you did to it. then you should see the improvements.

jbeau said:

I doubt anyone has or will attempt this mod. Good luck to you

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thanks..my friend just did this mod on his MR18DE, and so far he got significant power, and he told me that he will help me to do this mod on my car...

Thanks all...:thumb2:

I'm considering it over the winter for my MR20 as well

jbeau said:

I'm considering it over the winter for my MR20 as well

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Good luck,bro... i will waiting for the report..:thumb2:

Lil Blue Versa said:

i'm not sure this has been done before, but i think i've read that the versa ecu is adaptive. meaning it may take a little while for the car to figure out what you did to it. then you should see the improvements.

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yap, you're right bro, the ecu is adaptive.. i had tried...:thumb2:

jbeau said:

I'm considering it over the winter for my MR20 as well

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If we keep our car for a while, we'll probably do this, too...

Let's do it,guys..

how long does it take for it to adapt?

yes please some one knock this out so ill know if its worth it haha

MizuShinobi303 said:

how long does it take for it to adapt?

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i had same question

asian_boy said:

Guys, i had port and polished my HR cylinder head, also slip the cylinder head around 0.5mm . and i found some difficulties,

on the dyno run, the power decrease 4 HP and the tq decrease 20 Nm after i did that works..

how the maximum limit in slip cylinder head on HR? and it just need to be polished only (no need to oversize the in and ex on the cylinder head )?

so i need your help,guys.. thanks..

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It could be something as simple as that the HR16DE engine was developed with the ports being the most effecient size to begin with. By making them bigger you slowed down the velocity of air which made the engine slightly less effecient.

I'm not saying that this IS what happened, but modern engines are made to be very effecient from the factory in order to meet the tough emmision requirements of EU and US.