tubular exhaust manifolds

[timucin]

my friend gave me a good deal for building tubular exhaust manifold.prices are too high in your countries, even if you arrange group buys.
if you are interested i can organise a group stuff from here.there is no sample for the moment, but if there is interest i will post pics in two weeks.

i am talking about half of the best price offered untill now...


*note: just an idea, nothing ready for sale,if you are interested i will collect full info .

[Flexx]

my friend gave me a good deal for building tubular exhaust manifold.prices are too high in your countries, even if you arrange group buys.
if you are interested i can organise a group stuff from here.there is no sample for the moment, but if there is interest i will post pics in two weeks.

i am talking about half of the best price offered untill now...


*note: just an idea, nothing ready for sale,if you are interested i will collect full info .

1st of all, u need to check out, which material etc...u know the exhaust temperature is about +/- 1000 degrees celcius...

It's not easy to build a exhaust manifold for a high range S2/RS2...he must a profi to build something like that

[timucin]

he is the best man around. we will see

any suggestions about material?

[Corey]

he is the best man around. we will see

any suggestions about material?

Either 304 or 316 stainless steel or if money no object Iconel.

[Pisobiker]

he is the best man around. we will see

any suggestions about material?

AFAIK best SS for such a job is #321. Good strenght and high termal stability.
Not so easy to find and quite expensive.

Second best is #316, normally used for alimentary purposes. Easyer to find and less expensive than #321.

#304 is the most common SS available, but seems not completely suitable for the collector where temps go very close to 1000°C and the assembly also has the turbocharger hung....

SS also has a pretty high termal expansion which makes it prone to cracking.


Other than SS, mild steel might be the alternative. Needs appropriate corrosion protection, though.


Other than that is INCONEL 713.....

just kidding, of course. Way out of budget



Anyway Timucin, with all the respect for your friend who will surely know his stuff, main problem with a tubular exhaust header (apart from the right design, sections, lenghts and balancing among the runners) is resistance to cracking. I will probably make one myself sooner or later but I could not be sure it to be fine until having tested at extreme conditions for some k kilometers.


Marco

[timucin]

is there any brand which you all can say that it is the strongest,best designed em?

[Pisobiker]

is there any brand which you all can say that it is the strongest,best designed em?

Not having the blueprints with all the important dimensions, it's hard to tell....

From a theoretical point of view EM on a turbocharged engine should have smaller diameter runners as possible accordingly with flow needs, and this usually shouldn't exceed significantly total section of the two exhaust valves.
Smaller if low rpm responce is needed, at the expenses of max hp.

About runner lenghts these shuld be the shortest possible accordingly to have them all of same lenght.
Equal lenghts is really important only if you absolutely need the very top Hp possible, otherwise small differences shouldn't be a big problem.
Dial with lenghts is: turbine efficiency is very sensible to changes of speed, so to minimize fluctuations, pressure pulses should arrive to the impeller at steady frequency.

[Lee]

Inconel 625 will do for me please!