helicoiling

[djr]

hi hope someone can help i put a topic on last week as to the the setting of the cylinder head bolts on my fjr that i have just bought

the bike had a head gasket fault i have just stripped the head of the bike and found two of the bolts have stripped the threads can anybody

tell me if helicoiling would be ok or should i just scrap the engine and find a trasplant engine

thanks for all your help from my last listing

dave

sorry

its two of the head bolts that have stripped the threads from the block

 

[Andyfjr]

Time-sert seems to be a better thread repair system. There are UK suppliers, I have just checked the interweb

 

[Checkswrecks]

It should be possible. A photo would help us understand which location. On thread fixes this critical don't hesitate to go to a machine shop.

 

[djr]

It should be possible. A photo would help us understand which location. On thread fixes this critical don't hesitate to go to a machine shop.

sorry its two of the cylinder head bolts that have stripped the threads from the engine block

 

[charismaticmegafauna]

On thread fixes this critical don't hesitate to go to a machine shop.

Agreed: machine shops are the experts at solving these kinds of problems -- it's, almost, their stock in trade.

A Helicoil is an excellent thread repair device -- especially, where it may be an only one-time, or infrequent, use. They're typically not much longer in length than the diameter of the bolt (engineering-wise, that's fine) -- but head-bolts, usually, screw into deeper threads.

I'd go with 'Checkswrecks' and consult a machine shop. They may even weld some and re-tap -- or, find or fabricate special thread inserts...?

 

[djr]

On thread fixes this critical don't hesitate to go to a machine shop.

Agreed: machine shops are the experts at solving these kinds of problems -- it's, almost, their stock in trade.

A Helicoil is an excellent thread repair device -- especially, where it may be an only one-time, or infrequent, use. They're typically not much longer in length than the diameter of the bolt (engineering-wise, that's fine) -- but head-bolts, usually, screw into deeper threads.

I'd go with 'Checkswrecks' and consult a machine shop. They may even weld some and re-tap -- or, find or fabricate special thread inserts...?

thanks for all your replys just dropped the engine of at the machine shop

were they will helicoil the block at a cost of £40 pounds so thanks everybody for you help

 

[mferriter]

thanks for all your replys just dropped the engine of at the machine shop

were they will helicoil the block at a cost of £40 pounds so thanks everybody for you help

Type American, damn it!!

 

[cruppelt]

Good for you, heli-coils are excellent and provide a much stronger connection then the straight aluminum of the block.

And I disagree somewhat with one of the earlier statements, they are MUCH better at taking multiple insertions when compared to the aluminum by itself.

I have used heli-coils with much success for 20 years in hundreds of different custom automation machines. Whenever I use aluminum (usually for the weight), but have possibly multiple screw insertions I will always have screw inserts in there. Even aircraft grade (like 6061-T6) will gall pretty soon and will move from the threaded hole right onto the screw itself. When looking at a softer material (like a 1 or 2 thou series usually used for castings), it will do that even much sooner.

 

[Crash Cash]

I have used heli-coils with much success for 20 years in hundreds of different custom automation machines. Whenever I use aluminum (usually for the weight), but have possibly multiple screw insertions I will always have screw inserts in there. Even aircraft grade (like 6061-T6) will gall pretty soon and will move from the threaded hole right onto the screw itself. When looking at a softer material (like a 1 or 2 thou series usually used for castings), it will do that even much sooner.

OK, so what's the best way to make sure it gets threaded straight? I had that problem with my rear caliper. Do you have any secrets there? Plus what do you think of the knockoffs like Recoil, because finding true-blue Helicoils and their nice insertion tool is like finding unicorns. Even McMaster-Carr no longer sells them.

 

[charismaticmegafauna]

...And I disagree somewhat with one of the earlier statements, they are MUCH better at taking multiple insertions when compared to the aluminum by itself.I have used heli-coils with much success for 20 years in hundreds of different ...

Yes, technically, I agree -- the Helicoil is an excellent device.

Yet, there are many horror stories (in the field) of improper installation and cross-threading, ? with repeated use ending in Helicoil damage, etc.

OK, so what's the best way to make sure it gets threaded straight? I had that problem with ...

 

[cruppelt]

OK, so what's the best way to make sure it gets threaded straight? I had that problem with my rear caliper. Do you have any secrets there? Plus what do you think of the knockoffs like Recoil, because finding true-blue Helicoils and their nice insertion tool is like finding unicorns. Even McMaster-Carr no longer sells them.

So I have to admit that one of the secrets is in how thick the bolt-on part is (with the thru holes in it) - as long as that's thick enough, it can work well as a guide for cutting the threads or for insertion. Another well used option is to use pieces of bar stock over the holes with the full hole pattern in them, and the hole just big enough for the cutter or the heli-coil on the tool to slide in nicely, then use one of the holes to screw the part down. This way you can use the rest of the holes as guides to always go in straight.

I have also cut the threads and put the inserts in by hand without any guides, but the keyword there is to look closely and only keep twisting if the resistance is not way out of whack. Another variable is also to have a good lead-in (chamfer) on the hole, that helps a lot in getting it straight.

Another pointer is that it's very important to use the proper diameter drill for the hole prep. If the drill is too big (or to blunt, which results in a bigger hole as well), it's easier to get the thread cut crookedly, plus you can have big problems inserting the heli-coil properly. That's probably the one big issue I have seen with heli-coils, but it's easily avoided.

I did not know that McMaster is not selling them any longer, that is VERY disappointing. But you can still get the real deal through Amazon directly, or one of the many vendors that sell through them.

I remember using two different off-brands over the years; one seemed just as good as the heli-coil brand, the other had a horrible fit. Sorry, unfortunately I don't know the brands anymore, I always tried to stick with the original brand.

I changed job focus when I started at Tektronix in 2006, I do actual product design now, which means at least hundreds in quantity, often tens of thousands. I haven't had much need anymore since to use heli-coils at work, only for home use. The last instances were one of our lawn mowers, and on my BMW car's engine block.