FYI Type 304 has a max working temp of 1400 degrees F BUT, is subject to stress corrosion cracking and to intergranular corrosion at temps between 800 to 1500 degrees F. Brinell hardness is 160.
Working temp for Type 321 is 1400 to 1500 degrees F; and in some instances, 1600 degrees. Not as subject to intergranular corrosion as Type 304. Brinell hardness is 150. Rich -----Original Message----- From: Clint Hooper <[EMAIL PROTECTED]> Sent: Jul 8, 2005 9:08 AM To: The Chevelle Mailing List <[email protected]> Subject: Re: [Chevelle-list] stainless headers Yeah,321 alloy is overkill for most applications. 304 is a very good alloy in its own right. Clint Hooper H&H Custom,owner 1969 El Camino ProTourer 2001 H-D FLHR custom bagger http://dalesplace.com/misc/friends/clint/clint_hooper.htm ----- Original Message ----- From: <[EMAIL PROTECTED]> Maybe I'll look into coating afterwards then, ill make sure the header fit first 321 is the best material for headers (after the very expensive inconel) but has the downside of a bit higher price. My understanding is that the rule of thumb is 304 for naturally aspirated and 321 for turbo or extreme conditions and inconel for guys with formula one cars or too thick wallets. I looked into building muself using Burns parts but only their 4-1 collectors are nearly $300 each (very nice), then add some tubing and some flanges and cones and stuff and you'll have $1000/1500 worth of parts and allot of work infront of you, then I've never built headers and I dont have a TIG so only that was to big of a challenge. André > The plus side of stainless steel,as you know,is the fact that the corrosion > problem is pretty much eliminated. However,one of the understated benefits > of exhaust coatings is their insulation properties. I'm not saying you have > to coat stainless headers. It's not mandatory to do so unlike mild steel > headers. However,it does help stainless,too. The 2" stainless steel headers > on my ZR-1 were made by Micron in England,who build most of the exhaust > systems used in Formula One. They were made of 321 stainless,a very high > grade,and cost over $1,200 back in 1998. Not trying to impress anyone but > the point I'm trying to make is that the cost to coat them at that time was > around $125,inside & out. Pretty cheap for less heat radiation and a few > more horsepower. > And people wonder why I'm not buying & building ZR-1's anymore. <g> > Clint Hooper > H&H Custom,owner > 1969 El Camino ProTourer > 2001 H-D FLHR custom bagger > http://dalesplace.com/misc/friends/clint/clint_hooper.htm > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > > > It sounded strange to me too that it wouldnt give any gain at all, but maybe > its > their marketing gimmick. > like "stainless headers are is a bit more expensive but you dont need to > coat them" > > André > >> As a general rule,I never buy headers already coated. I buy them uncoated >> and then send them to Performance Coatings in Oklahoma City to have them > do >> the job right. Chuck Simpson,the owner,was General Manager at HPC for over >> ten years and was part owner of Airborn Coatings. Chuck started his own >> business,Performance Coatings,back in the late '90's and they do all kinds >> of coatings,,and do them very well. >> As for coating stainless steel headers,it does make a noticeable > difference >> in slowing down heat radiation and makes for much cooler engine and >> passenger compartments. It certainly made a noticeable difference on the >> aftermarket stainless headers used on ZR-1 Corvettes. >> Clint Hooper >> H&H Custom,owner >> 1969 El Camino ProTourer >> 2001 H-D FLHR custom bagger >> http://dalesplace.com/misc/friends/clint/clint_hooper.htm >> ----- Original Message ----- >> From: <[EMAIL PROTECTED]> >> >> >> I have coated 3/4 lenght headers now and the coating is not good, it > rusted >> through >> the first winter, considering that the winters here are mostly 60F deg and >> rain two >> times a week I wont ever go with that again. >> I actually read in Burns catalog that stainless have much less thermal >> conduction >> than mild steel and therefore they dont need to be coated bacause that > would >> give no >> gain, of course stainless is their business but if they promote that there >> must be >> some truth in it at least. >> I'm not saying that all coatings are bad, but considering that shipping >> headers fore >> and aft over the atlantic to complain about possible pitting/rusting is >> expensive as >> hell I'll rather double the money right away and buy stainless. >> I also consider that my car is all custom and that if I have to move a > tube >> to clear >> something and reweld it it can be done with stainless but it cant be done > on >> e mild >> steel header without recoating afterwards. >> >> André >> >>> I'm very happy with the headers I bought direct from Jet Hot. They sold > me >>> Hooker Super Comps for a great price and hat them coated and the >> difference >>> is significant than buying them already coated. They do excellent work on >>> their coating!! >>> >>> Dan Mascheck >>> Wharton, TX >>> >>> _____ >>> >>> From: André-Tigergutt [mailto:[EMAIL PROTECTED] >>> Sent: Wednesday, July 06, 2005 1:10 PM >>> To: 'The Chevelle Mailing List' >>> Subject: RE: [Chevelle-list] stainless headers >>> >>> >>> Hi all, >>> >>> have anyone tried headers from stainless works? I know Clint proposed > them >> a >>> while back but I have no more than that. >>> >>> any other brand of stainless small block headers to consider?? >>> >>> thanks ! >>> >>> Have Fun >>> André >>> >>> >>> >>> >> >> >> >> >> >> > > > > >
