Bolts, Oil, Torque ?

[droog]

Hi, I trust everyone is enjoying their weekend.

I'm fitting the CBR cam holder and have been referring to the Honda Shop manual and the Haynes manual for the CBR600.

The Honda shop manual and the Haynes manual seem to contradict each other regarding oiling the cam holder bolts:

The Honda Shop manual recommends oiling the cam holder bolts prior to refitting the camholder:

'Apply engine oil to the threads and seating surfaces of the camshaft holder bolts'.

The Haynes on the other hand doesn't mention oiling the bolts and even warns not to get any engine assembly lube or engine oil into the cam holder bolt holes as this will:

'affect the tightness of the bolts and the seating of the holder'

My personal understanding is that oil on bolt threads can throw off the intended torque wrench setting (12 Nm in this case) and can lead to either an over-tightened or under tightened bolt.

On that basis my instinct is to agree with the Haynes and leave the bolts dry - but on the other hand it was Honda who designed and built the bike and wrote the manual and presumably woulld have specifically prescribed 12 Nm in torque for an oiled bolt and not a dry bolt - so surely the shop manual is right in this and I should be oiling the bolts?

(the cam holder bolts came out as dry as a bone and showed no signs that they had ever been oiled in the first place).

Cheers for any advice.

[stinkwheel]

Well, I would generally go with the manufacturers workshop manual over an aftermarket one. They usually have a little indicator on the exploded diagram for which lubricants should be applied where too.

It does seem quite unequivocal in its written description though.

Probably less likely to snap if overtightened than a more traditional cam cap anyway.

Remember a torque wrench isn't a panacea, if it feels like you're overtightening, stop.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[droog]

[Nobby the Bastard]

By the same token, the official workshop manual for a particular bike states 'use threadlock' in a situation where it clearly shouldn't be used....
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trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[Bhud]

I am not an engineer. What I usually do is give them a quick blast with carb cleaner in case they picked up any debris from the bench or the floor, before putting them back in the head.
In that application, where you have very low torque fasteners, in my view overtightening could occur if the bolt is oiled or greased, therefore I don't do it. Also, it seems to be unnecessary, because you have mild steel bolts going into aluminium, the bolt's head getting sloshed over with lots of oil or just sitting there with a film of oil. This means it's highly unlikely that ionic transfer would take place between a cathodic steel bolt and an anodic aluminium threaded hole.

In your case, what I would guess has happened is that when Honda assembled the engine, they applied an anti-corrosion compound to those bolts. Subsequently, either the act of removing the bolts, or handling them after removing them, caused that compound to be removed as well. Honda, probably anticipating this, advises you to then oil the bolts with engine oil when reusing them. I don't know for sure that this is the cause. However, I would be surprised if those bolts could suffer galvanic corrosion.

[stinkwheel]

You could also look them up on an engineering chart to see if the torque value they are quoting fits with an oiled or dry fastener of that size, thread and grade.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[jeffyjeff]

[droog]

[droog]

[droog]

[droog]

[MCN]

[Polarbear]

OK, not specifically motor cycle applications but on 99.99% of machinery I have worked on they specify torque on a dry bolt or with a specific thead treatement ie, Loctite 242 or similar.

If it's a wet bolt, they normally say hand tight plus a specific further tuen of the bolt, ie, hand tight plus 180 degrees or plus 1/4 of a turn.

I would certainly not trust using a torgue wrench on a low torque oiled bolt, it's an instant receipe for disater in my view.
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Triumph Trophy Launch Edition

[droog]

[Polarbear]

You will be amazed how quickly that torque wrench clicks. Small torques are so misleading. It clicks while you think it is still slack. Just don't think, 'a nip up for luck'.
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Triumph Trophy Launch Edition

[droog]

[smokin joe]

A couple of times I've tried a torque wrench when fitting plugs to both cars and bikes, thought they felt way too tight before the wrench clicked and backed them off before using a plug spanner and going by feel. I've never had one come loose, but I'd rather that than hearing that horrible bang that denotes a stripped thread.

[droog]

[jeffyjeff]

[Easy-X]

Also, know your materials. Be extra weary of something like a 6mm bolt going into an aluminium block, e.g. exhaust manifold, versus steel on steel which can take much more torque.
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Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[droog]

[kramdra]

[droog]

[kramdra]

If you have them, just fit it. I did not bother to replace mine they were still good, no leaks.

[droog]