DIY Head Porting

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Sohcturbs
Posts: 94
Joined: Fri Nov 24, 2006 10:29 am

DIY Head Porting

Post by Sohcturbs » Tue May 06, 2008 12:28 pm

DIY HEAD PORTING

This is what I did. I strongly recommend that you get a second head before you attempt this. I noiticed quite a big difference in the heads, despite both being 15M heads. I really should have used the other head I had that was on the car, as the valve guides were much more unshrouded which would have made the job a hell of alot easier. Though, in saying that, that head had big ridges in the ports instead. With the heads I had where the valve seats were put into the head, in the ports, were lips that were noticeable though small. Unfortunately it's not a perfect world and in saying this it's not going to be a perfect job if your doing it at home.

I have no real world proof to show whether this is of benefit at all other than the shop that did the work on the block saying that it looked like it would flow well and doing what I logically thought should work with a bit of research along the way.

I stripped the head down and took all the parts to the shop to be cleaned and returned. I also got them to pressure test it to make sure I was working with a good head before I started.

The head back from pressure test and clean:
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There is a great site on head porting here [color=green]http://www.sa-motorsports. ... px[/color]. This tells you pretty much everything your going to need to know.

The thing with this is unless you've got a big compressor this is going to take some serious time to get it all done. I took the cheap route and didn't buy the kit. I had a carbide burr and 5 porting rolls. Of which I still have some left. But would recommend the kit if doing it again it would have made life much easier. Especially in those tight places. Right tool for the job etc...

The grinder I used and carbide burr:
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Porting rolls and mandrell:
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Dive cylinder with grinder:
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I started using high pressure dive cylinders, but as I only had two cylinders got sick of getting them filled or running out of air all the time, naturally half way through what I was doing. These air grinders use a LOT of air.

I then bought a compressor from super cheap auto it was cheap, noisy, and i think the constant running has just about killed it. I would run it up from empty use it till empty again wait 5 mins do a bit of vacuuming to clean up the mess and start again.

Supercheap compressor:
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Set up here now is the key I had a sturdy work bench, an old vacuum cleaner, the compressor, a radio (must have), and a box with a desk lamp on it so you can see clearly what your doing.

With the exhaust ports we matched these up to the exhaust manifold flange before we started fabricating the exhaust manifold. We could easily bolt it on, then grind up to the shape allowing a perfect match.

Exhaust side with matched ports:
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The inlet ports were not so easy. I ordered a gasket set and set this up and traced around inside to make my matching lines. I then reversed the gasket and proceeded to do the same to the inlet manifold. There is a big difference here. I ended up grinding away quite a bit of material.

Inlet ports marked on head and manifold:
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In this particular head there was a lot of rough area around the valve guides. I started using the porting rolls as everything you read says to not use the burr. I have to say i found the burr very effective. It takes less time and provided your careful the finish comes up nicely when sanded over later on. Once I'd roughed out the bowls I put the burr away and started on the paper rolls. This took a long time trying to get a tidy shape and uniform finish.

Starting on the bowls exhaust side:
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A bit further on using only the carbide burr to take off the bigger ridges:
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Now starting into the inlet ports, working on the bowl area:
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Matching the inlet ports:
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Grinding the ports of the Inlet manifold to match, later decided it was a good idea to remove the injectors and seperate the bottom of the inlet manifold off:
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Starting to come together a bit nicer now:
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Exhaust ports starting to show some shape:
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These last little bits are real hard to get to, this is where i think the full porting kit would really come into it's own. At a stretch you can grind down cylindrical rolls on a bit of steel to get in there:
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With this completed I then moved onto the most important area the radius into/out of (depending on side) the cylinder. This is quite tricky to get into and works best once your rolls have worn down a bit. There is a real knack to keeping a nice shape to this and it takes time. A good light is your friend here and your forever moving the head around. I used a roll of tape under the head just to give the back edge some elevation to get a better angle. Be patient if you go slow and be thorough you'll get a good finish here.

Using the tape to get different angles:
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Unfortunately I ran out of time so never got to flow the head as I had wanted to to see if I was going in the right direction. However, the workshop I went to does a lot of this work and said that they could tell just by looking at it that what I had done was in the right direction.

Fingers crossed with the 3 angle valve job my efforts will have given me the flow that I need to match the other components of the build.

Final product:
Image Image Image Image

Back after bead blasting ready to install:
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So that's the sucker. If you're keen give it a go. I'm not sure how much it cost me in fact probably more than what it would have cost to surrender the head and get it done professionally, but personally I prefer to do it myself. I must say it took a long time to get it to the stage I did. If you were real pedantic you could go to different grades of paper, but i was satisfied with the finish on the intake ports and exhast. Articles talk about getting a mirror finish on the exhaust, but I think that it's fairly difficult to do this in a real world situation and don't think it would provide much gain. Might be easier in a huge 440 BB V8 port, but not so easy on the ports we're working with.

Hope this helps someone else out in the future i'd love to hear people's thoughts. I may since i'm running it in stock give it a dyno run and see if it makes any difference extrapolating it back compared to a stocker. Still seems a bit unscientific.

Cheers,

Dan
Last edited by Sohcturbs on Tue May 20, 2008 7:59 pm, edited 3 times in total.

Sohcturbs
Posts: 94
Joined: Fri Nov 24, 2006 10:29 am

Post by Sohcturbs » Mon May 19, 2008 5:31 pm

Pictures added and finished...

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Kimmo
Posts: 2285
Joined: Thu Nov 02, 2006 8:40 am
Location: Footscray

Post by Kimmo » Mon May 19, 2008 6:36 pm

Nice one. Pity the pics are so small; can't really see much...

Sohcturbs
Posts: 94
Joined: Fri Nov 24, 2006 10:29 am

Post by Sohcturbs » Tue May 20, 2008 6:28 am

Cheers Kimmo,

Appreciate the feedback. It took a dam long time to get those pictures over and at least they are permanently hosted so won't drop off like the imageshack ones.

However they are all off my cardomain site so i'll see if I can link to the enlarged photo's.

*update* bigger pictures updated
Dan

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Kimmo
Posts: 2285
Joined: Thu Nov 02, 2006 8:40 am
Location: Footscray

Post by Kimmo » Wed May 21, 2008 1:02 am

Sweet, heaps better...

Nice article.

PAC_ET
Posts: 81
Joined: Thu May 14, 2009 8:32 pm
Location: Sydney

Post by PAC_ET » Sun Nov 07, 2010 8:27 am

here's my attempt at head porting


used an electric die grinder, with two rounded carbide bits and one straight and a home made polishing bit
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my home made polishing tip, just a 6mm copper tube and a cut in the middle at the end so i can insert some strips of sand paper
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inlet port
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exhaust port
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finished in one day :D

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