Super Dirty Intake Mani.

[VerbalKint]

91 FWD 2.0 NT Talon 5spd.

Ok.. Pulling head, transmission, etc etc for a complete breakdown, workover,and rebuild (cause I have the time to, thats why)

Just got the intake mani off, and the thing has about 1/16 inch of 'sluged' in it. Just dirty, wet, gas soaked carbon buildup.

My MAIN question is... Worth it to get it cleaned up, and ported to match the head (which is going to be ported, polished, etc etc), or just get an aftermarket intake?

Secondary, what would cause THAT much carbon build up? I'll post a pic soon as I dig my digi cam out of my wife's caviler.

Thanks,


Dave

(edit) and due to, in part, my ignorance, could this post be moved to troubleshooting, where it most likely belongs?(/edit)

 

[97TSIAWD]

91 FWD 2.0 NT Talon 5spd.

Ok.. Pulling head, transmission, etc etc for a complete breakdown, workover,and rebuild (cause I have the time to, thats why)

Just got the intake mani off, and the thing has about 1/16 inch of 'sluged' in it. Just dirty, wet, gas soaked carbon buildup.

My MAIN question is... Worth it to get it cleaned up, and ported to match the head (which is going to be ported, polished, etc etc), or just get an aftermarket intake?

Secondary, what would cause THAT much carbon build up? I'll post a pic soon as I dig my digi cam out of my wife's caviler.

Thanks,


Dave

I'm not sure if this is it, or if the n/t have them but maybe the EGR? Not really sure though. Also, I don't think it would be much money to clean it and port match it, at least not as much as an aftermarket IM. If you want to go that route a SMIM is a great upgrade, but if your looking to save some money, you could have the old one cleaned and ported easily enough.

 

[VerbalKint]

Here's a quick shot of the intake.

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[spyderman]

Sounds like you have some heavy miles on that engine. Carbon and oil build up in the intake is usually a result of blow-by caused from worn piston rings and valve seals, getting drawn back through the intake through the EGR and PCV Valve. You can do a relatively low cost rebuild by changing the basics such as rings, bearings seals and gaskets. Thouroughly clean all of the parts and the port work is realatively easy to do with a die grinder. Use a new gasket as your template and place it on the gasket surface of the intake. Align the bolt holes and then trace the gasket opening onto the intake manifold. Useing a die grinder, remove the excess material until you have reached your trace mark. Try to avoid leaving any sharp edges or abrubt changes. The object is to improve the flow not create other problems. Using a grinding stone in the die grinder, go back over everything to remove all rough edges. It is not worth the effort to 'polish' the manifold as there is no benifit with a dry manifold setup. Repeat the process on the exhaust manifold as well. You can also do this to the head but be sure the head is off of the engine and you must use extra caution not to hit the valves or valve stems with the die grinder. Clean the living crap out of everthing with a mild solvent and compressed air to remove all traces of grinding dust and debris. When reassembling the engine, take your time, use new gaskets and sealers. Always use a torque wrench and don't force anything! If it is not going in smothly, you are probably putting it in wrong.

When all else fails, ask questions.

 

[VerbalKint]

Thanks for the replies... I am not 100% sure I am up to doing a port job by myself... I'd need something like a Yugo to practice on.

I'll have to THINK about that, but I am willing to pay polk performance to do the Port / Polish


As for miles, yeah, 110k Miles. Getting up there.

I'll have the head off tomorrow, so I'll know then what the cylinders look like. ;-/

Scary stuff...

 

[spyderman]

Glad to help. And just so you understand the benifits and downsides of polishing, let me tell you what it is and does. Back in the day when cars had carburators, racers were looking for ways to increase horsepower as always. A stock intake manifold and head ports have a slightly rough surface. This is for a reason, the rough surface helps to break up the droplets of fuel and mix with the air better before reaching the combustion chamber. This is a process known as atomization. By polishing the intake and head ports it eliminates the roughness which reduces the atomization affect and creates a richer fuel mixture. The benifit to the racer is the richer mixture helps to cool the combustion chamber allowing him to run a higher compression ratio without fear of detonation. This only works with a wet manifold. A wet manifold is a manifold where both the air and fuel pass through the manifold such as a carburated engine or one with a throttle body injector. Most cars today, including all DSM's, use a dry manifold setup. Only air passes through the intake as the fuel is injected directly into the intake ports of the head, hence the name Port Injection. There is also a difference between cleaning up the rough edges and polishing. A true polish job leaves the surfaces with almost a mirror finish. There is real no benefit to a true polish job on a dry manifold engine. Hope this helps.