Polishing intake manifold

[1994Vib.RedGT]

I want to buy a used Cobra Intake manifold, and I would like to polish it because I know that porting it would be too much for the stock heads, so my question is, Is polishing it something that can be done easily at home, or do i need a shop to do that, and how much would that run for the upper and lower?

 

[SuperDust22]

You can do it your self. It is really easy just takes a lot of time. I have just started porting and polishing my stock 5.0 manifold. After that I am going to port and polish my cobra intake and port some heads to match. All you need it a little hand held grinder and a port and polish kit. I bought mine for $39. They have better and cheaper ones from summit.

Dustin

 

[TrevorB123]

Where do you find out how to do it?

 

[donjohn]

that's a good question, (the polishing kit probably comes with instructions) but on the porting- how do you port the upper.. because i know tmoss said that he just lines up a gasket with the lower. is it the same for the plenum?

 

[SuperDust22]

All the polishing kit is, is a bunch of sand paper rolled up in different ways. You just put them in a grinder or drill of some kind and start grinding on the manifold. It takes all the little bumps off. As for porting I got a tool from work. The ones in the kit sucked and I bought some gaskets and outlined what I needed to take out. I will do the same with the upper. I will try to post pics later.

Dustin

 

[94GTLaserRC]

I would NOT recommend your FIRST polishing project be your intake. You may end up putting deep scratches in there that are hard to remove...PLUS, you will get frustrated REALLY quickly..

Either have someone else polish it or practice on other stuff first.

Also, if you have a chance to port it, go for it...DOnt worry that you have stock heads...You'll be ready to grow with it later..

BTW..The polished Cobras loook REALLY nice.
RC

 

[mo_dingo]

I would NOT recommend your FIRST polishing project be your intake. You may end up putting deep scratches in there that are hard to remove...PLUS, you will get frustrated REALLY quickly..

Also, if you have a chance to port it, go for it...DOnt worry that you have stock heads...You'll be ready to grow with it later..

I agree with this 100%. The first time I worked with gold was on a customers ring (making ring size smaller). Making the taper perfect & making the solder joint disappear was really tough. Once you cut too much material off, you are screwed.

But afterwards I worked with silver, and since it was cheap, I could screw up and not feel like I was an idiot.

Start with something that is flat, and big. Like a piece of metal in the shape of a 2x4 piece of wood. That way you can practice in one section, then move on. It's really easy to slip with a grinder. And if you do, it's really difficult and time consuming to fix. When you feel comfortable with it, try something with complex curves. This will prepare you for the intake manifold.

But don't let this intimidate you. This is just to prepare you. Do it yourself, and feel proud of it every time you open the hood of your car.
Scott

 

[94TURBO5 O]

I think he's talking about polishing the inside.

 

[TrevorB123]

i believe so

 

[94GTLaserRC]

I think he's talking about polishing the inside.

No sense in wasting time polishing the inside of an uported intake...
With your mods currently, that Cobra will flow plenty.

I had a chance a couple years ago to buy an extrude-hone Cobra with a mirror finish for $700....It came off a car making 500+ RWHP...

RC

 

[tmoss]

Save your stab at porting the intake for later when you need it, the stock intake is more than enough for stock heads. No sense loosing more torque now.