Plenty of guys on here running not wrapped or coated ....without any problems at all ......I think this is being way over thought ......
Dave

 

Literally almost everyone runs them not wrapped and not coated without issues.

 

Coating is ok,but wrapped headers look like ****...I've only seen wrap on Rat Rods.

 

May i ask where is all of the oil coming from that will get on the headers?....I've had headers on many cars and never had a problem with oil on the headers.

 

I have heard of oil filters popping at high pressures, oil filter gaskets failing, oil lines/brake lines/power steering lines failing, etc.
Still, these would probably all cause a fire whether the wrap was on there or not so idk if its really a header wrap con.

 

I dont really care about looks under the hood as long as it performs well. I actually think a well done wrap looks great... and I'm more anti-chrome than anti wrap.

 

Possibly. But if you could improve performance by lowering under hood temps, increasing velocity scavenging with possibly minimal cons, why wouldnt you?

 

You are wayyyyy over thinking this dude .....please tell me you are joking with everyone here ...

the gains that you think you are going to get by increased scavaging...? Really ... show me the data on what the gains are ....
I have been around a long time and never has increasing the velocity of exhaust gas by wrapping headers ever shown to produce gains ...

Other modifications such as the design of the collector etc will increase the cylinder scavaging....but not wrapping or coating coating the headers ....

Also please show me the data on lowering in temps... I am dieing to see this information

And please ..Not someone feels like the temps are reduced ... show me real data

You are not running a pro stocker or a road race car ... by God you are running a street car , how much heat you think you are going to produce ...

I did measure the temps around my starter at several points and with uncoated headers the temps were actually lower ....
that cast stock iron manifold with a hot cat radiating much more heat than my stainless steel LG's do .....

Just use common sense , wire tie the clutch hose and any wires so they stay safely away ,heck u dont even need the spark plug socks if you take your time and angle the wires correctly

You do what you have to do...but I am telling you u are wasting your time ..
Dave

 

RIGHT..and a lot make way more power . but this guy feels the need lol

Dave

 

The first thing you should do is to add a CAI to lower the IAT's.

 

From thermodyanic point of view, the heat is useful only as long as it is contained within the exhaust system. So you are correct to both coat and wrap the exhaust along any length. This will also help reduce underhood temperature which will help IAT as well.

Remember that insulating materials work both ways. i.e. if you insulate the starter, you both reduce the heat transfer rate into it, as well as reduce the heat transfer out of it. think of an oven; if you shut the oven off, it stays hot longer with the door shut.

 

Thermodynamics. I will guarantee you that the headers will get the under hood materials hotter. Headers WILL be hotter than cast manifold at the surface, and radiation is a function of surface temperature.

I am NOT joking. I was simply asking anyone who has installed their own set of headers what wires and materials were near it.

I understand (as I CONSTANTLY mentioned) that header wrap COULD hurt the headers themselves. I did look up 304SS's acceptable intermittent temperature (which is 1600F, continuous @ 2000F) and I believe its within tolerance of most NON-FI EGTs. I also mentioned I would measure when I did wrap it.

If the headers are higher than 1600F then I planned on unwrapping them because -surprise- I am not an idiot.

Just FYI, common sense is not very common. If you can show me that wrapping headers IS a problem, in any other respect than what I mentioned please let me know instead of just parroting other posters.

It will cost me $60 of header wrap and maybe 2-3 hours of my time to wrap. Maybe another $50 in wire loom wrap and $25 for a starter blanket.

So for less than $150, if I have lowered under hood heat and (look this up if you dont believe me) electronics and plastic damage due to said heat, it is worth it.

As for why it will heat up more with headers?

EGT (same temp regardless, assuming same power/performance level) -thin stainless tube->outside air

EGT - THICK stock manifold -> outside air

Simple convection -> conduction ->radiation experiment.

Even if the convection is the same for mani or headers, the thickness of a stock header manifold appears to be 1/4" to 3/8" compared to a 16 or 18 gauge header pipe thickness. What do you think will be hotter to the touch?

headers-WILL-create a hotter underhood temp. However, manifolds will remain hot longer due to their thermal mass.

