14 replies to this topic

[Se7enS1ns]

Ok im starting to panic a bit now, ive just finished an engine rebuild (hence all my other posts worrying about stuff) and just realised i didnt use threadlock anywhere, apart from the flywheel bolt and crank pulley bolt. Should i have done?

Please say no.

[*DJH*]

It would've helped

[Big_Adam]

Alot of the stuff in the A-series engine if it's not meant to move then it has locktabs.

[Se7enS1ns]

Ah bum. Where in particular? Dont say big end nuts. Do NOT say big end nuts!!

[yorkshirechris]

Big end nuts

[Se7enS1ns]

Big end nuts

Haha you're funny. But im funnier. You know why i'm funnier? because i know where you live, ive been round your house. Twice. You have been warned boy.

[Ethel]

I think the good ol' A was designed without a second thought about loctite so it's more of a belt 'n braces issue really.

Flanged nuts such as on the big ends preload the threads much like a spring washer would - shouldn't unwind in a hurry.

[Se7enS1ns]

Phew!

[Turbo Nick]

i've never threadlocked anything in my engines and nothings fallen out so far...

as long as they're torqued up they should be fine dude.

[Se7enS1ns]

Yeh should all be fine, like i say ive done the flywheel bolt so that will / should be fine.
Just cacking myself a bit as it my first FULL engine build, spending a fair old chunk of cash in the process. Im certain somethings gonna bite me in the ass!

[jayare]

Only place I've used threadlock is on the front pulley bolt (I'm using this one: http://www.minispare....aspx?pid=37968 It has much longer threaded section, and as you can't use a locktab, you have to use threadlock). The engine's been together for nearly 40K now, and nothing's fallen off yet!

JR

[Sprocket]

You should NEVER use thread lock on big end nuts, Mains bolts or Head studs and nuts. It would be a sure way of making the engine fall apart!!!!

[Se7enS1ns]

Well yeh i thought that too, as from memory im sure my old man telling me that using threadlock on torqued nuts can cause the compound to start "curing" due to friction heat, resulting in incorrectly torqued nuts / bolts, even though the torque has been gained at the wrench. Or something along those lines.

[Dan]

It means you'll be over stretching them due to the reduction in surface friction if you apply dry torque values alone. Threadlock doesn't go off with heat. They'll be more likely to break due to being over stretched and the Locktite by itself won't hold. A-series engines are much older than Locktite though.

Have you used new locktabs or new shouldered bolts or Nylocks in the relevant places? Or new pre-encapsulated bolts (like the oil pump bolts that come with special thread lock on them already?) If you didn't use the clutch locktabs you should have used thread lock in the clutch assembly IMHO (and M.E.D. / Morspeed's).

Threadlock on the flywheel bolt? I wouldn't myself but you've done it now. It's just that this is quite a high torque bolt and could easily be over stretched as a result. Maybe others always lock this bolt but I don't see the need, it's the taper that holds the flywheel once it's set.

Edited by Dan, 28 September 2007 - 09:38 AM.

[Se7enS1ns]

Thanks Dan.

Have you used new locktabs or new shouldered bolts or Nylocks in the relevant places? Or new pre-encapsulated bolts (like the oil pump bolts that come with special thread lock on them already?) If you didn't use the clutch locktabs you should have used thread lock in the clutch assembly IMHO (and M.E.D. / Morspeed's).

Erm no. Ive used new lockwashers for the flywheel bolt, crank pulley bolt, and cam gear retaining nut. Everything else i just used what came off, as i wasnt aware new shouldered bolts should be used. I dont recall seeing any nylock nuts anywhere? When you say clutch locktabs, where do you mean exactly?

Threadlock on the flywheel bolt?

Yeah. I know a lot dont, but i always have. This is my first full engine build, from a freshly machined bare block, but ive been assembling short engines for a few years now with no major disasters. Ive always used threadlock on the flywheel bolt and taken the time to lap the tapers. My friend never does. He's had two fall off to date, destroying the flyhweel and crank. Im going to carry using it.

Thanks for responses all, i like these informative posts more than the pedantic/sarcastic ones