Im sure it has to do with emissions, fuel economy or something like that, but why does the Y8 head have humps in ever other intake runner? Like if you pulled out the intake valves and stuck your finger in the holes you would feel that ever other intake hole had a hump. When I was talking to the guy thats going to be P&P my head he wasnt to sure cause the Z6's and B series arnt that way. So im just curious if anyone here knows why.

 

Just wanted to see if theres anyone out there that knows this that didnt see this thread.

 

So with all the vast knowledge on H-T theres no one that has an answer or a theory to this.

 

As far as I know, those humps were put there to create "tumble" at low rpm, for better low rpm torque. That is why for a straight performance application, most people prefer to use the d16z6 head.

 

Thank you. Thats what I and the guy thats porting my head thought. So wouldnt you just be able to remove them for the so called race application? I mean then it would be just like the Z6's. Or will it make the wall between the coolant port and the intake runner to weak?

 

Just wanting to see if anyone had an opinion.