View Full Version : Header Temps
The post about stacks got me to thinking ... I know ... dangerous as always....
Used to see stacks on a lot of pickups and they were popular back in the day.
Generally speaking, not too many got burned by them.
The long pipes running alongside the bed clear out to the tailgate - called bellyburners by some - weren't too bad in the burned civilians dept. on the stepsides, but the fleetsides, slab-sides or whatever you want to call the full-width beds ended up burning more than a few at the various drive-in's.
Seems like the owner of a very nice, bright orange supercharged 58 Ford half ton with slab-side would park, somebody would walk by, inadvertently touch them and get burned.
Seemed too, the pipes would stay hot for quite a while.
My experience with black painted headers on my Olds powered 50 Ford coupe and bother-in-laws 61 Dodge with 413 with tube headers and a few others had the headers cooling down pretty quick after shut-down.
Cool enough to change plugs bare handed after maybe ten minutes or so.
Since the belly-burners and stacks were chrome plated, I wonder if that's the reason they stayed hot so long.
And maybe the time factor isn't what I think it is and they all stay hot for about the same length of time.
Big reason I ask this question is, I have some headers set up to adapt to the 455 Buick in the 31 and was thinking chrome, unpolished chrome, nickel or Jet-Hot would remain hot.
My big fear is burning a little kid as they're right down where the headers are.
As the pic below indicates.
Not to mention that adults who look over the highboys get pretty close and I can see them getting burned as well.
Not such a big deal at a rod run where you can hang out with the car until things cool down, but using the car to run errands etc., I can see the unknowing and unthinking getting burned.
The Olds and 413 headers mentioned above were painted flat black with VHT - or similar product - at the time.
Since black is the best heat radiator of all the colors, I'm guessing that is the reason for the rapid heat loss.
Long ways to the question, granted, but what I want to know, do any of you have personal experience with plated or Jet Hot headers?
And if so, does the heat last a long time?
Right now, besides 'looks', the outside headers are appealing simply in terms of construction time.
Even so, I'm not afraid to tackle a set of in-frame headers similar to what I have on the 32.
flt-blk
11-27-2003, 12:31 PM
As I understand the Ceramic coating is an Insulator. Logic
would dictate the heat would stay in them longer than a non-insulated
surface. What that means to the time-to-cool I don't know.
If it helps I not that many people around here look that close, the ones that do can usually feel the heat radiating off the exhaust when you get close. I wouldn't worry too much about it.
TZ
Cword
11-27-2003, 12:55 PM
I honestly can't say that I've ever timed the cool down cycle of headers, but it wouldbe interesting. I've got a data acquisition unit in the garage for 1149 and am looking for ways to play with it, maybe that's one I'll try.
Dad's headers have burned a lot of folks, not so much the header, but the side pipe running under the door of the car. Most recent victim was dad, last weekend at the Santa Claus parade, he melted a hole in his ski pants on the side pipe.
http://www.fsra.org/cdnrodder/22nov5.jpg
The black cool down anecdote you relate is interesting.
There is a property called emmissivity (sp), the ability to emit heat radiation which is higher for black surfaces than most any other colour. It is best demonstrated in a vacuum though because conduction/convection will provide more cooling than emissivity. Emissivity is a minor effect which causes black objects to cool faster than objects of other colours. How much faster is open to testing/debate.
Mike
Cool pic - no pun intended.
The characters riding the back seat as well as your dad being seriously bundled up make his roadster look about 3/4 scale.
I bet your dad never felt a thing with the ski pants insulating him from the heat.
Used to do that one on my Ducati 350 Enduro when standing up on long downhills in the dez.
The lineman boots I wore would be up against the long straight pipe and by the time you realized things were hot it was too late.
Just had to suffer until the leather cooled down.
[ QUOTE ]
The black cool down anecdote you relate is interesting.
There is a property called emmissivity (sp), the ability to emit heat radiation which is higher for black surfaces than most any other colour. It is best demonstrated in a vacuum though because conduction/convection will provide more cooling than emissivity. Emissivity is a minor effect which causes black objects to cool faster than objects of other colours. How much faster is open to testing/debate.
[/ QUOTE ]
One objective test article I read talked about colors, reflectivity, emissivity etc. on sailplane wing panels.
White being the best choice there.
In the subjective fwiw dept., one of the guys in our group ran an air cooled 250 Yamaha scrambler.
His thinking was that white was a better engine color than black due to it's reflectivity and would argue the point.
