Are Heli Coils safe in a Flywheel???

I just picked up a hard to find Olds flywheel off of Ebay and just open the box to find that someone has installed HeliCoils in every hole. Is this a safety concern or normal practice??? Any input would be appreciated. Thanks!

 

I would say ANY repair on a flywheel is not safe,,but thats me

 

yep no go!

 

So rotate it 60 degrees and drill new ones.

 

I'm trying to figure out why would there be an issue? The helicoil is just holding an outward pull of the bolt, not a shear strength fighting tourque. I don't see an issue with it, and other than it being "different", WHY would there be an issue?

 

not sure what all of that means ,,but the forces and heat etc ,,not to mention the spinning m*** of a flywheel,,toss it and get another,,Hell we've all seen what a non repaired clutch can do when it fails,,to me just seem like your asking for trouble

 

I can't imagine it will hurt much if used on a normal hot rod for the the street and show as long as it is straight and true with no other real damage. But, if you plan to race it, you probably should be using a proper safety bellhousing anyway and probably should just get a non damaged one. It is a flywheel that can't be seen anyway, so better to use good new parts for something like that in a racing situation.

 

What is the max torque for helicoil? If they are engineered to take the torque of the fly wheel bolts why would they not be OK? The centrifical force of the fly wheel should not have an effect, right.
Jim

 

If the Helicoils were installed correctly,
I would run it on the street without hesitation.


Is the flywheel steel or Aluminum ?

 

Exactly my thoughts. I want to know why EXACTLY from the people that say no.

 

piece of mind is worth more to me than saving a few bucks. I would toss it

 

Ok,,why would you not just make a slightly larger hole and tap it??

and well I see no reason to defend my statement,,he can do whatever he wants,,myself I see no reason to take the risk,,I like me feet and legs right where the are

 

Absolutely. We still have machine shops here in America don't we?

 

You torque them to 35 ft-lbs. If the helicoil can do that, then why not use it? I'd make sure the helicoils were installed properly.

 

We use helicoils at the dealership for head studs and other heavy duty stuff all the time. The helicoil will be just fine as long as they are put in correctly. I ALWAYS use thread locker on the coil to part face for security measures.

 

And you don't HAVE to, but when the guy is asking for mechanical reasons not to run it, should be ABLE to.

 

Seems like a flywheel would be pretty thin for a heli-coil, aren't most of them stamped out of sheetmeteal?

 

This is a manual/clutch flywheel we are talking about correct?

 

no,,I have seen them used on many parts ,from what I have seen with flywheels going a stray ,,on such an old piece ,,I would avoid it.

Thing is if he posted a frined got a flywheel that was heli-coiled and it blew up on him,,most of you would be saying,,well he's an *** for not getting a good one so,,lol

I would go with teh 60 degree idea,,plus also
you have NO idea who did the work ?? you wanna take the chnace it was'nt done right ???

 

Isn't the helicoil simply a larger set of threads in the softer material?? I think it increases the strength of the hold in the aluminum. Helicoils are routinely used in all sizes of threads including high torque/high load situations, and I think some racers often put them into all aluminum casting threads on racecars as part of thorough preparation of new parts for a season of racing.

 

You are thinking flexplate.

 

And the seller didn't mention that EVERY hole was redone with a helicoil? I don't know enough to tell you if that's safe or not, but I gotta wonder what the hell happened to it that all the holes got stripped?

 

Flywheel, not flexplate, oops.

 

don't know about the safety aspect but I'd raise hell with the seller for not disclosing that in the listing

 

If its a rare Olds Flywheel it would seem to me its gonna be steel..and again,,your putting faith in unknown workmanship and off of ebay at that

and yes he says that EVERY hole has been done that way,,so more over you have to ask how the hell the wheel got that way ?? I would also question the integrity of the wheel

 

Yes Bruce, they are. Most times helicoils test HIGHER then the smaller original thread in the parent metal, even in steel.

I just was having fun at the answers given on paranoia rather than fact.

 

I know VW guys heli-coil all the holes in magnesium engine cases.

 

Paranoia ,,wow. I'm glad you would be so trusting

 

helicoils I've messed with put the threads right back to the original size, not bigger.

You just drill out the hole & tap threads if you wanted a threaded bigger hole.

Carl Haga

 

Uh, don't they put steel thread inserts into all kinds of aluminum engine and transmission parts?