I did this a couple years ago with my Mercedes OM603 six cylinder
turbodiesel, when I was swapping in a new head.  I port-matched both the
intake and exhaust ports/manifolds, as well as cleaned up the surfaces
around the valve stems and such.  I ended up removing lots of material, so
it took me quite some time to do each port uniformly.  I can't quantify the
benefits gained, but these changes along with adjustments to the injection
pump and the addition of an intercooler and propane injection all helped to
drop my 0-60 times from ~12 secs to ~7 secs.  Every little bit helps to
improve efficiency, especially on a small displacement engine like a 1.9L

Casey
'87 300TD
'94 100CSQ
'89 Bluestar

On Jan 21, 2008 5:01 AM, Giasson, Pascal (DNR/MRN) <Pascal.Giasson@gnb.ca>
wrote:

> I tried to find some "how to" and benefits info on port matching the
> Vanagon heads to the intake manifolds with no luck.  My intake manifold
> openings are smaller than the gasket openings (gasket between the intake
> manifolds and the heads) which have openings that are slightly smaller
> than the head intake port opening.  I used my Dremell with a burr bit
> and also a large sanding drum to open the ports on one manifold to match
> the gasket...about 1.5 hours of work.  I used a fluted pen in the two
> bolt holes to line up the gasket on the intake manifold and then used a
> permanent marker to outline what needed to be ported out.  I tried to
> make the porting out as smooth as possible up the manifold.  I don't
> think I want to match the gasket to the head as the manifold will again
> be smaller than the gasket and I'm not sure it is worth the work on my
> 1.9.  Intuitively it makes sense to match the ports but this type of
> work is probably more important on a high performance engine that would
> suck lots more air at higher RPMs than my 1.9 Westy?
>
>
>
> Pascal
>
> '84 Westy
>