Forum

[stefaand]

Hello I've started the rebuild of the engine of my '55 bullet 350 this week, and even though I have all the manuals and such, i cannot seem to find the correct torque values for any of the bolts. Does anyone have these please? stefaan

[Mark M]

There aren't any, it was too early for this type of engineering precision! The only one that we have is for the cylinder head nuts which should be about 23 foot pounds (ft/lbs). Sorry, I don't know what that is in Metric but I can find out if you need it?! All other fasteners use your common sense and if you need reassurance use a drop of Loctite Thread Lock.

REgards, Mark

[papasmurf]

The main thing to watch is the finer the thread the more torque applied. This is important with 26 TPI threads as even 35ft lbs ends up as a ton load on the bolt.

Some tables:-
http://www.engineersedge.com/torque_table_sae_ftlbs.htm

https://www.swtc.edu/ag_power/diesel_en ... values.pdf

[stefaand]

Thanks Mark. My torque wrench has both metric and imperial measures, 23 ft/lbs is on it!
I'm a very inexperienced mechanic, this really is my first restoration as well as the first time I open an engine.
Thanks papa, these tables will surely come in handy.

I do have all the torque values for my triumph bonneville t100, would it be safe to use these values, slightly lowered?

As I understand, overtorqueing and undertorqueing can both be malignant for handling, for example the headsteady of norton's isolastic frame needs to be nipped up properly. Do you maybe have some torque values you have gathered from experience working on these machines?

stefaan

[Mark M]

I had a look for an online reference and couldn't find the tables on Papa's site. I did find values for modern bikes but as these are mostly Metric threads I think your idea of using your Triumph values is not a bad one. However, I really wouldn't worry too much about it; the cylinder head is probably the only one that needs accurate repetition (and also the correct "diagonal" tightening sequence) so on balance I'd say it's time you learnt the right "feel" technique! The fine (BSF) threads into alloy need special care but if you use Loctite you should be ok, just be gentle with these in particular!

REgards, Mark

[PeteF]

I've seen torque values quoted for the major fastenings (Pete Snidel's book has two pages of them)

[PeteF]

Doh! Read the original post! The values in Pete's book are for Indian Bullets of course. Possibly not a bad guide though.

[vince]

The torque settings are in hosts catalogue!

[Presto]

These figures from the manual may help ---------- all in Nm. ------------Note: if threads are lubricated reduce torque figure by 25% ------------Cylinder head nut 32; Cylinder head mounting studs 12; Cylinder base nut 10; Rocker bearing stud nut [not Samrat] 12; Rocker bearing stud nut [Samrat only] 6.5; Rocker cover nut 14; Rocker oil pipe banjo union [5/16] 10; Rocker oil pipe banjo union [1/2] 15; Timing shaft nut 90; Crank pin nut 135; Crankshaft worm nut [LH thread] 92; Oil feed and return filter drain plug 30; Oil feed plug [oil ‘quill’ nut] 15; Oil filter cap nut 13; Engine sprocket nut 55; Alternator nut rotor 55; Spark plug [< - i.e. less than] 20; Exhaust pipe fixing nuts 25; Clutch mounting nut 55; Clutch mounting nut [5 speed] 73; Crankcase joint nut m6 [1/4] 9; Crankcase joint nut m8 [5/16] 10; Timing cover screws 10; Primary chain case centre attaching nut 13; Gearbox end cover bolt [1/4] 10; Gearbox end cover bolt [5 speed] 7.5; Gearbox sprocket nut 63; Gearbox sprocket nut [5 speed] 73; Main shaft nut gearbox [LH thread] 63; Gearbox fixing stud nuts 32; Chain stay stud nuts 35; Wheel axle nuts front and rear 65; Brake cam nuts 20; Shock absorber nuts 25

[Presto]

NOTE - those figures are for Indian models - but many will be the same as UK made.