Polished Intake Manifold - what are they worth?

[GTSjbud]

There is a Gen. II polished intake manifold for sale on Ebay. Any idea what a fair price would be for this? eBay Motors: Polished Dodge Viper Intake Manifold BEAUTIFUL (item 150184999198 end time Nov-25-07 16:49:47 PST)

Thanks in advance for the input!

Cheers
Jason

 

[MTGTS]

no idea what it's worth but it sure does look nice

 

[v10kingsnake]

cleaning that thing would be tons of fun. NOT

 

[jpa99acr]

what is the stock intake manifold worth, reg unpolished? that would help answer the original question. I have no idea but I know some of those here does. Also would it be an easy switch or would you need the fuel injectors too?

 

[SilverSnake]

The other problem with a polished manifold is that the injector sometimes have a problem sealing .I Know of two cars that it happened too.

Also polishing will hold the heat longer than a non-polished manifold.

 

[KenH]

I have seen them sell for around $1000 in the past. I would consider anything under about $800 a good deal. I have also heard about issues with injector seating on some polished manifolds.

 

[GTSjbud]

Hey guys...thanks for the excellent info! I think I will sit and wait to see what happens with the bidding.

Cheers
Jason

 

[dave6666]

Blinded by the light...

Does it come with lunar tint goggles?

 

[GTSjbud]

Blinded by the light...

Does it come with lunar tint goggles?

Yuka yuka yuka

 

[1TONY1]

I have seen stock intakes not sell for $500.....or at least it took a while.

 

[Joseph Dell]

I usually see intakes go for 300-ish. and i have a local powdercoater who did my valve covers for $50 for the pair and $150 for the intake. millerpowdercoating.com/Powder coating almost any metal part, Serving Atlanta for ten years. great guys (Bill is the owner and Billy, his son, does excellent work).

Better off w/ that option IMHO.

JD

 

[KenH]

I have seen stock intakes not sell for $500.....or at least it took a while.

But not polished ones. There must be at least $500 in the polishing labor I would think.

 

[1TONY1]

what is the stock intake manifold worth, reg unpolished? that would help answer the original question. I have no idea but I know some of those here does. Also would it be an easy switch or would you need the fuel injectors too?

But not polished ones. There must be at least $500 in the polishing labor I would think.

Agreed, I was answering jpa's question....I should have quoted him.

 

[AZTVR]

Also polishing will hold the heat longer than a non-polished manifold.

That's an interesting effect that would not have occurred to me. I would have thought that the powder coating would have acted a little like insulation. Even if you were referring to a bare casting. I'd have guessed that there wouldn't be much difference in heat radiation. Perhaps it is the same effect like black things radiate better than white ?

 

[Jerome Sparich]

Also polishing will hold the heat longer than a non-polished manifold.

I'll bite

Explain how please???

 

[Hisserman]

Aren't the intakes made of magnesium like the valve covers. If so, they have to clear coat the polish to keep it shiny -- or the heat will turn it dull like the lettering on the valve covers. Otherwise wouldn't this thing be hard to keep shined if it was on the engine and absorbing engine heat?

 

[carguy07]

Aren't the intakes made of magnesium like the valve covers. If so, they have to clear coat the polish to keep it shiny -- or the heat will turn it dull like the lettering on the valve covers. Otherwise wouldn't this thing be hard to keep shined if it was on the engine and absorbing engine heat?

Intake is aluminum.

 

[Batboy]

Wow! That is a great price! But the first bid is probably not the reserve. So, who knows what the reserve is. I have considered doing this to mine for a while, but the only place I know of is a vendor that advertises here. I forget the name and don't feel like researching it, but they want $1000 and your old manifold. So, a completely second one already chromed for $300 is unbelieveable. But again, that's probably not the reserve. Good luck bidding as I unfortunately don't have some extra cash to buy it myself.

 

[dave6666]

I'll bite

Explain how please???

Reduces surface area on a micro level.

 

[Jerome Sparich]

Reduces surface area on a micro level.

Why don't I buy this for a second? Try again maybe?

How about me saying that the shiny surface reflects heat waves? (Taken from an ad for "heat reflective tape" available at Lowes and Home Depot)

I see what you are trying to say, but that little will make zero difference.

Any metallurgist here? I would love to hear their answer.

 

[dave6666]

Why don't you buy it for a second? I'm not your mother pal.