Even with all the factory black-engine bikes in the group.
He painted the engine VHT white, first time out, about 3-4 miles of hard running up a sand wash, seized a piston.
That was the definitive end of the argument for him....
Unkl Ian
11-27-2003, 01:35 PM
For HP,you want the pipes to stay hot.That's why some guys wrap their pipes with insulation.
The Jet Hot stuff seems to be very durable.But,everything else being equal,it looks just a little too much like spray paint fpr my taste.I wonder if they make the same stuff in Black?
There are other coatings available,for different applications,
including one that increases emissivity(sp).They use it on the brake calipers in Winston Cup to help radiate heat quicker.I wonder how it would stand up for headers?
I had the very same concerns as you have, Jay, when I was planning the blue roadster. The combination of outside runners and five feet of megaphone on each side of the car the potentiala for injury seemed to be rather high.
The lakes pipes had been part of the original scheme all the way back to my first roadster, however, so I opted for a program of care and education. I'd caution passengers to be careful not to lay a calf against the right-side pipe when entering or exiting the roadster. In actual fact, you have to place your right foot well under the car to come in contact with the megaphone.
Like you, I was especially concerned about children reaching out to touch the big shiny object and blister their little hands. As I'm sure you well know, fenderless hot rods are kid magnets. I took care in selecting parking spots that were out of foot-traffic patterns in parking lots. During the odd cruise-night adventure I'd stay with the car long enough for the pipes to cool down to a safe level.
Thanks to a bit of serendipity resulting from an unsuccessful hunt for excellent '33'34 torque-tubes, the system cooled down quickly to a point where it could be safely touched. In the '50s we could by excellent torque-tubes that still had a full coat of factory paint for fifty cents apiece. With a light buffing they were ready for plating. The best ones we could find in 1994 were rust pebbeled and would have cost hundreds of dollars to be polished to the point of being platable. We went so far as to have a tube skinned on a large lathe by a friend of Tardel who performed the task for free, seeing as how it was an experiment. There was still a couple-hundred dollars worth of metal polishing before the tube was ready for the tanks.
At this point I opted to buuild the system in 304 stainless -- flanges, runners, and megaphones. I order mandrel-bent J-bends for the runners from Burns Stainless. For the megaphones I turned to a friend who has a sheet-metal shop that does a lot of medical and wine-processing equipment as well as expensive architectural details. It was a big task and hardly cheap, although in the end it was less exspenive than having a steel system fabricated and plated. (As a plus, I prefer the look of polished stainless to that of plating.)
The serendipity came in the ability of stainless to quickly give up heat and cool down. Within five minutes of shutting off the motor, the runners and megaphones, while still warm, could be touched comfortably. My experience with plated exhaust systems was with motorcycles, and I have first-hand knowledge that it's possible to sustain a blistering wound a half-hour or longer after the motor was shut off. I'll bet Terry can explain the mechanism to us.
I do have some experience with ceramic-coated headers and they're as good as stainless for cooling down quickly. I had big-tube fenderwell headers on the 427 in my '46 Ford coupe, and even with insulated wrap they transmitted too much heat to the steering box and column, to the extent that the old original horn ring was uncomfortably hot after 10-15 minutes of driving. Opening the hood for a fluids check during a gas stop was like opening the door of a blast furnace. I shed the header wrap, blasted the headers and gave 'em a Ceramakote finish. Rather than re-invent the wheel, I include an excerpt from a how-to feature I wrote in AR years ago. The reduction in radiated heat is astonishing, and rather than just accept the word of the coating manufacturer I verified it with my B-in-L's electronic temp gun on my own car.
"In tests conducted at Competition Cams in 1991, a 468 cid Chevy Mark IV was dyno'd with one header coated with TLC's Black Satin ceramic and the other uncoated. Each header was instrumented with four probes: Two measuring exhaust gas temperature (EGT), one measuring surface temperature (ST), and one located 1-inch from the surface of each header to measure radiated heat. Ambient room temperature during testing was 60 F.
"According to Leonard Warren at TLC, the results exceeded even their expectations. During the test that generated the highest temperatures, where the EGT was over 1500 F and the ST exceeded 900 F, the RH of the uncoated header was 200 F 1 inch from the surface while the temperature of the Black Satin-coated header was 80 F 1 inch from the surface!"
In real-world terms, the steering box, column, and horn ring remained at ambient temperature, I could open the Ford's hood without risk of singed eyebrows, and within minutes of shutoff, the headers could be safely touched.
