Hey guys, my passenger side manifold cracked on my '65 Skylark 300. Anybody ever get a cracked manifold fixed? What other manifolds fit a 300? 215, 340? Any suggestions would be good, I hate having my cars laid up and I'm always on a death march to get them fixed when they break. I don't sleep or eat until I fix it. :grin: Thanks! Aaron
you could braze the part using an oxy-accetline torch. I did this to an intake manifold. what you do is drill a hole at either end of the crack. to in theory stop the crack. (it does help though you may need to use a good size of bit though i used about 1/8th inch. and then possably grind a v groove along the crack. you want to evenly heat the area to avoid growing the crack. put a decent amount of flux on the surface to be brazed and heat the metal red hot. and lay a thin bead/film of brazing rod along the crack. Nate
precausions... it may warp the manifold. it depends on what portion is cracked is a big deal with the warping. although if its a thick location of the part with the crack either you grind the V groove really deep and go from there (although thats not recommended.) or you may need a new manifold. I did it on my intake but right where the heat cross over goes to the other side. the opening had caved in on one side and I had to fill that and fix two cracks. then i filed it down to become smooth again. I never milled it flush but more or less did the glass plate test (with a feeler gage) and it came out really well and dosen't leak anything. when brazing one of the cracks i had introduced another one because i didnt spend enough time preheating the surrounding area and had to go back and seal that one. do you have pictures of the area cracked? it maybe easier to just find another manifold though. nate
there is a thread somewhere on this board that goes into detail on the options for repairing exhaust manifolds...it actually goes way over my head in spots...for even more mind-boggling discussion of welding for cast-iron, go to google.com and search groups for "exhaust manifold repair" but my two cents worth is to start looking in the yards and on ebay for a replacement manifold...mine cracked and i found a nice set off a 70 buick dauntless 350 (the buick motor that went in jeep wagoneers for a couple years), bolted right on... good luck, scott
yea generally to weld cast iron you need to heat the entire piece red hot in an oven. along with a bunch of other problems. nate
While we are on the topic of exhaust manifold welding, I need to weld a washer to replace a portion of the head pipe conector flange that cracked several months ago. Am I ok just to quickly tack the washer to the manifold????
Hey guys, It's a moot point now, I found a screaming deal on a pair up at an old junkyard off of a '67 Special. The car's up and running again! I climbed through this junkyard full of old cars, found a '67 Lark without a motor, a '66 Lesabre missing only the right manifold, and a '65 Lark sedan with a cracked manifold. I finally found the Special at a later model junkyard, but one of the employees loves Skylarks, so I got the pair for a great price! Thanks for your replies...took the original to the weld shop and it was beyond repair. Aaron
Aaron, These manifolds are famous for cracking, usually at the ear/manifold junction. A major contributor is over torquing the mountings. Adhere to the factory spec and see if you can get a good seal without gaskets. These came from the factoy without gaskets and it makes getting proper torque on the mounts difficult. Cheers, John
Mine wasn't cracked on the ears..it was cracked all over!!! I torqued mine without a gasket to 14 ft. lbs. I don't hear any major leaks, and it's been on there for a couple of weeks. I'm hearing that these manifolds are weak, nice design but weak. Thanks for the tip John! Aaron