heel2toe

iTrader: (41)

Wanted to create around this topic bc this issue is driving me insane. Since rebuilding my motor it's been one thing after the next with bolts backing out and causing mechanical failures because of it. In most cases where applicable fasteners are torqued to spec yet still have worked their way outward. Others I may have left a little loose like the valve cover bolts for example as in my dozen years of ownership those just need to be snug but not anymore as they back right out!

Since the rebuild a few noteworthy changes were made which is clearly contributing to my failures
- no balance shafts
- stiffer engine mounts
- more revs

That being said I'm not the first person to run a built motor in an evo nor will I be the last so its not like I'm in uncharted waters here.

One other noteworthy point is I live in MA and the car used to be driven year round so needless to say over the years antizeize and myself have become quite good friends since rust seized fasteners also sucks. Im thinking moving forward I shouldnt be using antiseize?

Have any of you folks run into similar issues? Are you using loctite on most fasteners or safety wire or what have you found worked well? Also what fasteners are you doing this for? It it just mission critical components? Id imagine depending on the sanctioning body certain things like oil drain plugs steering components brakes etc basically anything safety related must be secured?

Im still ironing out the kinks with my build but I've literally broken the car every single event this season due to some sort of dumb failure to the point that me showing up in my car is basically a joke. Please help me

Ayoustin

iTrader: (2)

What has loosened up on you?

Torquing everything to spec won't necessarily work on a racecar. Except for critical engine components I over torque just about everything on my car. Antisieze is something of a lubricant so using it on a fastener that calls for dry threads will ultimately leave you with a lower clamping force if the fastener displaces the same amount of threads both times. Hence why I over torque just about everything.

kyoo

iTrader: (29)

loctite red?

heel2toe

iTrader: (41)

So you bring up an interesting point about overtorquing but if youre overtorquing a fastener to the point that it stretches then that isnt exactly good by any means. Now knowing where that yield point is however is another story. I guess what im tyring to say or ask is would overtorquing even be considered a good thing as it also seems risky. But to that end say you have 2 identical fasteners one torqued dry and the other with a lubricant like antizeize. If you torque them to the same spec the one with lubricant in theory would actually be overtorqued relative to the one that went in dry. So if anything by me using antiseize I think Im already overtorquing if that makes sense?

Things that have come loose since rebuild:
-valve cover bolts
-north south bar in rear and one bolt in front also worked its way loose
-power steering pump 3 bottom bolts backed out yesterday and flung my acc belt off bc it
-oh heres a good one my v band clamp from o2 housing to donwpipe loosened up!
-also found some random m6x1.0 bolt last night sitting on my trans near the salve cylinder...not sure where he belongs at the moment haha!

Ayoustin

iTrader: (2)

Red loctite is always a no no. Its intention is to be used on bolts that will never be loosened again. The only way to remove bolts with red loctite without damaging the threads is to heat them with a torch.

@heel2toe don't confuse clamping force with torque. They're similar but not the same. Clamping force vs torque will vary depending on the condition of the threads (are they dirty, clean, lubed, dry, etc.). Clamping force vs thread displacement will always remain constant.

This is why the head and main bolt torque specs call out a torque-to-angle (TTA). Having a bolt displace a certain angle means that even if one bolt is dirty and dry, but another is clean and lubricated they will both achieve near identical clamping forces because they will both be physically displacing the same amount of threads, yet the torque required to get them to that same angle will be very different.

So no, you're not over torquing the fasteners by using a lubricant. Nor does over torquing a bolt mean you're taking it past its yield point. Torque to yield fasteners are pretty rare and to get a bolt to elongate without shearing is a science, so I wouldn't worry about elongating any of your bolts, you'll end up shearing them before you'd notice they've lengthened, and usually you can tell before you're going to shear a bolt.

As to those specific bolts, my valve cover bolts have come loose before, I've found I have to make 3 passes or so on all of them to make sure the gasket is compressed properly and evenly. The north south bar bolts are beefy, don't be afraid to overtorque them. If spec is 60-70 to go to 80-90, I usually just throw a breaker bar on those guys and keep turning until it's a challenge (which is probably well north of 90). And as for the power steering pump I've torqued those to spec before and had one loosen up, so now I over torque them an extra 5-10lb/fit but I also don't use anti seize on engine components, just chassis and suspension stuff.

heel2toe

iTrader: (41)

Yeah i will not be using red loctite for the reasons mentioned but do plan to give blue a shot with some of these.

Great explanation of torque vs clamping force and you are correct I was most certainly confusing them as one in the same. Just thought it was worth mentioning bc I didn't feel I was undertorquing and if anything was indeed going over. But perhaps not and also to your point guess my fear of yielding a fastener is silly and unjustified.

Since overtorquing have you had those bolts back out? Im curious if I start with going a little tighter or just go straight to blue on some of those.

LetsGetThisDone

iTrader: (1)

Lol @ torque specs. Basically everything gets MF tight except for critical engine fasteners.

Ayoustin

iTrader: (2)

Just go tighter, you won't hurt anything unless you start torquing stuff with an unreasonably long bar. I haven't had anything back out on me except a couple occasions where I straight up forgot to torque bolts lol

heel2toe

iTrader: (41)

Lol tighter it is! I'll give that a shot and hope for the best. The VC bolts I just refuse to like super crank down bc I fear ripping the gasket. I just got new wavy washers for the VC so im hoping that will help with those from backing out.

Racing again Sat and would be amazing if I went the entire day without wrenching. Not going to hold my breath but seriously that'll be the day.

Dallas J

iTrader: (1)

On things with higher bolt loads like turbo bolts, if youre having them back out try Nord-lock washers. They are epic at preventing bolts from moving. My old car would need turbo bolts tightened constantly for a span of years. I broke several bolts becuase of it too. We switched to Nord-lock and never once did one come out.

heel2toe

iTrader: (41)

Knock on wood but my current turbo bolts seem OK. My kit came with new hardware and not sure if they're legit Nord-Lock but they have the ridges or teeth or whatever to lock into eachother. I did notice and realized I forgot to mention but the bolts holding my CHRA together on my EFR are showing some signs of exhaust leak. I checked them but didnt move but goes without saying that those are probably starting to back off. Not sure if I could use Nord-Locks there but the CHRA came with ARPs predrilled for safety wire so maybe ill just wire those bc I can pull the entire thing as an assembly anyway.

LetsGetThisDone

iTrader: (1)

Nord locks are the ****.

nollij

iTrader: (21)

Got a pile of nord-locks. No probs no mo. All heat cycle bits and a few suspension/drivetrain bits get them.

You can really only re-use them once or twice though.

Ayoustin

iTrader: (2)

On the CHRA safety wire will work fine. On other stuff that sees heat cycles nord locks work great to reiterate what others have said. I just found a bunch of them on my bike today haha.

pshooter

iTrader: (8)

I did a brief stint with no balance shafts on a road course car. Pretty much any fastener was fair game to loosen.
They went back in.

Shoe