The local sprint car shop used to have a couple of identical headers hanging on the wall.
One chrome plated and the other Jet Hot.
The JH looked the best between the two, but thinking back on it, I'd bet the chrome header was not polished and probably plated with nickel, then chrome.
And maybe even chrome all by itself.
Biggest thing that bothers me about Jet Hot is having to send the headers away.
After spending many, many hours making a set of headers only to have them get lost somewhere in the system is more than I want to worry about.
Bad enough at a chrome shop where you don't want to take too many things in at once.
And speaking of chrome shops, a lot of times they have stuff that's finished and sitting in a back room cuz the owners didn't pick it up.
Every once in a while it gets sold out.
If the shop is an old one, you may be able to ask if they have any particular items they would sell.
That happens at machine shops as well.
Shiva69
11-27-2003, 01:53 PM
there is a company
techline coatings that makes a black thermal coating.
http://www.techlinecoatings.com/Retail.htm
they have a black there...
http://www.techlinecoatings.com/BulkExhaust.htm
in that link they have a clear ceramic coating as well
hope that helps a bit.
as for the color peice.
Black - gathers heat and radiates it.
white - reflects heat from the outside but won't radiate it away very well.
just what i remember from my high school science classes
Garth
Mike, thanks for the real world experience as well as the test information.
Nothing quite like bringing some daylight into the equation.
Although some Daylights are brighter than others....
I'd been thinking the shiny chrome/chrome looking headers would be the way to go, but satin black sounds interesting.
Especially so on an inside the frame set of headers.
Strikes me that it would be interesting on the outside headers as well.
Might go well with the minimal amount of chrome planned for the black w/yellow trim - this week - car.
Right now, the 4 links in back are chrome plated, but not too visible.
The batwings are stainless, the radius rods, spring perches, lower shock mounts get chrome.
Might get a little crazy and knock out another tie rod and drag link utilizing stainless this time around.
So far, I'm liking the blue powdered wheels with small Ford hubcaps as well as all the brushed aluminum stuff I've made for the car.
Still don't know about the beauty rings hanging in moms garage though.
Last time I was there she didn't want me out there and I didn't press it.
She's a bit of a pack rat and I would bet she has the car-less garage full of 'stuff.'
Sister took a look for me, but she doesn't really know what she's looking for.
So that's the latest on the beauty ring front in that area.
Maybe I'll just utilize Murphy ... you know, buy a re-pro set of rings and then mom will call and tell me she found some old hubcap thingys in the garage and I can come get them....
Jay -- The shiny silvery ceramic coatings perform essentially the same as the matte black coating in that they send the heat down the pipe rather than radiate it into the area they occupy.
BTW, with regard to the stainless system on a flathead . . . The EGT for a Ford/Mercury flathead is much lower than it is in a modern OHV/OHC configuration, although it's high enough to discolor chrome-plated headers. Stainless headers will gradually take on a wheat-straw tint extending a few inches from the flanges. This is easily removed with a bit of polishing, however.
The relatively low EGT comes from long exhaust tracts running through the waterjacketing, giving up some of their heat along the way. I've been struggling to devise a way to successfully coat the en-bloc exhaust runners in a flathead with ceramic to kick the exhaust heat out of the block instead of putting a lot of it into the cooling system.
Forgot to mention, Jay . . . I'm going to run cab stacks on my F-1 -- 2-inch, 16 ga 304 from Burns. About $150 delivered to Santa Rosa.I'll be using conventional tube headers fom Red Hamilton, with a ceramic coating, and feed the bad air through a pair of Flowmaster's new street-rod headers. Don't know if you seen this wonderful problem solvers, but they're not much bigger than a glasspack -- look a bit like a skinny catalytic converter -- and sound like a seasoned glasspack. Flowmaster gave Tardel a set to evaluate and he put them on his run-in stand. Damn! What a neat sound.
The stacks sound cool.
Wisht I had an early truck so's I could do it too.
Maybe so since I'm going to the dez to live.
A guy ought to be able to find something there.
Do the stacks have a turn-back to them?
Turn-back meaning not straight out the top, rather to the rear at an angle just above horizontal.
Gonna do the "drill an 1/8" or so hole in the lowest part of the tubing after the muffler" trick so's the overnight water from fog and rain will drain out?
Had a friend learn that one the hard way.
Sprinkled black stuff on his brand new white bed tarp.
Many bad words were spoken....
