Torque specs: wet vs dry...

[ST1100Y]

Interesting read, I'd underestimated the amount of friction loss...

Seems we've to stick to -50% when applying Copper Slip or Anti Seize to any bolt...

Reduced Torque with Lubricated Bolts

Lubrication effect on bolt tension and torque.

www.engineeringtoolbox.com

However is Anti Seize claiming to maintain 75% of the original torque value given

https://www.antiseize.com/PDFs/torque_specifications.pdf

Loctite recommends to reduce the applied torque by 20% when one of their thread-lock liquids is used...

 

[SMSW]

I have a bit of a problem with that page. The text says lightly lubricated bolts get a major reduction in torque if you add more lube? So what is lightly lubricated? Before I believe this I want to see some experiments showing a comparison of 'lightly lubed' to 'lubricated'. While the math is correct in the first example, why not simply show New Torque = lightly lubed x 1.3?

 

[Al st1100]

Over the years of replacing head gaskets never did I dry out the head bolts or the holes they went into. Blew them off but most if not all got oil on them. never had a problem. now the question is does the manufacturer take into account when they give torque specs that oil probably be on the treads. The don't specify dry or slightly oiled

 

[red one]

If you are talking sparkplugs, I use the NGK's or Denso's for the Toyota and never use a lubricant or anti seeze. Torque them by hand till snug.

 

[Tdinova]

Check ngk web site. They used to explain how tight to install tgdplugs. I just installed new one on my ST. They stated , 1st hand tight, then 1/2 turn with a wrench then loosen the plug. Then retighten 1/8 turn .

 

[ST1100Y]

Well, more common maintenance areas...
the bolts holding the brake rotors, the brake calipers or the holder plate for the hub-dampers...
axle clamp bolts...
or folks who like to replace the OEM engine case/cover bolts with stainless...

 

[dwalby]

after 25-30 years of us wrenching on these things if the torque specs needed any "adjustment" due to lubricants we'd probably have heard all about it by now.

I think the only ones I've torqued that actually mattered are the bolts for the cams. Those would seem to qualify as lubricated given the parts are typically bathed in motor oil. I've used the specified torque without any issues, so I see no reason to adjust the torque the next time. I suspect the factory torque spec may have already been adjusted if necessary, since most people aren't going to take the time to remove all oil residue from the bolts and the threads in the head.

 

[RaYzerman]

Regarding cylinder head bolts, check the manual, likely calls for engine oil to be applied before installation.........

 

[rwthomas1]

Here's a fun activity: Get a 1/2" nut and bolt, place nut in good vice. Now try to tighten the bolt at various torque specs by hand, and then check with a torque wrench to see how close you came. We did this is the maintenance shop I run and it was fun, seeing how "calibrated" your arm is. If you have turned a wrench for any length of time you likely have a pretty good feel for any torque spec. We (arbitrarily) chose within 10% by hand, you were an "expert". Would be even better with a beer in hand.

I was told to use this stuff on aircraft engine spark plugs, and then just started using it on all spark plugs. Works good.

Champion Spark Plug Anti-Seize 2612 - 4 Oz | Aircraft Spruce

Champion Spark Plug Anti-Seize 2612 - 4 Oz Apply sparingly to second and third threads. Do not contact electrodes as it could short out the plug. Do not apply to shielding barrel threads.

www.aircraftspruce.com

 

[STRider]

Sounds like a job for Todd at Project Farm!

 

[oude geit]

Manu puts a clean dry engine, machine together. Maintenance, repair is done on a dirty, wet engines, machines. Working on aluminum engines can be a unforgiving experience.

 

[SMSW]

I was told to use this stuff on aircraft engine spark plugs, and then just started using it on all spark plugs. Works good.

I'm surprised at this. Aircraft engines are maintained much more rigorously than our ST's (or any automobile outside a racetrack). Thus, the plugs are not left in the engine for 75k or 100k miles (equivalent in hours) and thus I'd not expect them to be frozen in the cyl. head.

On the other hand, aircraft engines are mostly air cooled and see more severe service than bikes so what do I know?

 

[Ron]

I don't know about wet and dry clamping pressure comparison. I do know the 2nd and 3rd time a bolt or screw is used, the clamping pressure is higher.

 

[rwthomas1]

I'm surprised at this. Aircraft engines are maintained much more rigorously than our ST's (or any automobile outside a racetrack). Thus, the plugs are not left in the engine for 75k or 100k miles (equivalent in hours) and thus I'd not expect them to be frozen in the cyl. head.

On the other hand, aircraft engines are mostly air cooled and see more severe service than bikes so what do I know?

Yeah, me too. This stuff is watery, not like regular anti-seize. A small amount "flows" around the threads.

 

[Andrew Shadow]

I was told to use this stuff on aircraft engine spark plugs, and then just started using it on all spark plugs. Works good.

In response to the proliferation of aluminum cylinder heads, manufacturers plate the threads of spark plugs with coatings designed to prevent seizing. The corrosion between steel and and aluminum is an electro-chemical process. These coatings are designed to stop this chemical reaction. NGK used to, and may still, advise against applying anything to the threads of plated plugs, stating that mixing in additional chemicals not provisioned for can possibly make things worse.

Just passing on an FYI. I have applied anti-seize in the past before I knew about this plating and never had an issue. Since I learned of this, I no longer do so. I figure that NGK knows more about it than I do.

 

[RaYzerman]

In general with regular plugs, that's OK.... you're going to check them. I know those with Iridiums that neglect to check for double that and have had issues... if I use anti-seize I just put it on the bottom three threads...

 

[red one]

In general with regular plugs, that's OK.... you're going to check them. I know those with Iridiums that neglect to check for double that and have had issues... if I use anti-seize I just put it on the bottom three threads...

Replaced the factory iridium plugs at 120K on my Toyota. They were installed dry from the factory and squeaked a little but came out ok. When I hit 240K I'll replace these. With original NGK or ND's coated plugs should not be a problem.