What strength threadlocker?

[Wollfen]

I am hoping to start assembling the 440 I have here in the next couple of weeks and I don't remember what strength threadlocker I used to use on the rod bolt threads. I used to use a Permatex blue color, but which one escapes me now. Anyone care to offer advice?

 

[jct]

don't use red thread locker you'll never get it out

 

[C Body Bob]

If you got to use thread locker blue is the one

 

[Big_John]

Blue is fine, but I've used red with no issues too.

 

[Wollfen]

Okay thanks guys, I had it in my mind there was different strengths of threadlocker within the blue range for some reason, i know that is true of Loctite red.

 

[commando1]

I use red for the "set it and forget it" bolts, blue for and bolts that should be retorqued after break-in.

 

[Fury Pursuit]

I am hoping to start assembling the 440 I have here in the next couple of weeks and I don't remember what strength threadlocker I used to use on the rod bolt threads. I used to use a Permatex blue color, but which one escapes me now. Anyone care to offer advice?

The Con-rod bolts are usually torqued from 45-55 ft lbs. 220 (blue) Loctite is rated to 110 ft lbs and up to 300 degrees if I believe.

Make sure you use the Loctite primer before you use the thread sealer. Loctite doesn't always cure on certain substrates/surfaces (e.g. cadmium, stainless steel etc) without the use of the primer. Ask me how I know.

 

[Fratzog]

Is thread locker even necessary if you are torquing everything to specs?

 

[Big_John]

Is thread locker even necessary if you are torquing everything to specs?

IMHO, yes it is necessary to use Loctite on rod bolts.

Or you can look at it this way... It does no harm at all to use and the gains are it keeps the rod nuts in place. A loose rod bolt can (and usually does) cause a catastrophic failure of the rotating assembly, most likely taking out the entire engine.

 

[butchr66]

If you use locktite make sure you get all the oil off the threads and use the locktite primer

 

[1970cat]

never heard of using loctite, but like was stated above, red is the high temp. i have my doubts that it would hold up though.

 

[Yatzee]

Trust me. As a millwright for 32 years I can tell you that using thread locker is next to useless. At 175 degrees thread locker locks no more. You release it by warming the bolt/nut it is securing rather than damaging them. Rod and main bearing bolt torques are stated either dry or wet but not with thread locker.

 

[Wollfen]

Hmm, that's interesting Yatzee, I have seen many shops use threadlocker on rod bolts. You have me wondering now. I started using it after seeing at least three engines with nuts that have come undone after rebuilds. Mind you I haven't had it happen to me yet and I don't want it to. Regarding the nuts and bolts themselves, I always put in brand new ones. (ARP)

 

[butchr66]

Hmm, that's interesting Yatzee, I have seen many shops use threadlocker on rod bolts. You have me wondering now. I started using it after seeing at least three engines with nuts that have come undone after rebuilds. Mind you I haven't had it happen to me yet and I don't want it to. Regarding the nuts and bolts themselves, I always put in brand new ones. (ARP)

Yes use new studs/nuts/bolts etc and alittle oil on super clean and pristine threads. I work with all the different locktites through my job and basically anything that's crucial shouldn't have locktite on it. If you use it, you won't get a true torque reading and it will form a barrier between the contact surfaces of the threads.

 

[bluefury361]

Locktite is a good thing and won't effect torque spec's. Generally use red when threading into steel threads, blue when threading into aluminum.

 

[Yatzee]

If you use ARP's you'll know that there is a procedure to torquing their bolts and they even include the thread lube to ensure they are torqued properly. They don't use thread locker or even mention it.