Modified 400EX header!!

[MAKO19]

Well guys I have been trying to keep myself busy in the barn this week and figured I would work on the 4 hundy. I kept looking at the ugly heat shield on the header so I took it off but then realized there are even uglier mounts for it underneath. Since I wanted this thing gone and I was planning on grinding down the factory welds anyway to get the most out of my exhaust system I removed the header and went to work.

I used a dremel with a small cutting wheel to carefully remove the mounts. After the mounts were removed I switched to a grinder bit to smooth down the left over welds. To finish the pipe and make it look like it never had mounts I switched the bit to a small sanding bit with 80 grit sand paper. The 80 grit at high speed really smooths things out. A little tip is to spray paint the pipe with flat black paint, let it dry and then hand sand it with 220 grit to see where the low spots are. Then you can go back to the dremel and sand only where you see bare metal and not remaining black paint. This is a body shop trick and will give you awesome results without removing excess pipe material.

The next step was to grind the factory welds down on the header inlets. I used an air dremel for this with heavy duty stone bits to minimize the amount of time it needed to complete the job, but a regular dremel would work fine. Just make sure if you have a battery powered dremel you have 2 batteries!

To finish the pipe I was originally going to stain it to match the existing bare metal by spraying it with WD-40 and heating it up with a propane torch. This worked to some extent but didn't give me the color I wanted. Time to initiate plan B. I went to Autozone and picked up some flat black VHT header paint 1300-2000 degree. VHT now has straight 2000 degree paint :devil: as well but they didn't have it in flat black which is the color I was going for. 1300-2000 degree paint should work fine on the 400 header since I used 1200 degree on my Monte Carlo SS headers and they still look like the day I painted them. I don't see the 400 generating exhaust temperatures hotter than a modified 350 small block but I will post results on that after I cure the paint tonight.

The final product looks awesome and only cost me 9 bucks for a can of paint since I had all of the other supplies in my barn. There is directions on the back of the can for how to properly cure the paint. To make it easier on yourself and your freshly painted header remove the air box and front plastics and tie the plastic air box inlet pipe off to the side. This will give you more room to install the header without bumping it into everything and scratching the piss out of it. If you do it right and have 2 people (or you are very careful) you can install it without scratching it. Remember this paint is very weak until cured and scratches easily. After it is cured it's almost bullet proof. I didn't cure mine last night because I finished up late and didn't think the parents would appreciate the HMF pipe idling at 11:30 p.m. I will do that tonight and post results and pics either this weekend or next week.

Hope this helps a few guys out.
Gary :D

[deathcorefan2]

pics of stfu.


kidding, but really, post up some pics..
and i dont think the heat shield is uglly...not if its painted right :D

[MAKO19]

Originally posted by deathcorefan2
pics of stfu.


kidding, but really, post up some pics..
and i dont think the heat shield is uglly...not if its painted right :D

I will...I will. In my opinion the exposed header looks 10 times better than the shield.

[deathcorefan2]

ill have to see..sounds like something i might do lol

[MAKO19]

Originally posted by deathcorefan2
ill have to see..sounds like something i might do lol

Yeah I'm at work now but I will snap a few pics tonight when I get home and try to post them before I go out for my usual Friday night shenanigans.

[deathcorefan2]

Originally posted by MAKO19
Yeah I'm at work now but I will snap a few pics tonight when I get home and try to post them before I go out for my usual Friday night shenanigans.


haha im at school :devil: i shouldn't be on here.

[Which 450?]

the exposed header also melts to your skin 10 times quicker then the shield!!!

[MAKO19]

Originally posted by Which 450?
the exposed header also melts to your skin 10 times quicker then the shield!!!

No $hit really? I posted this to be helpful to people who might want to consider doing this. How many bikes have we all seen with performance headers with no heat shield. It's just an inexpensive mod that will also improve the looks of your bike. I don't ride with shorts on anyway moron. Go post crap in other people threads.

[Pappy]

Originally posted by MAKO19
No $hit really? I posted this to be helpful to people who might want to consider doing this. How many bikes have we all seen with performance headers with no heat shield. It's just an inexpensive mod that will also improve the looks of your bike. I don't ride with shorts on anyway moron. Go post crap in other people threads.

You sound like the moron. The man wasnt downing you or anything you did, just pointing out that it will be easier to burn yourself.

[MAKO19]

Originally posted by Pappy
You sound like the moron. The man wasnt downing you or anything you did, just pointing out that it will be easier to burn yourself.

Come on dude like anyone wouldn't know that as they are cutting it off. I'm trying to be helpful and keep stuff positive. I realize I am the new guy here and what not but this is not the only message board I am a member too and not the first time pointless replies have been posted on my threads. It's nothing new to me .:rolleyes:

[buck440]

hey chicks dig scars. i wish i had the tools to do that to mine also cause man that shield is fugly.

[MAKO19]

Alright, I'm gettin outta this office. Time to go have some fun. Gonna cure the paint and post pics sometime this weekend or early next week the next time I am near a computer. Have a good weekend fellas.

