This is not necessarily a comprehensive how to article, but more just a bit of a guide for a fairly simple process.

First up either make a gasket to fit on the head from scratch out of cardboard or gasket material (required if you have ported heads or street eliminators or the like that require gaskets that aren't off the shelf). If this is required trim the card to the exact shape of the inlet port.

In my case I used a standard type IV inlet manifold - it was slightly oversize in comparison the ports which was taken into consideration when match porting.

Next up place the gasket on the manifold ensuring you line up the bolt holes to check if you need to port or not!

I marked around the ports with black marker (engineers dye could be used but didn't have any - this sufficed).

Holding the gasket firmly in place, scribe around the inside - a proper scribe will help here...not a corner of a screwdriver or similar.

Here we are ready to go...

Using a tungsten carbide cutting bit in a die grinder enables you to take off material quite quickly (so go slowly!). I found some WD40/RP7 helped to stop the aluminium clogging up the cutting bit. I found a bit with rounded end helped to avoid cutting in any steps/edges into the manifolds.

I then used a sanding flap wheel to tidy up the harsh scratches left from the cutting bit - this one was 120 grit.

Ports were now done, I decided to ensure the manifold base was not warped. First off mark the base with dye or marker pen.

Find a perfectly flat piece of glass (not all glass is perfectly straight by the way). If you ever see a scrapped photocopier - its glass is perfect! Then using sandpaper (I started with 240, then used some 400 to smooth out any scratches) steadily rub the manifold across the surface until the dye/marker is gone (but don't go too nuts and take too much material off).

Even though these manifolds were new, I thought I'd check. Used manifolds subject to heat and overzealous manifold nut tightening would benefit greatly from this process.

There ya go....nice and flat.

excellent stuff

thanks :kiss

might do this to the 2L when i have it apart to fix the oil leaks

Well explained and interesting , cheers

Dan

just bringing the thread back out of the archives.

So the manifolds have now been matched to the gasket, but what about the head, did you also open up the ports?

Yep, sorry didn't have those photos because I didn't do the head work myself - that was outsourced so I didn't screw it up.

how far up inside the manifold did you go ? it only looks about an inch ,is that about right?

Because the amount of material I needed to take was relatively minimal, I only blended the manifold ports up to around 1-1.5 inches. If more porting was required on the manifolds, you would probably have to blend them higher up. For extreme applications, I've seen guys have to cut the manifolds in half to do the porting, then have them rewelded.

Thanks, great easy to follow directions. Will definitely follow this when I rebuild my 1800 and make my 1916.