Ported and polished?

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MAJ28
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Ported and polished?

Postby MAJ28 » Tue Apr 02, 2002 12:48 pm

I've been hearing the phrase "ported and polished" for the longest time now.  What does it mean?  I'm not understanding?  Also how do i get off the intake manifolds?  What do they look like on a 3.1?  Is it a problem if I take them off?  Or can I remove and replace on a whim?  Can I do this porting and polishing myself?  What kind of HP gains can this produce?  

Jason

P.S.  Just one more of those things I haven't learned about yet...  i'm getting to know what I'm doing thanks to bnet...


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Canada
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Ported and polished?

Postby Canada » Tue Apr 02, 2002 1:16 pm

Porting and Polish removes metal inside of the manifolds to allow it to flow easier, allowing more air to enter the engine gets you more power. The intake manifold is on top of the engine. Your TB and intake is bolted to it. It is the part that says 3.1 L on it. The upper one is fairly easy to do. The lower one is hard. A ported upper manifold, on my 3100, is supposed to make an 8 hp gain. Lower 10 hp gain. This is something you could do yourself, with a dremel and a lot of time. But it would only be port as far as you could reach in. One that you would purchase would be ported all the way through. They use a gel type stuff to squeeze into the manifolds and it eats away at the metal. A ported manifold would be a good upgrade after a different intake and throttle body. This just lets the engine breath more. Ported exhaust manifolds or headers would be the next step.



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Ported and polished?

Postby Guest » Tue Apr 02, 2002 5:17 pm

Not all places you go to to have them ported will be all the way through. The only place I know of to get it all the way through is extrudedhoned.

Porting= making the "ports" bigger/larger thus flowing more air by removing metal.
Polishing= smoothing the metal up and removing rough spots or chunks of cast to make it smoother and less turbulance for the air.



Guest

Ported and polished?

Postby Guest » Wed Apr 03, 2002 12:21 am

So you are saying about an 18hp gain when you port an polish the upper and lower intake manifolds. That sounds like a pretty nice gain in power would this be about the same increase for my 2.8L? :)



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MAJ28
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Ported and polished?

Postby MAJ28 » Wed Apr 03, 2002 2:24 pm

so combining that with a bigger TB would give me about 25 HP?

What about the exhaust manifolds?
Do these things just unbolt, then bolt back on?
No gaskets or anything I have to buy?
I can just unbolt, dremel, and rebolt?
How much $$$ if I buy one?

Maybe I could buy just the upper manifold at a junkyard, then I can have the car running while I port it...  hmmm

Jason

Would I still see similar gains, even if I couldn't afford a bigger TB?  And used stock airbox?  Could someone post a picture of the TB... I think I know what part you mean, but I'm not sure...


> > > > >    1995 Z26 with 82k    < < < < <
> > > > >      LG8 3100  ÃƒÆ’ƒÆ’ƒâ€šÃ‚   < < < < <
~~~~~~~~Cleaned Up sig courtesy of Engray M~~~~~~~~


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MAJ28
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Ported and polished?

Postby MAJ28 » Wed Apr 03, 2002 4:09 pm

Would any of these work:

------------------------------------------------------
14044991  Intake Manifold     ÂÂÂ
This two-barrel aluminum intake manifold is used on rear-wheel-drive V6/60º Chevrolets.   ÂÂÂ
Technical Notes: Manifold can be modified to mount a two-barrel Holley carburetor for off-highway applications. ÂÂÂ

--------------------------------------------------------------------------------

    ÂÂÂ
24508393  Intake Manifold "Lower"     ÂÂÂ
This high flow intake manifold is used on late Gen III design model V6/60º engines. This manifold matches to port locations of the Gen III head with revised fuel injection locations for improved targeting on the intake valve.   ÂÂÂ
Technical Notes: Must be used with new cylinder head P/N 10218167 and upper manifold P/N 24508396. ÂÂÂ

--------------------------------------------------------------------------------

    ÂÂÂ
24508396  Intake Manifold "Upper"     ÂÂÂ
This high flow intake manifold is used on late Gen III design model V6/60º engines. This manifold is the upper half of manifold P/N 24508393.   ÂÂÂ
Technical Notes: Must be used with new cylinder head P/N 10218167. ÂÂÂ


So what do you think?  The '90 model are what Gen?  I'd guess Gen II...



Nevermind new cyclinder heads are expensive.... arggggg...


> > > > >    1995 Z26 with 82k    < < < < <
> > > > >      LG8 3100  ÃƒÆ’ƒÆ’ƒâ€šÃ‚   < < < < <
~~~~~~~~Cleaned Up sig courtesy of Engray M~~~~~~~~


Guest

Ported and polished?

