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I was asked if someone could weld up a spark plug hole in a aluminum motorcycle cast head. My concern was taking the temper out of the head due to the added heat of welding up the hole. Would he have to re heat treat the head? or temper it? I was thinking that welding it would make that area soft and not be as stable after it was welded. What is the best way to weld up a spark plug hole and not hurt the head?---No good deed goes unpunished---
Reply:You are not going to hurt the head. But a better choice instead of welding is to ream the hole and put a helicoil in it. Any auto machine shop or motorcycle repair shop has them. Stripping the threads is a common problem.If you are determined to weld it, ream the hole and fill with 5356. 4043 is ok, but a bit soft.You just don't want to overheat the head. So get it done fast or do it in steps.
Reply:the hole isn't stripped, he wants to re locate the plug and reshape the dome. I personally think it's a bad idea, but was concerned about the heat and possible warpage of the head. Will welding it make the dome of the head unstable?---No good deed goes unpunished---
Reply:What make/model head, has anyone else done it on that make/model before, and what exactly does he have in mind?Sounds like he doesn't know what he's doing, which is a good reason to either use a throwaway head first or not to do it.
Reply:Actually, I'm not sure as of yet. I'm on another forum and this guy is writing about doing it. I don't think that welding up a head without proper heat treatment after is a good idea. Even if he held the head flat while he welded it he would still have a weak spot in the dome.---No good deed goes unpunished---
Reply:Originally Posted by shovelonIf you are determined to weld it, ream the hole and fill with 5356. 4043 is ok, but a bit soft.
Reply:Originally Posted by BoostinjdmBad info. 5356 is not well suited to service temps over 150 F. 4043 is a common ch oice, but there may be an even better filler out there depending on the make up of the head.
Reply:Originally Posted by shovelonIn most situations I would agree with you but in this case 4043 makes for ****ty threads in cast alum. And no I don't have supporting documentation to back up my claim.
Reply:I would imagine its a 2 stroke and hes trying to tune it. In my experience your better off reshaping the head in a lather or mill. However, weld the hole no biggie. Good luck with the tuning.
Reply:Originally Posted by BoostinjdmI know 4043 makes ****ty threads, but he is filling the hole and moving the spark plug. A hot head is the last place I would want to use a filler not recommended for temps over 150 F. Even a water cooled head will run hotter than that.
Reply:I would make up an alum plug with with 14mmx1.25" threads thread it in and plug weld on the inside much less heat easy to do .Thats my 2¢VLast edited by Vinnie; 06-14-2011 at 06:56 PM.
Reply:Hey guys,My opinion is that Vinnie has the best solution so far.... definitely worth the 2c.DennyComplete Welding/Machine/Fab. ShopMobile UnitFinally retired*Moderator*"A man's word is his honor...without honor there is nothing.""Words are like bullets.... Once they leave your muzzle, you cannot get them back."
Reply:Originally Posted by yorkiepapHey guys,My opinion is that Vinnie has the best solution so far.... definitely worth the 2c.Denny
Reply:Originally Posted by farmallWhat make/model head, has anyone else done it on that make/model before, and what exactly does he have in mind?Sounds like he doesn't know what he's doing, which is a good reason to either use a throwaway head first or not to do it.
Reply:Sorry double post.AWS certified welding inspectorAWS certified welder
Reply:That is what I like about this forum. You get to pick many brains and find some really good solutions. Keep em coming Gordie -- "I believe you understand what you think I said, but I'm not sure you realize that what you heard is not what I meant."
Reply:Thanks guys for all of the great info. I appreciate it.---No good deed goes unpunished--- |
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发表于 2021-9-1 00:14:23