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| Porting | |
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| Tweet Topic Started: Sep 10 2014, 03:38 AM (824 Views) | |
| crankcase | Sep 10 2014, 03:38 AM Post #1 |
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There is always talk of people wanting to port parts of their intake systems. There a lot of videos and advice on the subject. The aim is usually stated as trying to increase the flow. There are also many write ups about doing more harm than good, but I guess it also depends on what you are trying to. I've read that rough galleries increase turbulance and result in better fuel air mixing. I've also heard that polishing is benifical, but only when done in select areas. Is porting a complex thing to do for maximum results? Is special test equipment usually required to get good results? What opinions or comments do you all have? "She's ported and relieved and she's stroked and bored" |
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| Freeman | Sep 10 2014, 05:37 AM Post #2 |
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The Family Man
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I've ported stuff myself with relative success. Is it complicated? No. Is it complicated if you want to achieve maximum results? Yes, absolutely. I ported my exhaust manifold and turbo inlet. I ported the runners on the manifold and the flange on the turbo. I wanted them to match up better than they were. I used a dremmel and my finger. As for the intake, I haven't messed with it. But when it comes to something like this, cleaning the shavings off is something that should be done with extreme scrutiny. There is only so much a hobbyist can do. |
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| econoboxer | Sep 10 2014, 08:07 AM Post #3 |
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I am the one on the left.
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Intake side not as important to start with- work on exhaust side first. |
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| perfesser | Sep 10 2014, 09:09 AM Post #4 |
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Elite Member - Former Metro owner
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To do the job so you can sing "Little Deuce Coupe" doesn't take a lot of equipment, and you'll learn a lot of technique by the time you get to the last hole. Of course, by then, you've cut away enough material on the others that you can't go back and fix them! To do the job right, as TurboEF says, takes a flow bench and a good class in the fluid dynamics of combustion engineering. There are YouTube videos on how to build an inexpensive flow bench with a shop vac if you're into that, and while it's not as good as the benches we have in the labs at school, it's better than an uncalibrated eyeball. There's a lot of material on how to port for various performance requirements. Just stay away from the fanboy sites and focus on those that know what they're doing. Turbulence increases the mixing of fuel, but also increases the resistance to air flow. Polishing increases air flow, but doesn't do as much mixing. Is your combustion chamber adequate to mix the fuel/air charge on the intake and compression strokes? If so, you don't have to worry about the small amount of mixing that turbulence provides. The intake side runs a vacuum and moves a small amount of air. The exhaust side is under high pressure and the volume of combustion gases crowding around the exit is much, much greater. This is why, for the same effort, the exhaust side will yield more noticeable results. But take it slow and test frequently!! It doesn't take much to take too much! Define your goal in doing the porting, learn all you can about how to tune the manifold to achieve those results, make a small flow bench, and have a ball! Might be wise to start on some spare parts from the pnp first, though. There is a learning curve! Edited by perfesser, Sep 10 2014, 09:15 AM.
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| Old Man | Sep 10 2014, 09:25 AM Post #5 |
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A novice should be very careful. Stick to two things only. Gasket matching and smoothing casting marks. These two things can be done with only a good eye and a dremel grinder with no special equipment. This will give you the maximum increases with the minimum chance of 'screwing it up'. |
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| Freeman | Sep 10 2014, 09:26 AM Post #6 |
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The Family Man
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Exactly what I did. My cast turbo manifold had some obvious 'issues' that could be fixed relatively easily. Same could be said about the exhaust side of the turbo. Other than that, you should take the advice given by those wiser than me. You don't want to ruin anything.
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| 92blumetro | Sep 10 2014, 09:50 AM Post #7 |
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jack of all trades, master of two
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many years ago I wrecked a perfect turbo cyl head by being over zealous and removing to much material. I hit a oil return passage. tried to fix it with jb weld, that did not hold. now that I think about it, I could have tapped the hole and threaded a long bolt with threadlocker on it, seal up the oil return hole permanently. not to sure if that would have worked, and unfortunately I don't have that cyl head anymore to test my theory on...... |
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| Coche Blanco | Sep 10 2014, 09:52 AM Post #8 |
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Troll Certified
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You could say that you should....respect your elders... |
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| ZXTjato | Sep 10 2014, 10:06 AM Post #9 |
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bass heads
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3 tec did the porting on my head and I have been happy with it. Has a little bit deeper "intake roar" sound, makes it sound like it's trying so hard. At the end of the day tho it's still a metro
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| Old Man | Sep 10 2014, 10:28 AM Post #10 |
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"Still a Metro" That's good tho. Much better than at the end of the day being 'That Damn Metro'
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| Murf 59 | Sep 10 2014, 10:52 AM Post #11 |
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Porting can be a really good thing for your cars head. But a bad porting job can send you in the wrong direction. Get a head or manifold you don't care about and practice. And it takes patience to do it well. Don't try to hog it out all at once. Small little passes. |
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| j63812f | Sep 10 2014, 12:42 PM Post #12 |
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J R
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What exactly do you want to accomplish? Are you turning it into a racecar? |
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| Justahoby | Sep 10 2014, 12:47 PM Post #13 |
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Unqualified informant
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My thoughts kinda also. The mk2 has the iest exhaust port design on the planetI have ported many heads, but never a Metro head |
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| Freeman | Sep 10 2014, 12:48 PM Post #14 |
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The Family Man
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Is this serious? I Googled to get some ideas aside from LeMons racing. Mid 19's is the best I saw out of a 3 cylinder 1.0L Metro. I suppose that was stock, but I can't imagine there would be much of a chance of turning it into a race car. |
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| crankcase | Sep 11 2014, 09:48 AM Post #15 |
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I was thinking of extra MPG, but extra performance is only an added bonus. I like the economy angle to cars (without getting too extreme). Also, porting and other "Little Deuce Coupe" mods are just intresting and appealing from the history and progression of automobile perspective. |
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Exactly what I did. My cast turbo manifold had some obvious 'issues' that could be fixed relatively easily. Same could be said about the exhaust side of the turbo. Other than that, you should take the advice given by those wiser than me. You don't want to ruin anything.
That's good tho. Much better than at the end of the day being 'That Damn Metro'
iest exhaust port design on the planet
9:25 AM Jul 11