Postby Guest » Wed Apr 03, 2002 7:41 pm

GEN III is 3100/3400. You have a pre-94 right? Then yours are GEN II.

You will probably get ~20hp with P&P uppper/lower/TB, only if you have a better than stock exhaust and intake. Other wise that will reduce the effects you can gain from the P&P. I'm guessing here.

As far as the exhaust manifold, there is gaskets for that. You can port them yourself like McGavinZ26 did. Check his website for info on that. And check your down pipe it may be really small and restictive.



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Ported and polished?

Postby Canada » Wed Apr 03, 2002 8:18 pm

Also, 2.25" exhaust piping, high flow muffler, maybe even a high flow cat.



-2007 Saturn Sky Redline
-2007 Chevrolet Silverado Classic 2500HD
-2006 Chevrolet Impala SS
-1996 Chevrolet Camaro Z28
-1996 Chevrolet Beretta

Guest

Ported and polished?

Postby Guest » Wed Apr 03, 2002 9:55 pm

Quote (Canada @ April 02 2002,1:16)
The intake manifold is on top of the engine. Your TB and intake is bolted to it. It is the part that says 3.1 L on it. The upper one is fairly easy to do. The lower one is hard.

So what you're describing as the "upper" intake is the same as the Plenum, right?



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Ported and polished?

Postby Canada » Wed Apr 03, 2002 9:59 pm

The plenum is both upper and lower. After some more research, it sounds like if you swap the upper, you'll have just as much work as you would replaceing the lower. So go with both. Mantapart has both the cheapest $300, SSP Engineering $325, and Street Arsenal was way higher. Sounds like they're all the same.



-2007 Saturn Sky Redline
-2007 Chevrolet Silverado Classic 2500HD
-2006 Chevrolet Impala SS
-1996 Chevrolet Camaro Z28
-1996 Chevrolet Beretta

Guest

Ported and polished?

Postby Guest » Thu Apr 04, 2002 12:47 pm

I don't know how hard it would be to remove just the upper on the old MPFI engines though.

The 3100 you might as well do the whole thing upper and lower.

The mpfi 3.1 should be easier as I recall there is less stuff on top/around the upper plenum...



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Ported and polished?

Postby NVMYGTZ » Thu Apr 04, 2002 12:47 pm

One thing to remember about Modification HP numbers is that they do not add up like:
5HP cone filter
20HP Cams
10 HP Exhaust manifold
These will not equal 35 HP in the end.

Each modification removes/reduces a restriction in your air pump (That’s what a motor is)
Each one is a percentage, and relies on how the rest of the system flows.


Adam
93 GTZ Q4<-- Just a few mods =^P
92 GTZ Q4<-- A few less than above
91 GTZ Q4<-- Euro-spec *Black*
69 Chevelle 396SS


http://www.nvmygtz.com/

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Ported and polished?

Postby 89GTZ » Thu Apr 04, 2002 3:16 pm

It's not too hard to take off the intake and plenum, trust me, if I can do it anyone can.   :)   Just make sure you know where everything goes when you put it back on.  


89GT(Z)
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Canada
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Ported and polished?

Postby Canada » Thu Apr 04, 2002 7:46 pm

I don't know the motors for the older ones, but is that a 2.8 or a 3.1?



-2007 Saturn Sky Redline
-2007 Chevrolet Silverado Classic 2500HD
-2006 Chevrolet Impala SS
-1996 Chevrolet Camaro Z28
-1996 Chevrolet Beretta

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Ported and polished?

Postby 89GTZ » Thu Apr 04, 2002 8:03 pm

87-89 is a 2.8.  90-93 is a 3.1


89GT(Z)
15.904@85.15 - many years ago


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