mrbeige 0 Posted March 4, 2008 Alright guys! I need some advice. I have a mate who is a bloody good TIG welder, who works for a company making commercial kitchen equipment. He said he'd weld up a manifold, if I mock one up. So rather than spending a schitt load on an exhaust manifold off the shelf, I thought I'd try and put one together (a la cheeswire downpipe stylee) and get him to weld it up. He can get the steel and also get the pipework bent to various radii for me to work with. What I need to tell him is the type of stainless I should use, as he only knows about food grade stainless (which is bloody expensive!), how thick it needs to be, what diameters it needs to be and also how thick the head side flange and the T3 turbo flange need to be. Any advice welcome. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted March 4, 2008 I'd use 15mm thick 304 for the flanges and 321 or 321H for the runners. 304 buckles with heat and will need machining flat again after welding, hence the 15mm thickness. Gives you some meat to play with. You want at least 12mm thick flanges in the finished product. 321 is the best stainless for heat resistance and flexing strength, so best for the runners. 321H has extra carbon content for even higher resistance to heat. The Primaries need to be the same bore as stock to keep the gas speed up, but as for wall thickness, I'm not sure mate. See what's available. I reckon around 2.5mm is about right.... depends what your man can work with. This is the kind of thing to aim for. Notice the primaries are tacked together for strengthening. Quote Share this post Link to post Share on other sites
antonio_b12 0 Posted March 4, 2008 Thats a bloody good looking manifold :notworthy: I Wouldn't use anything less than 316 stainless steel material, if you can get 321 even better 8) If you need a T3 flange, i may have one available. Quote Share this post Link to post Share on other sites
mrbeige 0 Posted March 4, 2008 Righto, so 304 for the flanges and 321 for the runners. 2.5mm seems sensible enough, can anyone confirm if that is adequate? I sold my bloody manifold didn't I :( Anyone know the thickness of the 9a manifold If you need a T3 flange, i may have one available. Hmmm, that could be a good start :) How much do you want for it? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted March 4, 2008 Thats a bloody good looking manifold :notworthy: It's the one my mate had made 8) It's not quite finished yet, but it should be a nice peice when finished :) Righto, so 304 for the flanges and 321 for the runners. 2.5mm seems sensible enough, can anyone confirm if that is adequate? I sold my bloody manifold didn't I :( Anyone know the thickness of the 9a manifold Do you mean the 9a exhaust manifold? Good cast turbo manifolds have around 1/4" wall thickness, but stainless doesn't need to be thick. The thicker the wall thickness, the harder it will be to work with. Cutting and finishing normal 304 with normal tools is tricky enough, let alone 321?! :lol: I'm sure 2 to 2.5mm rings a bell, I'll check with the place that made that one. Quote Share this post Link to post Share on other sites
mrbeige 0 Posted March 4, 2008 Do you mean the 9a exhaust manifold? Good cast turbo manifolds have around 1/4" wall thickness, but stainless doesn't need to be thick. The thicker the wall thickness, the harder it will be to work with. Cutting and finishing normal 304 with normal tools is tricky enough, let alone 321?! :lol: I'm sure 2 to 2.5mm rings a bell, I'll check with the place that made that one. I was thinking of the diameter of the runner rather than the thickness of the runner wall. My mate is used to working with food grade and surgical grade steel, so I'd imagine that the 321 stainless shouldn't pose him too much of a problem. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted March 5, 2008 I'd do the runner's internal bore the same size as the head port. Quote Share this post Link to post Share on other sites
mrbeige 0 Posted March 5, 2008 I'd do the runner's internal bore the same size as the head port. Ah, of course! My mate is gonna find out today about prices etc. I'll proly have to buy a newspaper sized piece of flat stainless, but I suppose that could be used for other stuff too. My Dad has a pillar drill, that I might have to lay my hands on too!! :lol: My mate said he has no problem with welding the sttel, so that is a good start. If it turns out well, I might do a couple of three and sell them. Might even pay for the steel... Quote Share this post Link to post Share on other sites
antonio_b12 0 Posted March 6, 2008 pm sent about the T3 flange Quote Share this post Link to post Share on other sites
fastinox 0 Posted August 4, 2009 Hello, If you are looking for 321H stainless steel pipe and fittings, I have it in stock. 42.20mm OD x 3.56mm wall for all pipe, 90deg elbows and 45deg elbows. Email me at [email protected] if you would like some good prices!! Simon Quote Share this post Link to post Share on other sites
