TOPIC:

I always fit an additional 2mm washer onto of existing washers on the head bolts to take up any stretch from before.

Also ALWAYS grease the washers & base of each nut so they turn easily as you tighten them, rather than grip the head & begin to stick.

Pete F

It is very important to lubricate the threads and seats of the nuts and washers.
When I was doing my apprenticeship (more years than I care to think about) as a fitter we were shown just how important it is. First a cylinder head bolt was torqued up to the specified tension , 65ft/lb I think it was, with dry threads but clean and the seat tension was very close to 1 ton. It was repeated again using an antisieze compound like Permatex never seize and the seat pressure was just a touch over 4 tons and then again with the same lubricant on the washer and nut seat and the seat pressure went to almost 5 tons.
That is as you know just how important it is and every thread should be lubricated unless the manufacturer says otherwise.
I have seen racers blow gasket after gasket and wonder why until someone takes pity and tells them.
And about bottoming the thread in the crowned nuts on the bike in my avatar I always machined the top of any nuts I ever used after I figured out what happened

RickG

As ever, first class advice clearly gained from years of experience.

I was taught very much the same as you by my old Foreman Mechanic (god rest) when in my Motorcycle Mechanic apprenticeship back in the late 70's.

I still go back to all that advice in my mind from over 30 years ago every time I work on an engine.

Respect

Pete F
UK

Hi All,

Just reading RickG's comments regarding bolt loading and the importance of clean bolts/nuts and a high quality lubricant, I have attached a couple of slides that will open ones eyes! Well done RickG in mentioning this fact. I am in the fluid sealing business and deal with torque loadings, gasket stress etc. on a regular basis. Hope you all find this interesting. Good luck Propforward on your rebuild!

Regards

Craig

Thanks Fellas, more solid advice!

I will make sure to do this when doing the rebuild.

I am really glad I signed up here.

strate6 wrote: RickG

As ever, first class advice clearly gained from years of experience.

I was taught very much the same as you by my old Foreman Mechanic (god rest) when in my Motorcycle Mechanic apprenticeship back in the late 70's.

I still go back to all that advice in my mind from over 30 years ago every time I work on an engine.

Respect

Pete F
UK

Much the same here when I do a lot of things I think of what the fitter I was paired with in my first year. he was a New Zealand Maori and a man mountain, about 6'8" and 300lb and one of the 1st things he said to me was in a very deep and gruff voice :I don't care how many dumb questions you ask but you make even 1 dumb mistake and I'll kick your arse till your nose bleeds because dumb mistakes cost lots of money".
I have repeated that very same thing to quite a few apprentices I have had as offsiders over the years.