Why your starter was hotter with stock manifolds, I have no idea. Possibly, the cat is radiating far more heat than the headers at the time. If you were to drive it hard and measure temps immediately I suspect a very different scenario. I believe a cat's operating temperature is (from google searching) 400 to 1200F so if your cats were on the way out, it could definitely have been radiating much more heat. They are also designed to heat up quickly so if you drove the car for both measurements for too short of a period, the cats would be fully heated up while the headers would not...

 

Yup, done.

Well - sort of. Its the GS model so I have the small NACA-esque duct that allows cold air into the airbox location. Not quite as large as a vararam or vettescoop but similar in result. I have the entire air box insulated and I am looking to make something similar to the halltech beehive to hide the filter from under hood air. I would prefer to swap intakes for a larger bridge but I do like the OEM filtration. Still, I think the larger bridge is mainly unnecessary for me since the Z06 with much more HP uses the same intake size.

I had a K&N on my previous vehicle and that rotted out the cotton filter media so if I did go to a true CAI, I would go with the MAF forward halltech with some dry flow filter. Not sure why GM put the MAF/AIT right on top of the radiator. I actually monitor my IATs constantly (Dashcommand!). As long as I am +45 mph, my IATs are +5F of ambient or less. When it heat soaks while sitting at a light, it takes roughly 1 min before the IATs drop. Not TOO bad. Im definitely looking at how to insulate my MAF/IAT from the radiator as well.

Am I looking for 1K HP? Not currently. I just want my car to be extremely well maintained. I have way too much experience with old GM cars (4th gen camaro, 3rd gen formula firebird, 3rd gen camaro, etc...) and know how CRAP the plastics they use are to put too much trust in it.

 

Thats true. now thats something I haven't given much thought about. I guess I need to see the temps the headers reach to decide if it makes more sense to allow the starter to radiate/convect heat outwards vs taking in header heat...

I plan on leaving a small section of the header primary entry exposed so i can take temps of the hottest location. I think that would also be a good physical break for oil which may leak from the valve cover which I am most worried about. Header failure is not a huge concern because if it fails, ill just go back to stock...

 

Lol and I thought I over think things ...

 

My BB header instructions say nothing about shielding the starter only the clutch reservoir line and I have an A4. Kooks, ARH, Billy Boat, etc have so much historical data that I trust the instructions given.

 

What I am getting at is, if the component in question is sensitive to heat, but is in a location where max temp exceeds desirable input, insulation is only going to slow down the eventual over-heating, and prolong it's stay. In this case you will want to shield, reflect the radiating heat instead of slowing it down, which should reduce the eventual max temp it can achieve. Then, on the object (in this case, a starter) you might consider additional heat transfer materials if necessary, for example if you wrapped a bit of copper or aluminum wire around the starter and led i out of the car where it could act as a "heat sink" to the air around the car. Not suggesting you do this but I've seen similar treatments to airplane components which gave me the idea.

 

I've seen that done on some of the newer high power LEDs too. I suspect that in this case it wont be a fully insulated situation since heat can pass through the starter itself to the mounting location. I'll also insulate only where the header/starter are in view of each other just to cut radiant heat while allowing convective transfer.

 

Bumping this up with some information for those who want to heat shield everything:

I purchased an IR thermometer to check temp difference between manis and headers. On a normal drive, the outside of my manifolds would be about 200C. With these WRAPPED headers, its now about 500C. So for everyone stating "its no different" - theres a HUGE difference. The plastic pieces around the engine bay which used to be cool enough to touch are now way too hot to touch after a drive.

On to the important stuff:

I wrapped: Starter, AC lines, clutch line, oil cooler lines and o2 lines. thats it!

 

I did the same test and it depends on where did you measure the manifolds . I took my heat shields off and measured the cast iron and the cast iron was wayyyyyyyy hotter and retained the heat way longer than the stainless tube

Also are you sure it was 500c u measured , that 900 F hmmmmmm that's pretty hot