Anyone had any experience with JB weld on engine components? Not moving ones of course. Interested to hear experiences. Am about to experiment myself, apparently this stuff works great. http://jbweldit.com.au/index.php?main_page=product_info&cPath=1&products_id=1
Interesting experience there. I suppose apart from your challenges (damn bugs) it seems to do a relatively good job. I wonder how it would go glueing some parts together though... guess I'll find out!
that stuff tends not to work so well as an adhesive to join parts - that thought depends on what you're joining - so pics and we can potentially help peace out
Well I've got this issue where the top of the valve stem has snapped off, which is essentially the tip of the engine piece that has the oil seal on it. There is no way to reconnect it easily, or weld it, so I am assuming this stuff is my only option. You can see in the pic below the brown bit is the oil seal, but it is still attached to a piece of metal which I call the valve stem (not sure what the technical name is) which is a piece pressfit into the engine. It's highly unlikely I will find a replacement or could do this cost feasibly so a cold weld seems to be my only option. It's not a moving part itself though, I don't think the valve would ever impact it heavily and I doubt it will get too hot so I think it's low risk.
if you've got the engine out and the head off already just replace the valve guide - with the oil impregnation into the rough surface of that metal you'll never get it totally clean for a good bond, then if a gap opens oil will go down into the cylinder causing smoke very very likely that size valve guide is used on lots and lots of engines - a good cylinder head reco place will be able to cut a longer blank one down to length if need be and ream it to perfect clearance peace out
Hmm. I may have to look into that, but am really trying to keep cost down. I have the JB weld now so I'll see how it holds up, the oil doesn't seem to have penetrated too deeply into the surface but I'll give it a soak and hope for the best. If it gets smokey I'll just pull the engine off again I suppose. Gotta be easier the second time around!
i would not put my money on it holding. there is heat and thrust on it.a new valve guide pressed in is the way to go.
11115-11D70 part number for your valve guide http://classicmotorcycles.about.com/od/technicaltips/ss/Replacing-Motorcycle-Valve-Guides.htm small article on replacing a valve guide. trevor jordon motorcycles has the guide for $16.50 if you could change yourself it wouldn't be all that dear ( a decent mechanic who specializes in head work could do it cheapish as well i reckon). I think you may as well do it properly instead of tearing down the engine again when it lets go.
I recently replaced the full set of 16 valve guides on a car engine - simple task - removed them using a pneumatic hammer - small one with an allen key bolt through the valve guide - the cavity in the head of the bolt keeps the point of the hammer bit centred. fitting new ones it's the reverse, though I had cut a slug of aluminium to the appropriate thickness with a hole so that the guides went in to the appropriate depth. fitting is a trick, heat the cylinder head in the oven for 45 minutes - 1 hour 150 degrees centrigade for memory, meanwhile the valve guides had been chilling in the freezer - it took two goes to get the set of 16 refitted as the cooling during fitting made them more difficult... so the moral of the whole far too long story - get the valve guide replaced - it's not a big deal, but JB weld or any other adhesive isn't going to manage to keep those two halves together... peace out
I'm not so sure. It's rated to 550 deg F (287 deg C) with a strength of 3960 PSI. It's not like it's getting impacted by the engine and I'm not sure that particular component would get that hot. At worst, I'd expect the component to get to around 250 deg F (120 deg C) which is probably generous at best. Thoughts? I really think it's worth a go. Tearing down the engine again isn't my primary concern at the moment - it's cash.
I think jb weld is good for covering a hole in a case. But sticking a piece that has constant friction and heat near it might prove to challenging for it.
Try it and see what happens. Worst is you will have to fix it again. I would use some general purpose thinners and blast with air to clean the bits before joining to get all the oil off.
I'm no expert at all though, did you factor in the vibration caused by 18000rpm? Your engine is only as strong as it's weakest link. Could be worth a try though so I am now sitting on the fence.
I dunno guys I've read all these stories of this stuff being pretty super. Vibration, harsh environments blah blah blah. So I'm assuming this won't be a massive task for it. Like any epoxy it will soften over time but I don't think I am putting it in a massively high stressed situation. Suppose all I can do is try it and if it doesn't work it's not like my engine will blow up, just a leaky valve.
hate to see you drop a valve.personally i would err on the safe side and replace.what does a new head gasket cost?
Don't think I'll need a new one considering this one is made of thin metal and is not one of the compression style gaskets.
