I was reading in the new HCI and they were doing a valve job on a b16 head. They were porting the bowls too (getting rid of the nasty lip). I decided that this would be a good idea since I have a extra head that will be going on next season. I then proceeded to port and smooth the valve bowls (so no more lip between the seats and port). I only did the intake so far but it looks great (pics soon). On the B16 head it was good for about 10cfm more flow. Does anybody know what the porting would be good for on a DSM 2.0TC head? Thanks

There's only one way to know. Take it to a flow bench. Personally I think if you do not have a flow bench you should not be porting a head. Porting is so delicate...even if you increase flow you might seriously decrease velocity if you don't know what you are doing. Spend the extra money and have it ported professionally.

Originally posted by dyezak
There's only one way to know. Take it to a flow bench. Personally I think if you do not have a flow bench you should not be porting a head. Porting is so delicate...even if you increase flow you might seriously decrease velocity if you don't know what you are doing. Spend the extra money and have it ported professionally.

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Well see, I am not really porting it. There is a lip that I am eliminating. It smooths the flow not enlarges it really.

i remember when the dsm world was full of diy'ers...

getting rid of the step at the valve seat is a great idea, i just p/p'd my head and that was by far one of the worst things about the ports, i definately spent the most time there. other than that, do some clean up work on the ports, polish the combustion chambers, and knife edge the dividers (if you feel like it). if you stay on the light side you'll definately be going in the right direction.

and hey, you've got an extra head so if you feel like you lost power with the ported one you can always swap back

marshall

Originally posted by marshall
i remember when the dsm world was full of diy'ers...

getting rid of the step at the valve seat is a great idea, i just p/p'd my head and that was by far one of the worst things about the ports, i definately spent the most time there. other than that, do some clean up work on the ports, polish the combustion chambers, and knife edge the dividers (if you feel like it). if you stay on the light side you'll definately be going in the right direction.

and hey, you've got an extra head so if you feel like you lost power with the ported one you can always swap back

marshall

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Cool thanks That helped answer my question. Did doing that work to your head give you a bit more power? Did you notice a difference I mean? Thanks!!

i dunno yet, i did an intake mani and T3/T4 at the same time, just got it back on the road and it's still at 10.5 psi. at this boost i'm flowing almost as much air according to the s-afc as i was at 19psi on my 16g lots of tuning to do...

marshall

Originally posted by marshall
i dunno yet, i did an intake mani and T3/T4 at the same time, just got it back on the road and it's still at 10.5 psi. at this boost i'm flowing almost as much air according to the s-afc as i was at 19psi on my 16g lots of tuning to do...

marshall

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wow, that sounds like a pretty good setup so far. Yeah I agree, it would be hard to tell changing all that at once!

Originally posted by marshall
i dunno yet, i did an intake mani and T3/T4 at the same time, just got it back on the road and it's still at 10.5 psi. at this boost i'm flowing almost as much air according to the s-afc as i was at 19psi on my 16g lots of tuning to do...

marshall

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It's spelled "I".

wow, good job catching me on that...

i don't understand why being negative is thought of as being cool/intelligent on this board...ah well.

marshall

I think being in the Extreme Forum, some people expect a little extra effort like punctuation, grammar, etc.

I think he was also joking too a little. I dont think that was intended to be harsh. Anyway, thats great to hear the hard results there marshall on the new setup. Whats boost hit by? How is the low end? Im just curious with the intake mani and the T3/T4, I would think the low end would hurt some, but then again that's why I'm asking you to see how it turned out.

Originally posted by marshall
wow, good job catching me on that...

i don't understand why being negative is thought of as being cool/intelligent on this board...ah well.

marshall

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If I was going to be harsh, I would have simply deleted your post. I gave you a chance to learn from your mistake so it wouldn't happen in the future. I hope you take it as such, otherwise I will start deleting your posts. Read the rules. They are explicit.

Now on topic:

There is a constant fight between volumetric flow vs flow velocity. Ideally you want both: more flow with more velocity. Win-win. Unfortunately it's not always the case. The 2G-1G head swap is a prime example. The 2G head is well designed to flow decent air and maintain high port velocity. The 1G head has bigger ports to gain more volumetric flow but it also in turn hurts the velocity, and loses lower end torque.

Sometimes a good port job is distinguished from a bad port job based not on what is removed, but rather what is left alone.

Heres some good reading.

http://rehermorrison.com/techTalk/06.htm

http://rehermorrison.com/techTalk/16.htm

Y'all should be epoxying the overhang, not grinding a bulge into it.

I'm looking at a head now and I see what you mean about filling in the overhang with epoxy. The question is, how do I fill it so that it stays put and doesn't break off and get sucked into the engine? What's the best epoxy? I have plenty of JB weld sitting around!

Originally posted by pneumo
I'm looking at a head now and I see what you mean about filling in the overhang with epoxy. The question is, how do I fill it so that it stays put and doesn't break off and get sucked into the engine? What's the best epoxy? I have plenty of JB weld sitting around!

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I would like to know too why epoxy over grinding it off. I wouldn't want to take a chance of the epoxy falling off and either getting in the engine or stuck in a valve. Its not really making a buldge in it either. Its just smothing everything out. If you have the right tools (summit porting kit) I wouldn't think you would have any problems. At least I didn't. I'll post some pics within the next week or two of the progress so far. Thanks

Any word on what type of epoxy to use. A local shop told me " I think they use kop-coat". I dont want to go with a "think"
Jd

Originally posted by DSMRevolution


I would like to know too why epoxy over grinding it off.

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Since he hasn't responded; based on Groc's other posts around this topic, the issue is velocity vs. flow.