Do stainless steel headers cause overheating?

[Guest]

Hi,
Is it a bad idea to fit stainless steel headers? Will the bike run a lot hotter?
I know some are doing it, but does anyone know if it is really advisable?

[Dave8338]

Where did you get the idea that headers (stainless or not) make a bike run hot? If anything, the need for a rejet if you go with the 4 - 1 system and pods...MAY increase opperating temps slightly, however it has nothing to do with the header. You're just pushing more air and fuel through the engine, which is where the heat comes from. Headers on cars can increase the under hood temps as there is more surface area of the exhaust exposed, when compared to a cast manifold, but again, if anything, it makes the unmodded engine run cooler do to greater heat dissipation. :?

[Nessism]

Stainless headers are very common - ideal material for an exhaust I think. I can't think of any reasons they would make the bike run hotter other than due to jetting issues (common with any free flow exhaust).

[srsupertrap]

No, stainless steel headers will not cause overheating. I believe you will find availability quite limited and expensive unless you have a source from South Africa.

BR,
srsupertrap
original owner 79 GS1000E

[Joe Nardy]

Not at all! I have had a Supertrapp stainless system on my '83 GS1100 for at least 15 years. It still looks great and cleans up like new with a Scotchbrite pad......



Thanks,
Joe

[Matchless]

Thanks for the quick replies.
Why I brought this up was that I was told quite a few years back that some after market exhaust manufacturers will make a complete system for motor cars, but not the header (manifold) part from stainless steel. They prefered to rather make the header from mild steel. It was explained to me that stainless steel does not conduct and dissipate heat as efficiently as mild steel and the headers are used to conduct and dissipate some heat away from the actual head and it will not be as efficient if stainless is bolted right to the head.
I also asked the question as I have noticed that stainless is not used by OEM on headers and wondered why as a complete polished stainless system should not be more expensive than a chromed mild steel unit to manufacture?
I was wondering if an aircooled motor actually runs hotter with stainless and less heat conduction from the exhaust, even if only slightly.
I know it may sound as a bit of a stupid question to some, but I always like to be clear on these things as I am a complete novice in this area.

[Matchless]

Not at all! I have had a Supertrapp stainless system on my '83 GS1100 for at least 15 years. It still looks great and cleans up like new with a Scotchbrite pad......

Thanks,
Joe

Joe,
Very nice, running for 15 years tells me that it should definitely work. The condition of your bike also shows that you really look after it. I will try and get rid of my old rusty 4 into 1 sometime next year and will try and get one made up here as a ready built one will not be available here. Thanks for the picture and feedback.

[tone]

Ive run stainless systems on a number of gs's & z's over the years with no overheating problems that were not related to jetting :-D

some of the more modern bikes come with stainless exhausts now as stock some even have titainium :shock: (actually its a relitively cheap stainless titainium mix) & theres plenty of aftermarket exhausts available in either material so i guess there's no worries at all :-D

[psyguy]

i think you're quite right in your thinking - but the problem only relates to cars as they have the engine enclosed under the hood so any increase in temperature is not desired (especially if the air intake is under the hood too), so yes you do want to keep the temperature down in any way you can - including coating the headers inside and out with a special coating that reduces the heat and increases the flow of the exhaust gases
but obviously, all this is not an issue on motorbikes (at least road bikes)

Thanks for the quick replies.
Why I brought this up was that I was told quite a few years back that some after market exhaust manufacturers will make a complete system for motor cars, but not the header (manifold) part from stainless steel. They prefered to rather make the header from mild steel. It was explained to me that stainless steel does not conduct and dissipate heat as efficiently as mild steel and the headers are used to conduct and dissipate some heat away from the actual head and it will not be as efficient if stainless is bolted right to the head.
I also asked the question as I have noticed that stainless is not used by OEM on headers and wondered why as a complete polished stainless system should not be more expensive than a chromed mild steel unit to manufacture?
I was wondering if an aircooled motor actually runs hotter with stainless and less heat conduction from the exhaust, even if only slightly.
I know it may sound as a bit of a stupid question to some, but I always like to be clear on these things as I am a complete novice in this area.

[Matchless]

Hi psyguy,
Thanks for the reply. I was also wondering about idling at long robots, slow driving in traffic and the main thing being an aircooled engine. The new models obviously are liquid cooled and designed to different specs if they have OEM stainless headers. Most of the old GS bikes were never designed for stainless and also do not have temperature gauges so a rider would never notice overheating (especially if slight) unless it starts performing badly. But then you are right that in a car the closed engine space traps rising heat and will be more of a problem.
Someone recently wrote about stainless steel bolts breaking on the exhaust headers and I was wondering if this was heat related or overtightened as torque settings will also be a bit different if one wants to be clinically correct.

[psyguy]

do not have temperature gauges so a rider would never notice overheating (especially if slight)

sitting for too long in the trafic, i usually notice a slight increase in idling speed, a sign for me that the engine's running too hot
similarly, on an open road and cooler outside temperatures, when coming to a stop, sometimes the idling can be a bit lower even after a good run, again, a sign that the engine's not fully warmed
but, as you say, this is a clinical level of accuracy
and one cannot expect 30+ year old technology to perform like modern day would [-o<

[Matchless]

psyguy,
Well I have the answer from you and all the posters, it came through load and clear -no problem- and that whats counts the most.
I can now put this on next years list of pending expenses for a good cause!