[Pappy]

Originally posted by MAKO19
Come on dude like anyone wouldn't know that as they are cutting it off. I'm trying to be helpful and keep stuff positive. I realize I am the new guy here and what not but this is not the only message board I am a member too and not the first time pointless replies have been posted on my threads. It's nothing new to me .:rolleyes:

Maybe you should stay on other sites, your attitude wont fly here

[Which 450?]

Wow, lol, some people!

lawl lol yeah i've burnt myself on both header and heatshield. header is an instant burn off the skin and blister which may follow with bleeding and shouting and pain for quite a bit of time. heat shield is a ouch little blister. I alsways thoug of why not put heat reflective tape on the backside of the heatshield? I would think it wouldnt get as hot. I wear boots so heat isnt a problem on the legs but I still wouldnt mind having a cooler heat shield incase. What about on the oil cooler too putting the reflective tape?

[Pappy]

Other models have heat tape shielding the inside of the guard, so doing it makes sense. It is possible that some reflective heat tape could shield some of teh heat off the cooler from the headpipe. I cant imagine it hurting a darn thing:p

[beags86]

i just wraped my whole header in exhaust header wrap for automotive headers, and it seams to be cooler on the leg alot. i am going to unwrap it and get a heat gun and test the before and after temps. although it seams cooler on the leg, the other day when i rode it was also 36 degrees out. i will be doing some before and after tests with the header wrap and air scoops(when i get them built). stock, vs wrapped header and stock vs air scoops and stock vs both. there seams to be some debate on whether or not the air scoops work, well i am sure they make some diff, which i will find out for sure and post the results. i also feel the need to prove the wrap because a buddy, (a member and a 400 rider) says the wrap doesn't work and just looks ugly.
well if my nitrous feed drag car likes wrapped headers why wouldn't my 400ex?

[bigbad400]

if you get moisture in behind the tape your exhaust will rust out raster than 2 shakes of a jack rabbits ***, that stuff is made for 8 seconds at a time in perfectly dry conditions, with heat that would otherwise melt a header on a nitro burning drag car, your 400 wont like having rust holes in the header, and if you got an aluminum header you dont need to worry about heat disipation, it should be cool enough, if you have stainless header then i wouldnt recoment it either you can make stainlees brittle by doing things to the heat treatment in the metel, in other words.... come prepared to ride,(pants and boots) and you wont need to fret about things that are meant to be hot, i never even so much as noticed a warm spot, after 8 hours of riding i could lite a smoke off the header, but never did it burn me or even get to hot to make me think about doing anything to it. i do think those shields are ugly thow, someone should make a custom one that looks cool as hell, like a snake backbone or something winding down the pipe to the split

[beags86]

Originally posted by bigbad400
if you get moisture in behind the tape your exhaust will rust out raster than 2 shakes of a jack rabbits ***, that stuff is made for 8 seconds at a time in perfectly dry conditions, with heat that would otherwise melt a header on a nitro burning drag car, your 400 wont like having rust holes in the header, and if you got an aluminum header you dont need to worry about heat disipation, it should be cool enough, if you have stainless header then i wouldnt recoment it either you can make stainlees brittle by doing things to the heat treatment in the metel, in other words.... come prepared to ride,(pants and boots) and you wont need to fret about things that are meant to be hot, i never even so much as noticed a warm spot, after 8 hours of riding i could lite a smoke off the header, but never did it burn me or even get to hot to make me think about doing anything to it. i do think those shields are ugly thow, someone should make a custom one that looks cool as hell, like a snake backbone or something winding down the pipe to the split


i'm well aware of the whole rust issue. i really doubt it will be a problem on my 400 i painted my header with some high temp paint, plus you always have the engine heat burning any moisture out. and if i am wrong and your right,then i'll have a reason to buy a full pipe hehe

and the reason for this is not about the heat on my leg, (i posted about this here because i thought it was relevant info- and i will post my results here) it's about performance. and not about the leg heat of looks. a cooler engine performs better..... period. and and header wrap makes for a cooler exhaust and a cooler engine.... period.

[MAKO19]

Ok the paint is cured and everything is good to go. I followed VHT's directions and then went to the woods for a 1/2 hour rip and everything is holding up beautifully!! I borrowed a temperature sensor gun from the engineering firm I work for and even after a 1/2 hour ride the hottest reading I got was 700 degrees F surface temperature at the header inlets. The temperature cools pretty drastically as your go toward the muffler and I was getting 250 degrees at the muffler inlet. So to answer anyone's questions 1200 degree paint will work just fine.

Here are some pics of the final product. The quad feels like it maybe picked up some too after grinding the welds down.

http://www.myfishpix.com/gallery/data/500/400_Side_Shot.JPG

http://www.myfishpix.com/gallery/data/500/medium/Header_Blow_Up.JPG

[RATPACK Z400]

You know what would be better than coating is to make a cooler looking heat shield out of alum.

[jkulysses]

Eko can make a heatshield out of carbon fiber that looks really good. I guy over on the .org had one made and it turned out pretty nice. To spendy for me though. I used heat tape and sealed it real good with the thermal tec sealer and it came out real nice. Looks good and it cut the heat easily in half.

What you did does look good though in my opinion but I love the blacked out look on almost anything lol.