OldNathan Posted February 9, 2016 Share Posted February 9, 2016 Hey guys so I'm just trying to see if there is a way I can flare a 38.1mm short radius mild steel bend out to about 46mm. Everyone I've spoken to has suggested flaring out a 38mm straight tube out to 46 and then cut it off and weld it onto the 38 bend. I'm kinda wanting to not do that buy rather see if anyone can flare the bend itself. Exhaust shop has said they probably can't get the flare tool in far enough and even then it will be a sharp decrease from 45 to 38. Where as a cone pressed on will give it a more progressive flare. Are there any other options any of you guys might know of. As soon as you mention cars people switch off. Also to note this is for an intake being welded from a 10mm flange to another 10mm flange for throttle bodies. Quote Link to comment Share on other sites More sharing options...
downtrail Posted February 9, 2016 Share Posted February 9, 2016 Would be easier to make a cone to do that use a program called cones find the older one thats freeware input your dimensions print out. Stick to sheet cut and curl it up and weld it on. Not what you wanted to hear but thats how id do it. Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 9, 2016 Share Posted February 9, 2016 Machine a 81 / 9 degree chamfer in the 10mm flange. If my tired physics/maths brain is correct with right angle triangles, then that will step it down from a 46mm on the front side to a 42mm on the back side of the plate. Weld on 42mm tube and then chamfer the other 10mm flange the same 81 / 9 degrees from 42mm to 38mm. This is assuming you haven't had the flangess made yet or bought the bends. If you have had the flanges made then investigate inserts to achieve the same effect as what I suggest, plus you can have them machine a small flange on it to sleeve inside the bends. If you have bought the bends then buy some new ones. All impractical and spendy but the best way to achieve whay you want, all in my opinion of course. Quote Link to comment Share on other sites More sharing options...
OldNathan Posted February 9, 2016 Author Share Posted February 9, 2016 Ah issue being the 38.1mm is squished to an oval which fits perfect to weld to engine side plate Quote Link to comment Share on other sites More sharing options...
OldNathan Posted February 9, 2016 Author Share Posted February 9, 2016 Which has been made Quote Link to comment Share on other sites More sharing options...
KKtrips Posted February 9, 2016 Share Posted February 9, 2016 Is the throttle body end round? It may be a 72 / 18 degree chamfer you need to do in just the top flange. Get someone smarter than me to double check my maths. It's late and I'm stupid. Alternatively, assuming the pipe is 1.2mm wall 38.1mm id plus 2.4mm wall is 40.5mm od. So only 2.5mm gap around each pipe to fill if you slide it inside the TB flange which is easily doable plus if you weld it inside and out then you can dremel a wee chamfer inside the pipe from the TB end. 1 Quote Link to comment Share on other sites More sharing options...
OldNathan Posted February 9, 2016 Author Share Posted February 9, 2016 Yes throttle body side is 45mm round Quote Link to comment Share on other sites More sharing options...
Steelies Posted February 9, 2016 Share Posted February 9, 2016 how many of these do you need to do, and have you considered hammer, anvil and some sort of cone-ish gauge? Quote Link to comment Share on other sites More sharing options...
OldNathan Posted February 9, 2016 Author Share Posted February 9, 2016 I need 12. I had thought of that but would probably head down the route of flaring a straight piece and welding to a bend before that one. The intake will be seen and if I did something like that you wouldn't want to. Quote Link to comment Share on other sites More sharing options...
Rookie Posted February 9, 2016 Share Posted February 9, 2016 Definitely download a cone program and make them out of sheet metal, I would use 1.6mm stainless, I had great success making spannys and my dry sump tank that way. 1 Quote Link to comment Share on other sites More sharing options...
Roman Posted February 9, 2016 Share Posted February 9, 2016 The bend on each one doing a 90 deg turn to lay throttles down flat right?  For sake of non shitty flow I'd be inclined to look at having the bend made from the 45 ID pipe. Then use something thick walled welded to the flange that you can die grind a transition into the 38mm oval or whatever.  Time consuming doing 12x, but maybe the cheapest option that isnt going to have crappy flow into the head. Or otherwise if you dont have the height for that. maybe get a 45mm ID 90 deg bend, and then split it down the middle with a bandsaw. Then squash the ends down to 38mm and cut a taper so it transitions nicely. You'd also get a good transition in cross sectional area across the whole length of the piece.  Which again, is time consuming but that's V12 life!  Unless you think it looks ugly I wouldnt be shy about spacing the throttles further away from the head than what you're currently planning. As it might make things easier and your total runner length will want to be reasonably long anyway. If you can show us some photos or sketches of what you're wanting (it's a 90 deg bend right?) then I can try sketch up a few options in cad that might work well and be easy to fabricate. Quote Link to comment Share on other sites More sharing options...
OldNathan Posted February 9, 2016 Author Share Posted February 9, 2016 Bang on will do some sketches over lunch. Thanks for the input guys. Quote Link to comment Share on other sites More sharing options...
OldNathan Posted February 14, 2016 Author Share Posted February 14, 2016 Hey sorry I didn't post up the drawings I managed to find the perfect piece to this puzzle. So I'm buying 12 on Monday and it starts getting tigged up. 3 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted February 14, 2016 Share Posted February 14, 2016 Will look bloody nice in the dairy tube you have! Make sure ya purge it or the insides will be yucky. Can't wait to see pics! Quote Link to comment Share on other sites More sharing options...
OldNathan Posted February 14, 2016 Author Share Posted February 14, 2016 Cheers mate. Yeah my welder friend is purge welding it. Will update my build thread once it's done. Quote Link to comment Share on other sites More sharing options...
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