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Updated: Ported and polished my head

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athlete3344

10+ Year Contributor
347
17
May 1, 2010
Tampa, Florida
I figured Id post up some of the recent work Ive been doing.

About a month ago I started constructing a valve spring compressor out of salvaged pipe, which I welded with an old arc welder I have access too. Overall, its not a bad tool, but can use some improvement. Anyway, the goal was to get all the head components out so I could port and polish the intake and exhaust sides, and polish up the combustion chamber.

I used Jafromobile's youtube video - 204 (or maybe 206) Porting and Polishing the Cylinder Head. I think it turned out pretty well. There are a few spots where I should have spend a hairs more time with the 80grit, but overall, it was a huge huge improvement over what was there.

If anyone has any questions, let me know, but Jafro does a pretty good job covering all the main points.

When I get my hands on the intake gasket, I will be enlarging the area a bit, and going over the outside of the runner slightly, but that area is much easier to work with compared to the valve side. I would recommend doing this before going through the hassle of porting and polishing.

Overall time spent grinding (and listening to the damn air compressor) was about 8-9 hrs. I expect the exhaust side to take about 12, and the combustion chamber to take about 6 or 7.
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Update - Did the exhaust side today and redid the intake side. I tried using a die grinder with the buffer wheels on the first go around with the intake side, and didnt really do as good as a job that I could have. The final passes with the buffer wheels were performed with a dremel - it was much much easier and came out a lot better.

Exhaust port before
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Exhaust after
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Intake redone:

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Great job! I wonder if someone has a before and after dyno of this mod.
 
This "jafro" guy is AWESOME. I watched 2 of his vids. Totally forgot about him. You've convinced me to do mine. Then all i need is the machinist to cut the seats for the 1mm OS valves. This is some serious work and i really like how he impresses that upon the viewer during the video. He says (paraphrasing) " this really doesnt do the work justice. What you're seeing in under 7 minutes is actually 8 hours of work". Thats an honest and practical comment. And IMO, his voice is not annoying at all, seems trivial, but that helps communicate information better.
 
don't worry so much about the polishing. The gains are in the porting. Great Job

I thought the biggest gains were just from removing the major casting flaws. Should the intake be gasket matched or is that overkill? I know the exhaust side needs much less work compared to the intake but i'd like your opinion on it as well. Thanks
 
don't worry so much about the polishing. The gains are in the porting. Great Job

The reason why I redid the polishing was I could see a huge difference between the exhaust side and intake side after only the 3rd pass on the exhaust side. The other reason why I wanted to really get it to shine was I noticed a lot of carbon build up in the exhaust side, and it was literally piled up. I wanted to reduce the chance that carbon would have to stick in the exhaust to avoid the stacking.

Im not quite happy with the exhaust, as there are very small pittings through each runner. They will remain there as I do not want to remove too much meat from each runner.

This "jafro" guy is AWESOME. I watched 2 of his vids. Totally forgot about him. You've convinced me to do mine. Then all i need is the machinist to cut the seats for the 1mm OS valves. This is some serious work and i really like how he impresses that upon the viewer during the video. He says (paraphrasing) " this really doesnt do the work justice. What you're seeing in under 7 minutes is actually 8 hours of work". Thats an honest and practical comment. And IMO, his voice is not annoying at all, seems trivial, but that helps communicate information better.

I really enjoy Jafro's videos. Hes detailed when he needs to be and very direct. You literally cant mess up by using his videos as a goby unless you get careless. The head will be going to a machine shop as soon as I finish up the combustion chamber. So far, theres about 30 hours of work into it. From what Ive noticed, the majority of my time spent porting was using the 80 grit - atleast 60% of the total time involved. If I do another head in the future, I will definitely spend a lot more time with the 80 grit now that I have some real work experience.

I thought the biggest gains were just from removing the major casting flaws. Should the intake be gasket matched or is that overkill? I know the exhaust side needs much less work compared to the intake but i'd like your opinion on it as well. Thanks

I know he mentioned not to port match the gasket, but what I ended up doing was a mix. I put the gasket on the head, and simply rounded off the edges so it was a smoother transition. I didnt remove any meat past 1/4" - 1/2" into each runner. Basically just enough to get a slight ramp.
 
