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Hey guys,

I have the DH ported head, and I am in the process of porting the stock exhaust manifold gasket to match the larger ports on the head. I was almost giving up on this project, but I've gotten alot of help from members here like guns, djmota, opto, and others.

Tools needed:

Dremel with at least 35,000 rpms speed
Grinding attachment (aluminum oxide)
masking tape
compressed air
Full goggles
Earplugs
Face mask

First off, this is a very time consuming process. It took me an hour to do just one port, but you'll get good results from taking your time. The dremel I bought was $40 from Lowe's and has two speed settings. It also came with the grinding attachment.



Here is a picture of the stock gasket placed over the exhaust ports on the cylinder head. You'll want to match up the gasket exactly with the screw holes and use masking tape to secure it.



Now put on your safety gear before getting started!



Now turn on the dremmel to full speed and get a feel for how to hold it. You'll want to lightly grind away in circles. The metal gasket may become hot, so don't touch it as you're going. Basically I ended up grinding down until the ports were even and smooth.

Look at those sparks fly!! Careful, they'll burn your arm.



Here is a comparison of ported vs stock:



Now with two done. I'll have to work on the other two tomorrow. About halfway through the first port, I had to stop and take it off to grind down the burrs of metal that accumulated around the edges. Make sure that when you take the gasket off, you make sure to put it back exactly how it was before.



Now you will have metal shavings inside the head ports. Obviously, you want to clean this up. I put masking tape over the hole and blew compressed air in through a small opening so that all the shavings stuck to the tape. Then blow it out a few more times to be sure it's clean.

I took the ported gasket and matched it up to my HP replica top portion header. Luckily, the new ports I made on the gasket matched the header ports. So I don't have to port the header at all! Sweet.



Well, hope you enjoyed this little DIY.

 
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nice

 
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tellus if you notice a difference when you get it installed!!!

very nice

 
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Very nice!


Oh, and I moved it to Tech, it's better suited there than FI....

 
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Thanks. I'm gonna post more pics if I get the header to port correctly. It turns out that the DH head ports are off center. So I'm gonna end up having to port more material off the header unfortunately.

Anyone know if it will cause a problem with the header port being larger than the head port and gasket on the bottom?

 
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Your the man. Looks like you are the first one to do it right and port match everything. Let us now how it goes once it is all bolted on. Glad to see that you stuck with it.

 
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gearbox... your the man... i read most of your threads and post...all i gotta say is you get crazy props from cause you have the ***** to apply the knowledge you find and take a chance to fix something that most of us would have prably gone and paid crazy money for.. You get madd respect.. for me and maybe alot other members on this site.. hope it works well.. good luck..

 
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good luck!!! I really hope you know what your doing and I hope DH didn't mess the head up beyond repair...The first pics you posted of the header looked kinda jacked up to me...The exhaust ports looked off center and too big at the top....I would try to find another head for cheap and have it done right...If it's done right, you will notice awesome gains like I did...Good Luck@!!!

 
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speaking of gains cwick187 did you ever get your fuel tuned at the dyno. If so how much HP and TQ .

 
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Cwick187, you're right. The exhaust ports ARE off center. That's why I have to port the header. The ports I made on the gasket using the head as a template are the same size as the header, buy they don't line up.

Here's what I mean. This is with the gasket put on properly, with those two rivets just on the outside of the seal. If I were to slide the gasket down, the holes would match perfectly (but then the head won't go on properly).

 
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Yeah, so you noticed...Maybe you can get all the kinks worked out..As far as my tuning, I go Saturday the 29th to get the VAFC II tuned with the cam gear...It runs great, but you can tell that it needs to be tuned. I'll post when I get it tuned again

 
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I did one port already and I have to let the dremel cool down. So now at least it slopes inward instead of a direct block of the air passage. I didn't want to go down too deep because of the welds.

cwick187, is your head milled at all? I heard that the DH heads are milled 1mm over the .2mm stock. This raises the compression and will most likely throw off the cam timing. So I guess I'm gonna get an adjustable cam gear. Is it safe to drive like this without tuning it?

 
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All done!! Alot of work, but I got all four header ports finished and alot of cleanup afterward.

 
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Yeah, it was milled, but not 1mm....My exhaust pops a little when at idel so the timing is a tad off. Damn!! He went 1mm over...That's a little too much IMO

 
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Ok gearbox, looks like ur gonna beat me to this install. LoL. Greta DIY though.

 
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Hehe. Projected install date: May 28. Then I need to get tuning, and possibly a cam gear to correct timing.

 
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how much gain will this do..?

 
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I guess we'll find out. I should be getting the volant cold air intake soon to go with this. Exhaust is still stock except for muffler.

After tuning, I'm hoping for at least 20whp gain.

 
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and then open the exhaust and intake mani, and u should be pushing quite a bit more.

 
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Only problem is a catback exhaust is gonna be LOUD with the head ported. That's why I'm steering clear of that.

So why does intake mani porting? Or can we DIY?

 
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I'm thinking you should buy a few extra exhaust ports or whatever its called, and port them. And start selling them.... so people who are afraid to do it can buy it from you!.

 
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Umm, it's called gasket matching...

 
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It was seriously alot of work and not something I would do again.

btw, I just installed the k&n fipk intake. It's pretty nice, but not much gain--yet. Ported head gets installed this weekend!

 
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.... for the ones who do not have a ported head, but a bigger port header would it help to grind some of the gasket as well to improve the flow of the header/head connection? Didn't think there was a bigger hole diff for the header / head connection and then the gasket restricts flow is there?

 
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The stock ports on the head are tiny, so matching the gasket to the header won't do anything. Even a bigger header won't do much.

 
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ok thanks just making sure--

 
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What other engine mods do you have gearbox. I was thinking about porting and polishing my stock headers and then doing the same thing you did. I just didn't know if that work needed to be done after some prior mods. Since it's been 3 months, how's it working for ya?

 
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Check my profile for other mods. Really the biggest one is the port work on the head, then the matching header, intake, and a bolton exhaust. It feels good for an auto, but still needs some dyno tuning.

You don't need to port the header unless you've got port work done on the cylinder head.

 
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So boring out the cylinders causes more compression, which can be dangerous to your wall. So say i bore everything bigger (cylinder head, ex man, and gasket) is performance going to be worth the hassel?

 
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I can feel a bit of difference. Nothing to jump up and down for. If done right (I don't think mine was), it works great. Someone here almost reached 140whp with a ported head and valve job with some other boltons and tuning. This doesn't increase compression, only milling does (grinding down the mounting side of the head). Honda recommends no more than 0.2mm, but I think mine is 1mm. Oh well.