Cylinder head port welding help

admin

Hi Guys - I could use some help with welding in really small motorcycle head exhaust ports.  I've already done lots of reading of past posts both here and on the Miller board.I've got two main problems - one is power - I don't have enough.The second is the size of the ports - they're really small and I can't reach in as far as I need and direct the arc where it needs to go.Attached are some photos - the first is an unmolested port from an early head.  What I'm doing is filling in the floor of the port, both to make it smaller and to change the shape of the port.  These are Honda heads from CB/CL175 vintage racers, circa 1965 to about 1972.  The second pic is a partially modified port, and the third is a partially modified port on a later model head with even more shrouding around the port, making it even harder to reach in the port.I'm using a Syncrowave 180 on AC, straight argon 20-25cfm, a wp20 torch with 1/8" pure tungsten and a #5 cup.  3/32 4043 filler (though it sounds like I should be using 5356 filler).  From the reading I've done it sounds like I'll want to try helium gas, either in about a 50-75% mix with AC and the syncrowave, or straight helium and DCSP.  I do have an XMT300cc/cv and a hf-251 box, so I could set the wp-20 torch up on the XMT and that would entirely solve the power problem if DCSP is the answer.  For that matter I could finish building the second water cooler I've got all the parts for, and use my spare WP20 torch with the non-flexy cables on that welder too...  :-)  Of course I could also try DCSP with my current setup easily and that's what I'd do at first if that's the way to go.I've been watching ebay for a super deal on a Smith's mixer like Zapster, but so far no joy.  For experimentation purposes I'll probably just get a bottle of helium and a y fitting and try approximate mixing.  These don't have to be super quality welds - I need to be able to build up and grind back down to the shape I need - anything will be an improvement so I suppose even some inclusions would be ok, though I'd prefer not.I've been shoving tin foil in the port from the back (valve) side too, and that helps with oxy contamination (the port makes a nice venturi drawing away the argon) and also allows a bit more tungsten stick-out before it becomes a problem, but I'm definitely pushing the limits all the way arould with as far in as I want to change the port shape.The best success I've had so far is putting a bit of filler in the middle of the floor and blending it in further with arc force, but that's both difficult and I've really not got enough power for it.  It may prove to be much easier with some helium in the mix and/or more power.Will DCSP and a sharpened tungsten allow me better control of the arc?  I've got lots of arc wander to other parts of the port right now - I can barely get any angle at the floor of the port as far in as I need to be welding.Anyone got any other tricks for welding around a corner - special Arc Bender to go with my can of blinker fluid and box of muffler bearings?  Thanks - Michaelwww.batemanracing.com Attached Images
Reply:i'm going to be welding up some AL cylinder heads (squish combustion chambers ) and have been reading a bit into it. first off, are you preheating? that will make up for a lower powered machine quite a bit. it looks like you have a pretty large torch. i would switch to a shorter back cap and maybe even a smaller torch in general. also, i hope you have a WC torch. AL will make your torch HOT. my $0.02
Reply:Oh yes - definitely preheating.  Makes a big difference, but not enough.I guess I should have put something else in there for scale - the wp20 (water cooled) torch with a #5 cup is pretty small.  These are 175cc twin cylinder heads - they're less than 10 inches across total.  I'm needing to weld about 2" into the port, at which point it is only 1/2" tall.  At it's largest point it's only about 1.5" around.  I've got short back caps, and button back caps, but there's going to be no getting a torch body inside that port no matter what.  Someone on the Miller board suggested a MT125 torch which might work with the 45 degree quartz cup, but it'd still be tight and those aren't cheap!  I could see tying up 5-700 bucks in one just to get started with a couple of collets and a couple of cups, etc.  If I can make this a viable service there might be enough dough in it to justify spending on a torch like that.  I'd rather upgrade to a dynasty first though.I'm really interested in hearing about helium mixes and/or DCSP to help with my power issue - I think I can reach enough to do what I want if I can get a bit more effective power to the metal.I did think about trying to cut off a cup at an angle to see if I could "shoot slightly sideways" - anyone ever try that?Michael
Reply:Only a sugeestion, and maybe totaly wrong but as you are in such a confined space would it be worth trying to run without a cup, using the port as the cup so to speak.Like I said just a thought
Reply:Hey bateman147 check out this post were Zap used a modified tungsten to weld in a tight spot. Hope tis helps. Doughttp://www.weldingweb.com/vbb/showthread.php?t=11257
Reply:I've been watching ebay for a super deal on a Smith's mixer like Zapster, but so far no joy. For experimentation purposes I'll probably just get a bottle of helium and a y fitting and try approximate mixing.
Reply:There's only so much you can reach with a welding process.  This is why you see ports epoxied.
Reply:ZAP showed us how to bend the tungsten for some spots...maybe that could work for you... just look for the threadMy Babies: HF Drill pressHF Pipe Bender3   4.5" Black and Decker angle grindersLincoln Electric PROMIG 175that´s it!
Reply:^waldarosa just posted that
Reply:Didn´t see the link! 8Ssry man!My Babies: HF Drill pressHF Pipe Bender3   4.5" Black and Decker angle grindersLincoln Electric PROMIG 175that´s it!
Reply:I have used tungsten sticking out 5 inches with a ceramic tube on to a 1\2" from the end and flooded the area with Arto repair leaks on a tube to sheet on SS hard to use but got the job done