Tech question- 1.6L head mods, porting
 

This is on a 1.6L 8v head, with TBI.
Inside two of the four intake manifold runners, there are "bumps" in the casting near the ends of the ports. These bumps are for vacuum ports that are running beneath them in the casting.

Question: How much of the "bumps" can be taken down without disturbing the vacuum post and f**king up the manifold? We got most of it down, and really opened the port up to match the head, but if it can completely be taken down, all the cooler.
Thanks.

Re: Tech question- 1.6L head mods, porting
 

Glenn, if those vacuum ports are for manifold vacuum devices, i.e. high vacuum at idle,then complete removal should be fine, If they are for ported vacuum off idle (like EGR) then it may not produce as much vacuum if they're gone.I think its for the PCV system, though.Check that service manual [img]images/graemlins/wink.gif[/img]

Re: Tech question- 1.6L head mods, porting
 

I know on the Sami's 1.3 head you really gotta watch how deep you cut , some castings are thinner at that point than others . See if you can find a junk one to try it on , then guage how well the casting halves are lined up on yours and cut it accordingly .
Sarge