Choice of materials for exhaust manifold.
12-25-2005, 08:33 PM
#21
1.5 BAR
Join Date: Feb 2005
Posts: 691
Re: Choice of materials for exhaust manifold.
Originally Posted by slappynuts
Alot of the 1.9t VW guys(elitist ****** :P) have alot of problems because they run high boost and extremely high EGTs.
12-26-2005, 05:47 PM
#23
3.0 BAR
Join Date: Dec 2002
Posts: 12,568
Re: Choice of materials for exhaust manifold.
theres ur first prob, sched 10 stainless els i get em for 4.25 a piece.
mild steel is just flat out not worth it. people arent willing to pay anything for a mild steel mani, evwen though it costs just as much to make.
mild steel is just flat out not worth it. people arent willing to pay anything for a mild steel mani, evwen though it costs just as much to make.
12-26-2005, 08:11 PM
#24
1.0 BAR
Thread Starter
Join Date: Oct 2005
Posts: 216
Re: Choice of materials for exhaust manifold.
Originally Posted by hotrex
theres ur first prob, sched 10 stainless els i get em for 4.25 a piece.
mild steel is just flat out not worth it. people arent willing to pay anything for a mild steel mani, evwen though it costs just as much to make.
mild steel is just flat out not worth it. people arent willing to pay anything for a mild steel mani, evwen though it costs just as much to make.
SCH 10 is half as thick as sch 40.If you have a big enough welder you can lay in a much stronger weld.
12-27-2005, 12:17 AM
#25
3.0 BAR
Join Date: Dec 2002
Posts: 12,568
Re: Choice of materials for exhaust manifold.
you dont get slag in the mani if you take a few minutes and make some sheet metal shields for the runneres ect.
tinfoil also works good.
thwe siley plasma cutter burns through sced 10 like butter.
tinfoil also works good.
thwe siley plasma cutter burns through sced 10 like butter.
12-27-2005, 01:58 AM
#26
Banned
Join Date: Aug 2003
Posts: 2,898
Re: Choice of materials for exhaust manifold.
Originally Posted by slappynuts
Mild steel manifolds last longer.
12-27-2005, 06:00 AM
#27
1.0 BAR
Thread Starter
Join Date: Oct 2005
Posts: 216
Re: Choice of materials for exhaust manifold.
Originally Posted by hotrex
you dont get slag in the mani if you take a few minutes and make some sheet metal shields for the runneres ect.
tinfoil also works good.
thwe siley plasma cutter burns through sced 10 like butter.
tinfoil also works good.
thwe siley plasma cutter burns through sced 10 like butter.
12-27-2005, 05:33 PM
#28
1.5 BAR
Join Date: Feb 2005
Posts: 691
Re: Choice of materials for exhaust manifold.
At the shop I work at, we'll make about 2000 cuts on one bandsaw blade.
They are supposed to last over 3000 cuts, but we punish the saw and use lots of SS for some production projects.
The blade for our Ellis costs about $70.
If we only cut mild steel, that blade would cost about $40.
So for stainless our price per cut is about 3.5 cents and for mild it would be about 2 cents.
I'm going to guess you make 25 cuts per manifold.
That comes to a total savings of 37.5 cents.
Conclusion - By using mild steel you save 37.5 cents per manifold to cut.
They are supposed to last over 3000 cuts, but we punish the saw and use lots of SS for some production projects.
The blade for our Ellis costs about $70.
If we only cut mild steel, that blade would cost about $40.
So for stainless our price per cut is about 3.5 cents and for mild it would be about 2 cents.
I'm going to guess you make 25 cuts per manifold.
That comes to a total savings of 37.5 cents.
Conclusion - By using mild steel you save 37.5 cents per manifold to cut.
03-29-2006, 11:24 AM
#30
1.5 BAR
Join Date: Aug 2003
Posts: 1,164
Re: Choice of materials for exhaust manifold.
Sorry to bring this back from the dead but i have been doing some research on this topic and found some good info.
http://www.burnsstainless.com/TechAr...s_article.html
Its a really good article and if you know anything about thermal equilibrium diagrams you might get a little more out of it. At the bottom it shows the modulus of expansion for mild and stainless steel and mild is 7.228 while stainless is 9.9 so it doesnt expand that much more. Also if you look at the thermal conductivity you can see that stainless is a much better choice for a manifold since you want to keep the heat in so you can keep your velocity up.
http://www.burnsstainless.com/TechAr...s_article.html
Its a really good article and if you know anything about thermal equilibrium diagrams you might get a little more out of it. At the bottom it shows the modulus of expansion for mild and stainless steel and mild is 7.228 while stainless is 9.9 so it doesnt expand that much more. Also if you look at the thermal conductivity you can see that stainless is a much better choice for a manifold since you want to keep the heat in so you can keep your velocity up.