I haven't seen the new FM street rod muffs.
I'm running two chamber FM's on the 32 now.
A touch loud at idle and low rpms, but once cruising at light throttle they're fairly quiet.
Good thing is, they don't have that typical FM sound like you hear on a lot of late pickups.
That due to the 32's very short tailpipes.
I'd like to run three chamber FM's in the 32.
I have a set of these on my '02 SuperCrew with 5.4 liter and they sound very sweet indeed.
A bit like glasspacks from the good ol daze.
Even so, the new FM almost glasspack size sounds like a good way to go.
I can fit glasspacks up to about 30" or so in the 32, but that's about it.
Three chambers will fit the 31, but if I could have my Druthers I'd rather have a pair of 2 1/2" Hemi type muffs on it.
I'm into the music more than simply making noise.
Even though Hemi muffs are pretty quiet, I like their sound.
Specially so on a fat fender or a 50 Ford coupe.
I would think the thickness of the metal would have at least as much to do with the cool down rate as anything since the more metal there was to get hot in the first place the onger it's going to take to cool off.
That said, my side pipes have got me good twice and burned a nephew, neice mother in law and wife that I know of and I've see a couple of kids who's parents didn't train right, learn not to touch other people's property also
I amin the process of getting my pieces together for some stainless headers. We scored a semiload of 303 or 304 stainless! In my quest for header flange material, I found that Fastenal carries 3/8s and 1/2" flat bar stock in several widths. Prices range from .79 per inch to 2.00 per inch. You guys that have lots of industry nearby prob can find this stuff easily! The rest of us have to search. Fastenal is national so it should be easy to find a shop close to you.
The stacks will be straight, no turnback, just a baloney-cut outlet. Yes, they will have drain hole at the bottom, just inboard of the runningboard apron.
BTW, I'll order the pipe from Burns in straight lengths, 7 foot each, and then have them mandrel bent, 90 degrees one foot from the bottom, at Flowmaster where one of my youngest daughter's best pals is one of the fab wizards in the R&D shop. Sure is great to have kids connected in the industry; don't have to use up so many of my own favors. http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif
Trent -- I had header flanges plasma-cut from 3/8 inch 304 then I tidied them up on a Baldor belt sander before sending them to the polisher.
FWIW, I had the plater/polisher do the shine-up at several fabrication stages that made their work much easier. For example, I had them polish each of the runners once they were TIG'd together from individual segments. This permitted the polisher to get all way around each runner and blend the welded segments so they looked like they are continuous mandrel-bent tubes.
In the end, not only did I have a seamlessly polished exhaust system that wouldn't have been possible if they had to do it fully assembled, it cost me about 70 percent of what I'd have paid for a not-quite-perfect job.
Lotta good info in this post.
The polishing while things are apart and reachable is such a simple and good idea I wonder why it isn't done more.
Sure would have saved the guys at the chrome shop some effort when I had my 4 point 2 1/2" OD roll bar plated.
Darned thing sat for a month before they'd polish it.
Next time, I'll bend up the main hoop and have the visible part plated and then do the welding.
Protecting the chrome as I go.
The 32's roll bar is only plated down to about 6" below where it disappears behind the seat.
The rest got painted gloss black.
Not a bad combo and lots cheaper than plating the whole thing.
Hardly anyone is gonna see that part anyway.
Far as flange thickness goes, I've had very good luck with 1/4" cold rolled.
It doesn't/hasn't warped in use.
Gotta admit though, the slightly thicker stuff does look a little better.
If you saw the schedule 40 flathead headers I posted pics on a while back, the flanges on that are 1/2" and look cool.
An added bit of info about them is that they are actually a little lighter than the stock cast iron exhaust manifolds.
Since all I have to do to make the mocked up headers pictured above work on the Buick engine is weld in a short run of u-bend - about 45 degrees worth - and then clean up the one weld on each pipe plus stick on a collector, may make one of my own up for that.
Not so much the collector, but the ring and block-off plate.
Circular, six holes - maybe five as there's a bit of a five theme going on in other places on the car - drilled and tapped for 1/4-20 stainless allens on the ring and a flat 1/4" plate for the block-off.
I'm pretty sure some .063 relatively soft alloy aluminum will work for gaskets.
With a somewhat shallow step in both ring and block-off plate, a simple round piece of aluminum would be easy to make for the gaskets plus in the field repairs would be easy.
