i have a couple of questions regarding porting (myself) my spare inlet manifold i am in the process of reconditioning.

what are the bennefits/gains ?

how much do you actually grind out ? i see it has ridges near the entry so i presume they need to be smoothed out.

do i open up the inlet holes a bit or just smooth it out as much as possible ?


as you can see i'm new to this part of the process and am going for cackle black when it's done with some inlet manifold spacers.

i'm looking at everything i can do before i get my next remap.

if it's of any importance my spec is in my garage.

any comments and advice welcome thanks.

 

The aim is to match the shape of the inlet manifold runners to the ports in the head. IIRC the best idea is to scribe the inlet manifold "holes" to show you where they don't match too well. Then blend and smooth as required.

The clever bit is flow-benching the results to learn where metal can be removed near the valves to aid breathing....

IMHO

dunx

P.S. Going too smooth can reduce fuel atomisation, some roughness to the port walls is thought to be beneficial.

 

thanks dunx