The point of this thread was to simply give a real life example of porting and polishing a head using Jafro's video. Im not trying to run a 8 second car, all Im doing is trying to clean up my head, prevent future carbon related build up, and make it a bit easier for my engine to breathe. The head has to have a valve job done, so this was a "while Im in there" bit of work, as Jafro puts it.
 
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The point of this thread was to simply give a real life example of porting and polishing a head using Jafro's video. Im not trying to run a 8 second car, all Im doing is trying to clean up my head, prevent future carbon related build up, and make it a bit easier for my engine to breathe. The head has to have a valve job done, so this was a "while Im in there" bit of work, as Jafro puts it.
Don't worry so much on the intake. work on the bowls
 
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Correct, just curious Kris, but have you watched the Jafro video referenced earlier on?

He make specific note that the 1g intake size was large enough to support some ungodly amount of HP, and not to bother enlarging it. Instead, just focus on removing the casting marks and the porous area in the bowl. I suggest watching the video to get an idea of what I have actually done, since it seems like you are arguing against enlarging the intake runners, which wasnt done.
 
Im thinking just cleaning the combustion area and then removing the rough casting flaws. I dont know if i could spend that kind of time on the head, but im only after 650 at the crank. Not so detailed as OP's, though that is a beauty and i bet it flows damn nice.

To Nitrouschris: I too have read the stock unported head can make a TON of power. There has to be a reason to clean it up a bit though, right? I mean, albeit relatively small, there absolutely has to be benefits to doing that work. Again, might not be a big difference, but a difference nonetheless.
 
Correct, just curious Kris, but have you watched the Jafro video referenced earlier on?

He make specific note that the 1g intake size was large enough to support some ungodly amount of HP, and not to bother enlarging it. Instead, just focus on removing the casting marks and the porous area in the bowl. I suggest watching the video to get an idea of what I have actually done, since it seems like you are arguing against enlarging the intake runners, which wasnt done.
I have seen it and even pointed out something on the built of that head to him after one of the videos. Also if I remember right that is a 1.8 head and that head has smaller ports. I believe 3cc a port diff for a 2.0 head
 
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Im thinking just cleaning the combustion area and then removing the rough casting flaws. I dont know if i could spend that kind of time on the head, but im only after 650 at the crank. Not so detailed as OP's, though that is a beauty and i bet it flows damn nice.

To Nitrouschris: I too have read the stock unported head can make a TON of power. There has to be a reason to clean it up a bit though, right? I mean, albeit relatively small, there absolutely has to be benefits to doing that work. Again, might not be a big difference, but a difference nonetheless.
On intake just remove casting marks and if there are any high spots lower them.
 
+1 ^^^ on his comments. much attention will go into the bowl areas, short side turn, and combustion chambers. After the oversized valves are cut in, you may want to back sure that you dont need to blend in any the machining material left by the bore hog. May not be anything to worry about with 1mm oversize. Im used to making big jumps in size on standard size valves....fwiw the polishing looks good though
 
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This thread is Jafro approved! :thumb: ...and I should be asleep.

Very nice work Boost97gst! All of the advice here is spot-on. Especially nitrouskris' comments. Bowl work IS more valuable than any sort of polishing. Especially on the intake side. From what I see, you're doing it right.

Your valve selection piques my curiosity, though. Why are you using 1mm oversized valves? You wouldn't be planning to shift between 8000 and 8500 RPMs with a turbo that spools at about 5000 RPMs would you? You should follow through the links in my calculating compression video about the Lovell gas factor prior to committing to that valve job. Either find valves that are sized appropriately for the turbo you're going to use, or use the turbo that's sized appropriately for the valves you selected. You may already be doing that, but I just want you to get the most out of your fuel. ;)
 
This thread is Jafro approved! :thumb: ...and I should be asleep.

Very nice work Boost97gst! All of the advice here is spot-on. Especially nitrouskris' comments. Bowl work IS more valuable than any sort of polishing. Especially on the intake side. From what I see, you're doing it right.

Your valve selection piques my curiosity, though. Why are you using 1mm oversized valves? You wouldn't be planning to shift between 8000 and 8500 RPMs with a turbo that spools at about 5000 RPMs would you? You should follow through the links in my calculating compression video about the Lovell gas factor prior to committing to that valve job. Either find valves that are sized appropriately for the turbo you're going to use, or use the turbo that's sized appropriately for the valves you selected. You may already be doing that, but I just want you to get the most out of your fuel. ;)
Just on Tuesday I told someone to look at your video on valve spring install height.
 
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