Emissivity Coefficients of some common Materials

Heat - Heat Transfer

 

[Jerome Sparich]

Why don't you buy it for a second? I'm not your mother pal.

Emissivity Coefficients of some common Materials

Heat - Heat Transfer

*** does you not being my mother have anything to do with this???

I asked a question, you answered, I said in polite words, BS.

Now the Pal part, I doubt that also, seeing how you are copping an attitude.

So be it, no worries on may part.

I don't have the patience to search through the Mr. Wizard links you posted, care to show me some proof as in direct links or real world facts?

Also, howitworks.com doesn't count as facts.

Thanks

 

[dave6666]

Apparently you want a cereal box type explanation.

Sorry, metallurgy is more complicated than Captain Krunch tech articles.

I think you are just too lazy or stupid to figure out the reference material I sent links to.

It is not hidden Mr. Wizard stuff.

 

[Jerome Sparich]

Apparently you want a cereal box type explanation.

Sorry, metallurgy is more complicated than Captain Krunch tech articles.

I think you are just too lazy or stupid to figure out the reference material I sent links to.

It is not hidden Mr. Wizard stuff.

Stupid? Why yes I am.
ASE Cert Master Tech.
Did my studying in metallurgy while apprenticing for 4 years in a machine shop, and currently hold a job that won't put Pro Line out of business, I would be an asset to such a company as them.

So I guess stupid ole me will just sit back and watch you have a breakdown, for what reason I am not sure. I guess asking a simple question is beneath you to answer?
So why did you even bother wasting a combined what, 3 mins maybe, to reply as much as you did?

Next you will ask if I own a Viper....won't you? Like that makes any difference in things.

I will leave the last reply to you, and it seems that I am not worthy of a decent reply, or even the slightest bit of respect.

 

[dave6666]

From Encarta... MSN's on-line cereal-box encyclopedia.

Generally, dull, rough surfaces absorb more heat than bright, polished surfaces, and bright surfaces reflect more radiant energy than dull surfaces. In addition, good absorbers are also good emitters; good reflectors, or poor absorbers, are poor emitters. Thus, cooking utensils generally have dull bottoms for good absorption and polished sides for minimum emission to maximize the net heat transfer into the contents of the ***.

Look it up yourself there.

It's called heat transfer.

 

[dave6666]

Next you will ask if I own a Viper....won't you? Like that makes any difference in things.

I could care less if you own a Viper, as heat transfer and metallurgy have nothing to do with whether or not you own a Viper.

There.

I have spoken last.

Again.

 

[big-n-italian]

it took alot of work to get that intake to that point. very pretty.

 

[GTSjbud]

No bids as of yet.

 

[Tom F&L GoR]

BZZZT! Reality check.

Radiation heat transfer q= (emissivity)(Stephan Boltzman constant)(T of hot item^4 minus T of cold item^4)(area)

The constant is 5.67E-8, so if you assume a 100C difference between the hot intake and the cold surroundings (and I think that is greatly exaggerated) and that the area is 1 meter^2, then q = around 80 W, depending on whether you pick polished or not.

Convective heat transfer (wind) q= (convective heat transfer coefficient)(area)(T of hot item - T of cold item cold)

The convective heat transfer coefficient of air is between 10 and 100. Take the same difference in temperatures and the same area, and the q = 10,000 W.

Note that my exaggerated temperature difference favors radiation, since it uses temperatures to the 4th power. Even so, the radiation heat transfer amount is 1% of the convective. Plus, we are talking about an engine part that is barely connected to the engine (not like carburetted manifolds were) and is probably gaining heat from radiation of the hot engine underneath it. In that case, a polished surface probably keeps it cooler.

All the formulae and constants are in the link provided earlier (engineeringtoolbox.com.) Unless there is a lab rat in your chemical plant that has some data, I think that for all practical purposes, a polished intake won't change power output.

 

[dave6666]

BZZZT! Reality check.

...polished intake won't change power output.

I agree that the polished intake won't change power output. For what that is worth.

But I believe it will change the amount of heat it holds. Whether minuscule or not.

With my background in air cooled engines, you do nothing that would possibly insulate or have negative effects on heat xfer coefficients. But they are carbureted, and like you said, not much connected to the FI intake.

Anyway, temp up or down of the intake was the question. I think we've killed this one!

Thanks Tom.