Cast exhaust with Fluxcore

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This is the exhaust from my 96 Toyota Tacoma. I welded it without pre-heating and only a propane torch to keep it from stress cracking after welding. I thought some would like to hear about this. Attached ImagesMiller Thunderbolt 225Millermatic 130 XPLincoln HD 100 Forney C-5bt Arc welderPlasma Cutter Gianteach Cut40ACent Machinery Bandsaw Cent Machinery 16Speed Drill PressChicago Electric 130amp tig/90 ArcHobart 190 Mig spoolgun ready
Reply:As you can see it was cracked all the way around except for one inch.Miller Thunderbolt 225Millermatic 130 XPLincoln HD 100 Forney C-5bt Arc welderPlasma Cutter Gianteach Cut40ACent Machinery Bandsaw Cent Machinery 16Speed Drill PressChicago Electric 130amp tig/90 ArcHobart 190 Mig spoolgun ready
Reply:here is one that i did the same way... it is off of an old 78 Dodge Aspen with a Mopar Slant-6. it was cracked all the way around as shown in the picture and actually welded up quite nicely. it was welded on multiple heat settings (Hottest for the root and hot-passes, coldest for the cap for good appearance and blend-in to the cast). NR-211MP in my LE 100HD.(yes, that is JB weld around the joint... no, it wasn't me).here's what we do:tack it all together, all the way around to make sure that all is aligned and well-fitted:we make a j-groove on each side with the grinding wheel. this will allow us to get full penetration into each piece. this groove is only on 25% of the intended weld joint. it follows the crack on one side of the piece:we then lay a root pass to join the two pieces back together and then fill the rest of the void with more filler. after the joint has been filled, we turn the heat down so the puddle will stop pulling in the cast iron and creating massive undercuts. this is strictly for aesthetics:i don't have any pictures of the joints after the flux was removed, but they didn't look quite as nice as ST's welds.ST, i see little to no porosity and/or undercut. is that cast iron or cast steel?Later,Andy
Reply:Surface exhaust manifolds after repairHere's some suggestions from the school of hard knocks,after a good 1,000 CI repairs:1-grind the skin-off around the crack area for better fusion of the cover passes. Really 'cooked', black, heavily grained areas in the crack area; which if ground out--leave very little shiny CI to weld to---I pass on. Time for another manifold. They are consumable parts.2-grind or carbide burr to groove/bevel the cracks-as Andy did3-tacking up, first to hold alignment;  then beveling/grooving the cracks helps--as Andy did!4-for some really tweaked, out-of-flat manifolds, consider bolting them down--not clamping to a heavy strongback of very stout angle, etc.--to help keep the gasket surface as flat as possible--prior to surfacing5-Establishing a ground/machined flat surface gasket flange surface--prior to installation, is what professional engine rebuild shops do--to prevent leakage and minimize stress on the manifold, when torqueing it back down. A repair welded manifold is even more prone to subsequent cracking.Many--undamaged manifolds will spring, out of flat on the gasket flange, when they are removed from the vehicle.A damaged manifold, is most likely--not flat. I check this, in front of customer, before accepting job. Flat means--dead flat--no daylight. After repair, the manifold is surfaced by an engine shop, 3 doors down from me. I insist on surfacing.(some manifolds are difficult to impossible to surface, due to their design)A 6 cylinder manifold, needs to be surfaced with the intake mounted to it--to keep things lined up---BTW.After surfacing, the inner and outer flange corners, port openings, are chamfered, to get rid of that sharp edgeBlackbird
Reply:Best way to fix the slant 6 is to get somthing else.
Reply:STwelder, I work for Toyota and they read a memo to us a couple weeks ago saying the 95' to 2000 Tacoma had "higher than average" frame failures. They are going to offer owners a free fix or buy the truck back for 1 and half the book value. Have you recieved a notice yet and wondered what you are going to do.
Reply:aczeller it is cast iron. And I first tacked it in the middle of the break/ opposite of the side still holding it together. First tack and propane torch, I thought well probably don't need the propane. So second tack didnt use propane torch, well while cooling it went ping and split the tack. Thats one of the reasons that I didnt take pictures of the prep work, I thought it would fail as I had been told it was a hard job for experienced welders. Well after the first stayed with the propane torch help, I said here we go. Welded it all in three beads. End of break and then either side to side that was not broke, with heat from propane torch about an inch or inch and a half from the weld to pull the heat away from the weld area. And I must say it worked nicely. And didn't take long, about 15 min of heat after the welds and done. Ohh welder is a LE 100 settings were B on heat and 2 on wire feed and wire is .035 flux core E71TGS.Last edited by STwelder; 05-26-2008 at 10:04 PM.Reason: left out welder settingsMiller Thunderbolt 225Millermatic 130 XPLincoln HD 100 Forney C-5bt Arc welderPlasma Cutter Gianteach Cut40ACent Machinery Bandsaw Cent Machinery 16Speed Drill PressChicago Electric 130amp tig/90 ArcHobart 190 Mig spoolgun ready
Reply:weekender No I haven't received anything from Toyota about my truck yet, and I am the second owner of the truck 13,000 miles when I bought it. Although a friend of my did get the letter you are referring to. He didn't mention a free fix though, just that a one and a half blue book payout. And that Toyota really wants these trucks off the road. I will keep you posted if I do receive such a letter.Miller Thunderbolt 225Millermatic 130 XPLincoln HD 100 Forney C-5bt Arc welderPlasma Cutter Gianteach Cut40ACent Machinery Bandsaw Cent Machinery 16Speed Drill PressChicago Electric 130amp tig/90 ArcHobart 190 Mig spoolgun ready
Reply:Interesting how malleable the Toyota manifold seems, compared to the Chrysler, Toyota probably spiked the melt with a Ford Falcon or two. Andy - Most visible in pics 3 and 5, the reason those bolts snapped is because they are not through bolts. The nuts on the bottom are only to retain the bracket, the bolts are also threaded into the manifold. The nuts have to be pulled first, otherwise they act like jamb nuts, preventing the bolt from turning out of the manifold. The broken bolts will have to be removed from the top, because of their shoulder. That job will deserve a thread all to itself. Curious - Did either of these manifolds seem to show extensive  post-heat cool down time? Last edited by denrep; 05-26-2008 at 10:16 PM.
Reply:Originally Posted by weekenderSTwelder, I work for Toyota and they read a memo to us a couple weeks ago saying the 95' to 2000 Tacoma had "higher than average" frame failures. They are going to offer owners a free fix or buy the truck back for 1 and half the book value. Have you recieved a notice yet and wondered what you are going to do.
Reply:Originally Posted by denrepAndy - Most visible in pics 3 and 5, the reason those bolts snapped is because they are not through bolts. The nuts on the bottom are only to retain the bracket, the bolts are also threaded into the manifold. The nuts have to be pulled first, otherwise they act like jamb nuts, preventing the bolt from turning out of the manifold. The broken bolts will have to be removed from the top, because of their shoulder. That job will deserve a thread all to itself. Curious - Did either of these manifolds seem to show extensive  post-heat cool down time?