My first stab at head porting...
10-29-2007, 11:57 PM
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My first stab at head porting...
After many late nights here and there, I finally finished this PITA project. Here are some pics of my handywork 
Time to get it back in the shop for re-assembly. I'm tired :sleep:
Time to get it back in the shop for re-assembly. I'm tired :sleep:
Last edited by PacificDude; 10-29-2007 at 11:59 PM.
10-30-2007, 10:01 PM
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For those who might be interested in the details, this is just a stock head for the D16A6 on my CRX. I've been needing to replace my head gasket and figured I'd swap out a head while I'm at it. So I picked up a spare head and went to work.
Originally, a friend whom has the professional experience, tools, and flow bench access, was going to do the work...but scheduling wasn't going to work out. So I asked for guidance and went to work myself. As you can see, the exhaust ports and combustion chambers have been polished. The intake ports on the other hand are not. The idea is you want the air to 'swirl' into the cylinder. The basic idea is that an engine is a large air pump, and the more efficiently you can get the air to flow, the more power it can produce.
As an addition to the head work, all the ports are port-matched to additional intake and exhaust manifolds to better improve the air flow.
I guess we'll see how it all works out. I'm told I will definitely notice an improvement in throttle response and will see marginal power gains. I have a tuneable PM6 ECU so I can get it all to run efficiently. I know I won't see the kind of gains I would get from a motor swap, but this will be a great learning experience for when a swap does happen.
Just in case any of you have never seen a stock intake/exhaust ports, here was what my starting point looked like...
The surface of an exhaust port is the same as this intake port. The combustion chamber surfaces aren't all that smooth either. There are seams in the ports that are left from the casting process, and smoothing those out while not taking away too much material, or disfiguring the port, was probably the hardest part. This project was not easy and I wouldn't recommend it for the novice tuner. I'm sure it would have been a lot easier, and faster, if I had all the right tools. Quite frankly, next time I'd rather have the pro's do it, considering the amount of time I spent. The experience though has helped me appreciate the meticulous preparation and execution it takes to do this kind of work. :happysad:
Originally, a friend whom has the professional experience, tools, and flow bench access, was going to do the work...but scheduling wasn't going to work out. So I asked for guidance and went to work myself. As you can see, the exhaust ports and combustion chambers have been polished. The intake ports on the other hand are not. The idea is you want the air to 'swirl' into the cylinder. The basic idea is that an engine is a large air pump, and the more efficiently you can get the air to flow, the more power it can produce.
As an addition to the head work, all the ports are port-matched to additional intake and exhaust manifolds to better improve the air flow.
I guess we'll see how it all works out. I'm told I will definitely notice an improvement in throttle response and will see marginal power gains. I have a tuneable PM6 ECU so I can get it all to run efficiently. I know I won't see the kind of gains I would get from a motor swap, but this will be a great learning experience for when a swap does happen.
Just in case any of you have never seen a stock intake/exhaust ports, here was what my starting point looked like...
The surface of an exhaust port is the same as this intake port. The combustion chamber surfaces aren't all that smooth either. There are seams in the ports that are left from the casting process, and smoothing those out while not taking away too much material, or disfiguring the port, was probably the hardest part. This project was not easy and I wouldn't recommend it for the novice tuner. I'm sure it would have been a lot easier, and faster, if I had all the right tools. Quite frankly, next time I'd rather have the pro's do it, considering the amount of time I spent. The experience though has helped me appreciate the meticulous preparation and execution it takes to do this kind of work. :happysad:
Last edited by PacificDude; 11-01-2007 at 08:28 AM.
11-01-2007, 01:25 PM
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Wow good job man. It looks great. Seems like it would take a while. Would you be able to elaborate a little bit on the process of it all? I'm interested even though I understand how hard and how much work you put into it.
11-01-2007, 04:07 PM
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I'll share a short version of the process, since explaining the whole thing feels like trying to give a haircut over the phone.
First I started taking down material to get rid of the casting seams you can see in the last pic. I used a large carbide bit to get the big spots, and a smaller one to get near the valves. I used an assortment of dremmel bits to get the inner walls uniformly round.
To port match, I got both intake and exhaust manifold gaskets to use as templates to know how much material I could safely take off. So starting with the head, I took off enough material on the head, then the manifolds till they matched up with the gaskets. During the process I would put the parts together and peer up through the valve openings to see how I was doing with the matching. Then I would make adjustments as needed.
Next I started sanding the port walls with small pieces of 80 grit sandpaper. This is done with an in-and-out motion. The reason for this was to get rid of any lumps and wavy feeling of the inner surface. Once the port walls were uniformly smooth, I started using finer grits of sandpaper going from 80 gradually to 800. I did the same sanding process on the combustion chambers. After the 800 grit, I used a polishing wheel on the dremmel with polishing compound. To finish it off, I used some Never Dull.
The intake was slightly different. Instead of polishing, I stopped sanding at 120 grit.
I hope that gives a good mental picture of the whole project. I wish I had a flow bench readily available to really get it done right. So next time I'll just have someone else do it that has all the right tools and know-how. At the very least I can appreciate the work they do
.
Last edited by PacificDude; 11-01-2007 at 06:12 PM.
11-06-2007, 11:34 AM
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Great job man, by comparison I really half-assed my port/polish job. I didn't get the finish you did, I just went through about 50 dremel wheels and smoothed it out a bit.
I had a builder tell me once that with newer automobiles, especially hondas, port/polishing is completely unnecessary and can even reduce volumetric efficiency. The idea is that they're so near perfect anyway there's not a lot we can do to improve it. He green-lighted the port-matching, though.
-Russell
I had a builder tell me once that with newer automobiles, especially hondas, port/polishing is completely unnecessary and can even reduce volumetric efficiency. The idea is that they're so near perfect anyway there's not a lot we can do to improve it. He green-lighted the port-matching, though.
-Russell