Flywheel bolts - bolts now replaced but worried about threadlock 'substitute' used

[Split_Pin]

Apologies for the new thread however Google has thrown mixed reviews on this one and wanted the opinion of the trusted brown place before stalling the project to buy new bolts.

At the weekend Brothers Touring and I will be replacing the Corsa engine. Tje new one doesnt have a flywheel, so Im reusing the one on the existing engine.

Haynes says new bolts are needed on refitting and Google suggests that these are stretch items - some say you can reuse these though?

I was wondering what everybody's opinion was on this? A new set is only £6 but I'd rather get the new engine in whrn I habe the assistance available.

[Captain Furious]

For 6 quid I’d probably replace them, but for the sake of getting it in while I have assistance available I wouldn’t worry about re-using them either. I’ve never heard of them being stretch bolts, they’re usually threadlocked though.

[Guest]

If t'were a V10 Lambo engine, then I'd say yes, change them as you don't want it falling off at 12,780 RPM. In a Corsa? Some pound shop Locktrite should suffice

 

* Unless it's a 1.2 12v.. All 17 years olds know these are too powerful to take chances with, and must be put together with the care that 500+ BHP (at the wheels, before Nitrous) deserves.

[spike60]

The Merc commercial yield bolts I fit have a maximum length for refitting but probably cost more than £6. I wouldn't reuse them, a world of shit if snap when running, not so great if you snap one putting it in tho you should feel it yielding before it lets go. A Vx perv may have experience though.

[Split_Pin]

Cheers chaps. I will see how fast I can get them, if not will just reuse with some Stanley superglue I have lying around. Only 54 bhp I suppose!

[fordperv]

Yes change them, a flywheel escaping has a lot of force behind it

[spike60]

It may only have 54bhp but it will have 54bhp flywheel bolts to go with it, GM probably don't use Corvette flywheel bolts in 1.2 Corsa's. Remember if does let go it probably won't be ticking over at the lights.

 

I was building an engine I knew nothing about from a pile of bits and was given the wrong torque and degree for the head bolts, when I twice said it was too much I was told to get on with it. This is how I know you feel them yield when asked too much of although I didn't keep going until I snapped one in the block.

 

As a bit of amusement put "drag car flywheel" into Youtube!

[Split_Pin]

They are dealer only unfortunately so could likely be waiting a number of weeks. Looks like the project will be stalled half way through now, not ideal.

[Split_Pin]

Ordered new bolts from VX, £20 so a bit of a dull yin but theyll be here Tues so not too much of a delay really.

[Bren]

I saw a flywheel that made a bid for freedom in a classic racing mustang.

It left a big dent in the bonnet. It's why some cars have a blanket over the bellhousing.

[dave21478]

I would reuse them with loctite, but I have a "cavalier" attitude to safety.

 

I was at a trackday at knockhill once when someone with a Nova fitted with a C20XE came to a sudden halt on the start-finish straight....his lightened flywheel had let go. It exited forwards through the radiator, slam panel etc and took a substantial chunk out of the tarmac. If it had gone out the other direction the passenger would have been minced.

[Split_Pin]

Im glad I asked - ^^ the seed of doubt had been planted and it just sprouted a big bit of cognitive dissonance there. Esp as I will have the wee man in the car from time to time.

[Split_Pin]

Bit concerned now, fitted the flywheel with the new bolts but I used Stanley super-glue as a 'threadlock' as I thought it would just be the same as Loctite (I now know it is not).

 

Am I going to have to start over again???

[Dave_Q]

Not in my opinion.

 

Few joints really require threadlock, if correct, clean bolts were used and a torque wrench used to tighten them up to the correct torque, they will not self-loosen, with or without threadlock.

 

Did the old bolts appear to have threadlock on? I imagine not.

[dave21478]

I have yet to see a flywheel bolt that DIDNT have threadlock on it. High rpm, high vibration, sudden rpm changes, shock loading......

[sierraman]

I'd put threadlock on them while its all apart. Its designed for situations where there is high vibration or risk of danger if it came loose, axial rods etc.

[Split_Pin]

Not in my opinion.

 

Few joints really require threadlock, if correct, clean bolts were used and a torque wrench used to tighten them up to the correct torque, they will not self-loosen, with or without threadlock.

 

Did the old bolts appear to have threadlock on? I imagine not.

The old bolts had blue stuff on them which looked like threadlock. The new bolts were tightened to the specified torque using a torque wrench with the additional 30 degrees applied.

 

Looking back I have no idea why I didnt just get the right stuff, but I figured that the superglue was the same as 'loctite' but of course that brand makes many products in addition to just glue.

[Dave_Q]

Personally I wouldn't strip it down to put threadlock on, it will be fine.

 

I have replaced a couple of flywheels without using threadlock and had no issues.