Exhaust Wrap?????

Sinbad

Sinbad

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For the sake of not having to go through god knows how many threads to find the answer I'm going to go head and start a new one... As the title says Exhaust Wraps. Does anyone else here use them because I've heard a lot of contradicting advise on the subject. I would like to use it but don't want to risk damage to my headers being as I just got them and all. I bought them used from another member here and they do have some damage on the ceramic coating, minor but its there and I would like to preserve the heat resistant's without having to send them to be recoated <<<<(Yes I know this is the right answer). I've already purchased the wrap and am now not sure wither or not to use it :banghead::dontknow::banghead::dontknow:

thanks
 
I wouldn't, unless there is a chance of a real hot spot near a harness or spark plug wire, etc.
 
Turn your headers upside down so they come out through the hood and then install flame throwers, I mean, thats what I would do..
 
I believe the header's job is to release heat asap to help draw the next charge into the chamber during overlap. I would focus on shielding the items that will be affected by the heat and leave the headers alone. repair the coating would be best.
 
At the risk of sounding ignorant...

I'm pretty sure the exhaust scavenging effect is caused purely by maintaining exhaust velocity (with maybe a slight input from pulse timing to create back pressure at just the correct time).

Letting the headers cool, to try to induce some sort of gas compression in the header to pull a vacuum on the combustion chamber, would be negligible compared to the effect on exhaust gasses by proper velocity tuning...

Jeremy
 
Plus the added intake manifold heat soak due to heat transfer from the headers to the engine compartment would reduce intake charge density and actually reduce volumetric efficiency.
 
Nucdancer01 said:
Plus the added intake manifold heat soak due to heat transfer from the headers to the engine compartment would reduce intake charge density and actually reduce volumetric efficiency.
Click to expand...

This could be some interesting discussion... I believe that after the exhaust valve opens , pressure is released into the header tube and instantly equalizes. As the piston completes it's stoke up,the gases in the tube will collapse as the tube gives up it's heat which inturn will pull cool intake air into the chamber during overlap. the tube is to long and collector to far for any cross contamination. . the coolant around the combustion chamber will also help to shrink the chamber gases all this heat loss creates a vacuum that is capitolised during overlap. . The only way to contaminate the combustion chamber and/or intake manifold is if the engine is turbocharged and the exhaust pressure exceeds intake pressure. Say if ,during spoolup of a turbo , the exhaust pressure is higher than the intake charge pressure. food for thought ....:rock::D 1 more thing.... air volume in is equal to air volume out at the same temperature. the only thing we do is add fuel and spark which expands what is there. nothing extra except HEAT and EXPANSION.
 
Ideal gas law states that a pressure of a gas is distributed evenly against all walls of its vessel, undiminished. Therefore volume of a gas takes on the proportions of its container. Volume in doesn't equal volume out...

That's the entire premise behind volumetric efficiency.

Plus, you can't discount the increased gaseous inventory in the exhaust because of the hydrocarbons produced during the combustion process.

Pressure of the exhaust gasses does not equalize instantly. You have to break down time to study a near instantaneous event. The gas acts just like a high pressure liquid on a molecular level... There will be roughly three distinct phases of pressure: the leading edge, the main body, and the trailing edge (or tail). The momentum of the gas as it travels through the exhaust system will tend to pull the tail out of the cylinder.

During overlap with the absence of forced induction, the exhaust-ing action pulls the intake charge into the combustion chamber. This process is aided by the low pressure (relative) created when the piston is in the intake stroke.

Once again, I don't know these things. They are purely hypothetical as I've never gone to college, or obtained an engineering degree. I'm just trying to put together some related things I've learned along the way.
 
Sorry...

That's pascals law, not the ideal gas law.

And it refers to pressure of a fluid, not gas. My bad! Been out of school too long.
 
Well dude if youve never gone to college and you dont know anything about this stuff you sure as HELL sound like you do...
 
I dropped out of high school after grade 10. Not one of my smartest moves but I challenge someone to discredit my logic. It is all I offer. For discussions sake. I seek to learn.
 
Thank you Venom. I appreciate your comment.

I spent 15 years as a Navy Nuke, electronics technician. Oh, and I did teach nuclear reactor theory for a few years..

There was a lot of physics, materials, heat transfer, fluid flow, radiological fundamentals, chemistry, yada yada yada along the way.
 
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Nucdancer01 said:
Thank you Venom. I appreciate your comment.

I spent 15 years as a Navy Nuke, electronics technician. Oh, and I did teach nuclear reactor theory for a few years..

There was a lot of physics, materials, heat transfer, fluid flow, radiological fundamentals, chemistry, yada yada yada along the way.
Click to expand...

I thought so, your name was a dead giveaway. Anyhow, I like having smart friends. Feel free to come over and bang my sister while I go online and take credit for all of your accomplishments. just kidding. Kindve
 
bottom line, if you think your headers look like crap now, put on the exhaust wrap and then when it starts falling apart in a couple of years and you go to peel it off, it's gonna be worse than where you're at right now. Pony up and get re-coated and be done with it.
 
Yea, dont wrap em. I tell ya man, i really just dont see a problem with the stock headers. When the SRT engineers made this awesome thing happen, Im sure they didnt stop at the exhaust. Im sure that certain regs stopped them. But what you get from the factory is only an example of what the motor COULD be. And they knew that. No need to wrap em bro, no reason at all. In my opinion, no need to re coat them either, they will work the same no mater what you do to them
 
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