How to determine Header Quality

Quality can be initially seen during the physical inspection of a header. Tubing welds should have an even, high, convez appearance as flush or concave welds usually indicate that the weld bead has drooped inside the header tubing. On Flange welds, one should look for pinholing - small holes about 1/32" in diameter - that appear whenever heli-arc welding is improperly done and oxygen makes its way into the weld puddle. Extensive pinholing or larger pinholes are to be avoided as reduced header strength and early header burnout results from it. Gasket surfaces - header flanges, collector flanges, pipe flanges - must be flat to ensure proper, leakfree sealing. In order to ensure flatness, these gasket surfaces should be ground flat after welding to remove any weld bead and/or compensate for any flange warping or uneveness. However, surface grinding can also create problems so watch for this as well.

Quality shows up in a header as it lasts against time. This is where externally brazed headers and Heli-Arc welding the tubing to the exhaust flange come in handy. It makes the headers stronger, as the brazing puts additional metal where all the heat and stress is concentrated allowing the header to resist burnout and flange weld failure.

Quality can be observed elsewhere than the header itself. Example: Instruction Sheets. Quite often instruction sheets are too short and do not take into account the limited experience of most installers. Some instruction sheets are too general and say very little about the specific installation. Others concentrate too much on congratulating the consumer on his/her wisdom (?) in selecting their brand of header. A lot of this is done solely to mask design flaws, so you won't know until you attempt to install them.

Quality can be seen where a definite construction improvement is made ove rthe methods used by others. Example: either because of chassis limitations or installation reasons, somtimes a header has to be designed with one or more header tubes removable from the rest of the header. Because of cost reasons and easier production header jigging, most manufacturers use slip flittings - one part of the header tube is expanded to slip over the other part of the header tube. Slip fittings have several drawbacks, including: (1) slip fittings tend to leak as they don't usually fit together as tightly as possible. When muffler clamps are used to tighten the slip fittings, they usually distort the slip and it will not come apart later on. (2) in time the slip fitting will rust together and the header has to be cut apart during removal. (3) sometimes the slip fittings are located where they cannot be tightened or sealed in any fashion, so if they leak, the owner is doomed to listen to the noise from then on. (4) sometimes the slip fittings are located where it is extremely hard to slip the header together or apart. (5) a slip fitting tends to weaken the strength of a header. To counteract all of these problems, instead of slip fittings, welded flanges with gaskets bolted in between should be used.

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2001 Honda S2000
201.63 whp : 135.74 ft/lbs