How many washers on engine mount bolts?

[Martin K]

I was always taught that a flat washer goes against the flat surface, flowed by a sprung or anti-shake washer, and then the nut.

If I follow that convention on my FH engine tie studs, that’s 4 washers in total, and there isn’t enough length on the tie stud for the nut to fully engage (photo).

So I guess I’m wrong - in which case could anyone help?

Do I go with an anti-shake washer (will damage the paint) or a flat washer (protect the paint but worry that it shake loose.

I know - I really need to get out more……

[Mick D]

Hi Martin

I would challenge your convention - in my opinion it's either or.

In this case I use a plain washer under each nut or head and no spring washers. In the case of a joint subject to loss of torque due to vibration, a spring washer only.

The plain washers supplied by Acme Stainless are slightly thinner than standard period ones so can usually be used to protect the finish where no washer was fitted originally.

Regards Mick

[simon.holyfield]

Hi Martin

I would challenge your convention - in my opinion it's either or.

In this case I use a plain washer under each nut or head and no spring washers. In the case of a joint subject to loss of torque due to vibration, a spring washer only.

I agree, and would add that a fastener with a fine thread, like CEI, doesn't need a spring washer.

[Martin K]

Thanks chaps

New convention now dutifully installed!

And a great point about fine thread like CEI gripping tight.

Single washer from now on.and I’ll contact Acme too.

[Mick D]

I agree, and would add that a fastener with a fine thread, like CEI, doesn't need a spring washer.

Hmm!

It's my feeling that if a spring washer was originally fitted by design it's probably there for a reason and I fit one

Regards Mick

[Martin K]

Without dragging this into surreal lengths about (let’s face it) a not very important issue - I am left puzzling over why I have SO many washers (of all kinds) left over as I rebuild. No nut/bolt/screw has been left unprotected, and yet I have a handful of unwanted washers still looking for a home.

Perhaps they self-reproduce in the dark?

Perhaps I’ll wait till something drops off (the bike, I mean…) in use and then realise ‘it should’ve had a spring washer on that one’ etc

[simon.holyfield]

I agree, and would add that a fastener with a fine thread, like CEI, doesn't need a spring washer.

Hmm!

It's my feeling that if a spring washer was originally fitted by design it's probably there for a reason and I fit one

Regards Mick

Quite agree, I do the same myself - as you say, where there might be a vibration problem or where a coarse thread is specified for some other reason (like threads into alloy for example).

The trouble with Ariel parts lists though is that they don't specify standard washers by location - or not consistently. Happy to be proved wrong on that point.

[JohnnyBeckett]

hi i just use flat washers like when the ariel left the works and i do not have problems with the nuts undoing