Custom intake manifold? what material

[stevechumo]

Turbo manifold material

Stainless steel is very good for turbo manifold. However, it has to be thick 304. Mild steel made for cast steam will work well, but will rust after sometimes. In order for the turbo turbine to flow fast, it needs enough velocity to spin. Therefore, cast steam pipe flows better because it traps more heat in it, which resulting more velocity. For stainless 304, it'll last longer but less velocity. But both work good. It's up to you.

 

[quadcam boat]

I'm going to use mild steel for my inlet manifols and have it ceramic coated for corosing protection and looks. That way i can easily weld it up at home.

 

[88Alltrac]

Thick-wall 304 is what we used for turbo manifolds when I worked at two different shops. The fact that it is thick gives it great heat retention and it has a pretty high melting rate, preventing sagging and cast metal's cracking problems. By thick, I am talking .25" thick. There is nothing wrong with using stainless for intake parts but most go with aluminum for weight issues. Welding it can be fun for the inexperienced and the experienced will charge well for it.

 

[sly si]

steel to stainless

would it be ok to weld with 308 wire? cracking?? with pulse mig ..

 

[88Alltrac]

Should be fine as far as I know.

 

[cjsupra90]

just a little input on the cast bends that pro240c spoke about, they are cast steel not iron and weld up very nicely. they are actually refered to as weld els. they are alot easier to work with then stainless and are very strong. stainless (sus304 of sus321) does make for a good exh. material, but does need to be relitively thick to help eliminate the cracking problems. my seguestion for the exh. mani. would be the weld els and have the finished product ceramic coated. as for the intake, go with sheet metal not aluminum. reason being #1 steel is easier to work with and #2 especially if you are going FI and using an intercooled, steel has a far less thermial conductivity rate the aluminum. with a properly sized compressor and a good efficaint intercooler, the intake air temps will be lower then the engine bay air temps and therefore an intake made of aluminum will act as a heater to the intake air as aluminum has a higher thermial conductivity rate where as the steel will help block out the heat from being induced into the air charge. the term heatsoak applies very well here. this is why a lot of manufactures have gone back to steel fuel rails and thermial plastic intake mani.'s

 

[stevechumo]

aluminum has a higher thermial conductivity rate where as the steel will help block out the heat from being induced into the air charge. the term heatsoak applies very well here. this is why a lot of manufactures have gone back to steel fuel rails and thermial plastic intake mani.'s

I agree that aluminum has a higher rate of heat penetrating it; however, the advantage of aluminum is that it doesn't hold the heat as long as steel, which means it'll relieve the heat much faster than steel. That's why most pipes in the engine are made of aluminum instead of steel. This is not to include the lighter weight and the flexibility of it. Everything has been researched and done.