Port Match, Bowl Cleanup and Exhaust Port Polish Project

12-23-07:

I started the port work on the driver side today. First, I covered the holes into the water jacket with gaffer tape. Gaffer tape is like duct tape, but does not leave sticky goo deposits when it is removed.

Here is what the intake ports look like before any work is done on them:

Here is How I marked the intake ports for port matching:

Here are the intake ports after they were marked:

Here is how I ground the ports with a Dremel tool with a sanding drum:

Here are the intake ports after they were ground:

Here are the bowls before any bowl work:

Here are the intake bowls after grinding:

Here are the exhaust bowls after grinding:

Next, I checked the Fel Pro exhaust gaskets against the coated JBA Shorty headers to see how well they match. The good news is that I was pretty impressed with the size of the ports on the JBA Shortys. They came pretty close to matching the exhaust gaskets as you can see. However, I was not very impressed with the quality of their finishing work, which you can also see. The welds are very rough. I'd smooth them, but that would remove the coating, which I do not want to do. If I had it to do over again, I'd ask JBA if they could ship them to me uncoated for port matching, and then let me ship them back for coating. Regardless, the ports match pretty closely to the exhaust gaskets as you can see.

Next I checked the exhaust ports in the head to see how close they are:

I marked them in preparation for grinding:

It got too late, so I quit for the night.

1-26-08:

I started the rough grinding on the exhaust ports of the driver's side head today. Since so much metal (about 1/8") had to be removed from around the exhaust ports, I switched to using impregnated fiberglass cutoff wheels to do the rough work.

I ground about 3/4 of the metal away with the cutoff wheel, and went some distance into the port to ensure no restrictions or sharp angles in the port. I also knife-edged the split between the ports.

Next I used 60 grit sanding drums to finish the coarse port work.

Since the cutoff wheels and the 60 grit sanding drums leave grit marks around the port, and the rough work is pretty rough. The next step is to use 60 grit sandpaper.

Cut it into small squares and folded up to sand in the direction of the exhaust gas flow. This puts 60 grit scratches in the direction of the port, but it also lets you know where you have cut very deep with the Dremmel tool. The deep areas will show horizontal scratches in spots surrounded by the vertical scratches you are putting into the port. This step is the hardest, because you want to smooth the port till those horizontal marks are gone. If you have the patience to do this at this point, the polishing process will go a lot easier after this step.

I decided not to go all out and have the valve guides removed, so I can't polish right up to the guide, but I am hoping that won't hurt me too much.

This picture has a pretty good example of the scratches running across the port on the left after being smoothed with 60 grit sandpaper. You can see where I still have work to do. You can also compare it to the un-sanded rough port on the right. If you zoom in to high resolution on this picture, you can really see it well.

10-20-08:

I have been slowly working the driver's side head. The first round of polishing after the port shaping is the hardest because it leaves deep scratches that take a lot of 60 grit sanding to get rid of. Depending on the location, it has to be done by hand. Here is the first port to be nearly done at the 60 grit level next to the next one that is still just rough worked. You can see the difference. I have been using pink Dremel stones (number 952) to do some of the finer grinding on some of the deep scratches. The stone galls, but not too fast.