It is hard and costly to get the cylinder head intake ported because of the integral intake manifold cast with the head. The casting has to be cut or machined off, the intake ported, then the head drilled and tapped so a ZZ fabrication or Banks big hoss manifold installed. It seems like extrude hone would be a way to do it without having to machine off the cast manifold. Has anyone done this or looked into it? Would this help equalize flow to the cylinders? How much does it cost?

 

I wanted to do the same thing. But i would think it would be pretty expensive. I saw where banks is selling their new intake and another company is selling a high performance cylinder head with the intake cut off already. Cant remember the name right off the top of my head.

 

I had this done to a 12 valve head a couple years ago at Extrude Hone (the company) now renamed Ex One,just south of Pitsburgh PA.I was less than impressed with the results.While the valve bowls were mirror finish ,very little if any material was removed from the runner.The media was pushed thru from valve side and obviously looses resistance (pressure) as it travels thru the runner.This process would be more of a finishing operation,performed after manual porting was done.Oh and did I mention it cost $1000,since the head was on the machine for two days.I cant say I would do it again.Heres a few pics (not very good ones)

 

Thanks for the pics. Thats a shame. I wouldve assumed that would have been a viable option.

 

I have always felt extrude honing is really only good for removing burrs and such and smoothing the ports. Never felt it was good for porting. To me, it was something you'd do after the port job to take down any sharp edges that may have been left.

 

Thanks for the replies and the pics. I was under the assumption that they were able to remove more metal but maybe that is only for aluminum. I was hoping that it could be an account-friendly option. I also didn't realize it was that time consuming, 2 days!, the abrasive media they use must not work well on cast iron.

 

Hello,

Most anyone looking to make some power does not consider that process. Drag & circle track guys found out that it's a minimal gain an sometimes none. If a head porter leaves any high spots I doubt he is a professional.

Damon

 

I was just looking for another option. To port the cummins heads the cast on manifold must be machined or cut off then you have to get the head drilled and tapped to install an after market manifold. That adds a lot more to the cost.