Re-torquing Cylinder Head Bolts

Here's a spanner in the works:

I like CLEAN threads. You won't get DRY threads if you are doing it right - with Loctite.

Okay?

Furthermore - I torque them to about 70% of the "book value" all the way 'round the pattern, then I continue to 100% of the value on round 2.

Now, a show of hands: WHO HERE HAS ALL THE PROPER TOOLS TO TORQUE EACH AND EVERY FASTENER ON A NORTON HEAD?

One? Two people, MAYBE?!

Mick was right.

As for re-torquing, I do the oil leak check, timing, valve re-adjustment and carb setting, then nip 'em up a touch just to check. Then, I do an initial run-in of about 2 gallons of gas which is mostly riding, some fine tuning. THEN I do a check-round of re-torquing after the engine cools.

Argue all you want, it has worked for me without a head gasket failure EVER (over 35 years, over 100 bikes owned and 20 or so client bikes).

Wow--225 year ago--lets see--"1783'---I wasn't aware that Washington crossed the Delaware in a steam vessel.
Just kidding.

Click to expand...

LOL..... I am impressed that you did the math. I'm a high school teacher now and most of my students THINK that I was either in the original delaware crossing OR possibly on the same soccer team as Moses.

Have a great week, all.

I'm going to reassure the this old thread as I am standing in my garage with my iPad in the process of re torquing my Atlas head bolts for the first time since a rebuild 4-5 hundred miles ago. Process aside, what are the ft/lbs I need to be using?
Thanks!

Page 14 = 25 ft.lb.
http://www.classicbike.biz/Norton/Repai ... 0-1968.pdf

Thanks LAB- again!

As mechanics we were told to follow the procedures laid down by the manufacturer.
In the good old days most heads needed re-torqueing. Now days, very few do [ we a re living in an age where our customers don't want to pay for a job to be done twice, and there is so much crap o modern engines tat it would be a mission to re-torque heads hence the invention of the non re-torqueing gaskets and torque to yield bolts ].

The old procedure was to torque up in steps [ as per manufacturer ].
When re-torqueing after about 500 miles we were taught to back of the bolts then torque them up again., this was because a bolt or nut would effectively glue itself to the head and therefore may not tighten up to the necessary torque. By backing off, the friction is removed [ supposedly ] and the correct torque can be gained. I say supposedly because we are not magicians, soothsayers or scientists.

We were told to put sealers on bolts that went into water jackets, and generally lube the threads and heads of bolts/nuts. The lube stops galling of the threads and pressure surfaces like aluminium heads [ spark plugs ].

Dereck

Hi all.
There was a similar thread recently about dry/wet threads at loctite-not-whos-going-experiment-t22094.html
I am a dry thread camper but am about to try an ARP product on conrod nuts according to their (ARP) instructions.
They talk of torquing, releasing, torqing again, etc to mate the threads (my interpretation) prior to final torque. With their product claims single torque only now required.
Ta.

grandpaul wrote:

Now, a show of hands: WHO HERE HAS ALL THE PROPER TOOLS TO TORQUE EACH AND EVERY FASTENER ON A NORTON HEAD?

Click to expand...

I have the sockets and the torque wrench adapters needed for all the nuts on a 750 head. I made my own adapters about 2 inches long and have done the calculations to be able to use the proper torque on my inch pound torque wrench. I used and instruction booklet put out by "Sturtevant Richmont" http://www.srtorque.com They have the most comprehensive discussions of torque wrench use I have seen.

One little tidbit of information is that unless you apply the torque from the prescribed point on any torque wrench you will get a different amount of torque at the nut or bolt when the reading is the same or the clicker goes off. This one was a hard one to swallow but the math bears it out.

the purpose of measuring torque is to get the proper amount of stretch on a given bolt. Weather dry or lubricated it is the stretch you are after. Jim Comstock has measured it out for conrod bolts so, using his measurement for the change in the length of the bolt I would lube those and not go by torque but bolt length at start and finish. That method is harder when you can only access one end of a bolt though.
Dan.

The Commando has a pretty odd set of bolts and nuts to torque down and I agree precious few have all the tools to do it with a torque wrench. But I suggest that it isnt all that important what the torque figure is rather that all are pretty much even. But remember that too is affected by the fact the bolts and nuts arent all the same size.
Tighten them all up at least three go rounds and if you check close to a thousand miles as I just did you'll find a few looser than others.
My lawn mower is built to higher accuracy levels!

I garantee the vast majority of builders before us just went by feel. Some seasoned builders besides shade tree me found 5 more lb worked better than manual specs. My buddy Wes with Cdos all his life and cross country use taught me i was a whimp going by the manual and soon came around to his camp - do em up Tight once then check em w/o breaking free first for a labor and fancy tool saver. Do note the tq specs are for like new fasteners and each use of a nut reduces its thread form for less clamp force, so more twist harder each use for same bolt/stud stretch/clamp force, which would tend to up require tq by a few or more lb ft. Another man hood tester to me, can ya thrust your judgement/senses or need help. The way I see it is if a faster still leaks after manual tq and ya twist a bit more to try to seal it - then ya just gained a bit more man hood beyond following erratic rule book. To poke at the religious or impaired T-wrench believers, say in a current manufactured engine, a fastener not holding torque or sealing on listed torque would be reason to reject engine or recall all engines to fix the problem. So a really honest T-wrench believer would not try to break his rules with more tq but tear down and try to make engine fit manual specs.

I should have mentioned that I have CNWs Cylinder Stud and Nut kit as well as their Cylinder Head bolt and nut kit. Both are ARP stainless steel kits which have 12 point nuts and 12 point bolt heads. The sockets and torque wrench adapters are 7/16 and 3/8 12 point. This really did make it a lot easier to own the "full kit" and is not what grandpaul was talking about now that I think of it.

On the first couple of retorques of my cylinder nuts it seemed to have loosened more than I thought it would but then I realized that the paint on the barrels was giving way under the nuts and after that process finished the tightness held very well. I used an RGM copper base gasket and now that I have done that I can't really imagine going back to a paper gasket there.

Cheers

Motorson, Carillo also put out a chart for the stretch of the bolt and also a lubricant to suit their products
The lubricant comes in small black tube and is a brown runny paste.

To qoute from their chart

5/16" (thread) CARR (type) S5 (head marking) 0.0050 to 0.00070 (stretch recommendation)
40ft/lb (torque not to be exceeded)

I use these bolts in my race bike and after explaining to Carillo ( I wrote to their technical guy in the
States )the amount of use that I have given them , they have assured me that as long as they dont exceed their stretch or torque guidelines the bolts can be reused.
The stretch comes out at between 0.0057" and 0.0061" at 37ftlbs ( have just calibrated my 3/8" drive torque wrench to within 0.05 ftlb as indicated on the scale)

I feel confident in this advice and the bolts are the ones that come with JS Motorsport rods, each bolt is $42.00USD.
Regards Mike