A few cut open beer cans stacked up and that would do it.... http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif
Good call on the polishing Mike. I planned on doing that myself. Since I polish my own stuff, anything that makes it easier is worth it!
Does anyone happen to have some formula/s for designing efficieant headers? I am going to do a form of a TriY into a 4" collector/dump.
river1
11-29-2003, 10:40 PM
lots of good info here!
just a little to add, jet hot comes in black, not a glossy black but a flat. flat radiates heat quicker.
C9 jet hot has a facility here in the phx area (tempe actually) so you could make a run down here after you move to kingman.
later jim
[ QUOTE ]
C9 jet hot has a facility here in the phx area (tempe actually) so you could make a run down here after you move to kingman.
[/ QUOTE ]
That's cool.
Thanks Jim.
Been looking up places in Kingman, Las Vegas and Phoenix.
Once I find a good metal supply house - preferably in Kingman, but ok in L.V. - I'll be set.
Only bad part so far is, no In & Out Burger in Kingman.
Five of them in Vegas and one in Henderson.
Gotta make some sacrifices I guess....
Jay, thanks for posting.
Mike, thanks for the info.
It is relevant to me as I am in the build process of my 47 coupe.
I have a roller, now, and will be placing the engine and transmission in the near future.
Then, it will be the exhaust system.
Although, mi exhaust will not be exposed to the casual burns, I am interested in the heat transfer qualities.
Thanks,
Jim
delaware george
11-30-2003, 11:03 AM
this is a great post...i'm suprised i didn't see hot pipes on the car alarm post.....there are alot of motorcycles sitting around mall parking lots with hot pipes...and you know how little kids like motorcycles http://www.jalopyjournal.com/ubbthreads/images/graemlins/crazy.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/wink.gif
Car alarm post?
Didn't see that one.
Little kids like motorcycles and hot rods as well.
I think because the wheels are exposed on the bikes and roadsters & coupes have a lot of shiny stuff on them in most cases.
The shiny stuff something rarely seen on modern vehicles.
I'm fairly conscious of kids getting burned on pipes because my five year old daughter slid off the gas tank of my dirt bike before I could stop her at the end of a short ride.
She didn't fall off, she was ready to get down cuz the ride was over.
She burned heck out of her leg on the exhaust pipe and I think she still has the scar.
When I was a little guy about four, I walked up to my dad's friends Harley that had just arrived and put my open hand on the finned barrel.
Burned heck out of my palm and fingers.
I was drawn to it's interesting texture due to the cast fins.
Somewhere between the ouchie and the crying I manage to kick the ol Harley a couple of times before they dragged me away from it.
AV8's comment about watching where you park and standing guard for the few minutes of cool down time ought to do it.
delaware george
11-30-2003, 12:05 PM
there was a post about what people use for car alarms etc. on here a while back,i figured someone would of used hot pipes to keep people from touching their car...there were some funny ones...delaware inspection won't let you run pipes and stuff like that...have to have a hood and fenders also...motorcycles are ok though http://www.jalopyjournal.com/ubbthreads/images/graemlins/confused.gif
zonkola
11-30-2003, 06:33 PM
[ QUOTE ]
Biggest thing that bothers me about Jet Hot is having to send the headers away.
After spending many, many hours making a set of headers only to have them get lost somewhere in the system is more than I want to worry about.
[/ QUOTE ]
I'd suggest calling some local shops that do powder coating. Many of them are expanding into the ceramic coating business, as the process is similar.
The shop I deal with offers something called "Cermachrome", which polishes up to an aluminum-like shine. Not quite as bright as chrome, but significantly cooler (temperature-wise) under the hood. It's very resistant to corrosion as well.
porknbeaner
11-30-2003, 07:15 PM
Every one has something to say right? http://www.jalopyjournal.com/ubbthreads/images/graemlins/smirk.gif
I been helping a friend sort out a Stude with a small block Chevy. Long story... Anyway, its got Chrome block huggers, they seem to get really hot and stay hot a long time.
We used to avoid chrome oil pans etc because they seem to hold the heat.
My experience is that black exaust cools quicker. I'd like to say that its cooler all the time but I think its probably an illusion. Don't have a heat gun handy to check.
I'm thinking about trying black ceramic coat on my next set, don't know if it will make a difference. Of course to afford the ceramic coat I'll have to sell a gold chain or two. http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif
Chrome would look really cool on the '31, but...
Did I mention that I hate chrome? http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif http://www.jalopyjournal.com/ubbthreads/images/graemlins/grin.gif
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