Fixturing an intake manifold

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A customer dropped off an intake manifold that needs a little milled off. After looking the part over I found it has some fixture features cast in. Nice. I tried balancing it on blocks but that was like herding cats. So, I sawed up some 1.5x2 aluminum bar and laid it out on that. It was still hard to keep it all together... so I hatched the brilliant plan to just tack the bars together. In hind sight I should have bolted them. I know my machine is way too small... but I didn't need much I thought. I had to preheat the devil out of the bars and even still I could barely eek out enough heat to build a puddle. After a lot of gas I finally had it together. I then drilled some holes for the table and bolted it down. It actually a slick fixture. Slip the intake up against the back stop and then slid the front bar in. Couldn't be easier.I was going to title this thread... "What? Why can't I weld 1.5" aluminum with my 180 amp tig? " But I decided to keep the topic of the fixture not the madness of it's author.
Reply:I must be living right. I'm mighty close without any shimming. I'll hit it with the indicator but the level shows I'm in the ball park. I'll finish this up on Monday.
Reply:Are you taking metal off the runners where they meet the head?  I have always wanted to be able to do that, but could never figure out a way to index the manifold.  On most V8's, when you take .010 off the head, you need to take .012 off the intake to match them up.  .030 off the head means .036 off each side of the intake manifold.  Keep us posted on results.Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:Originally Posted by DougAustinTXAre you taking metal off the runners where they meet the head?  I have always wanted to be able to do that, but could never figure out a way to index the manifold.  On most V8's, when you take .010 off the head, you need to take .012 off the intake to match them up.  .030 off the head means .036 off each side of the intake manifold.  Keep us posted on results.
Reply:Ah yes, I see the line now.  Hope it goes well.  I would have bet money you couldn't weld aluminum that thick using a 180 amp machine with a regular tig torch without some serious preheat (almost to the point of melting the aluminum).Miller Syncrowave 350Millermatic 252/ 30A spoolgunMiller Bobcat 225g w/ 3545 spoolgunLincoln PowerArc4000Lincoln 175 Mig  Lincoln 135 Mig Everlast 250EX TigCentury ac/dc 230 amp stickVictor O/AHypertherm 1000 plasma
Reply:Randy your machine shop post are really great.  I know very little about machining and I learn a lot from your post. Thanks and keep it up
Reply:I think I would have just bolted them together.
Reply:Well this little job is done. I used a 2x4 and drew it down level on the fixture. I ended up shimming one corner that was high. Worked great. Finish turned out good. Easy.