[LJRead]

Hi all,

This past few days has been interesting as I came squarely up to the problem of torquing my head bolts.  I wasn't entirely satisfied with my torque wrench (TW), and, it turns out, with good reason as I am at the lower limit of accuracy and found it is just to large a TW to give good results.  It's range is from 30 to 150 foot pounds and it is just too big.  So I got out Pete Snidal's manual and started looking at things more closely.  It seems that the head nuts should be torqued to 24 foot/ pounds, or below what my TW will do. 

Then I started to look at other torque values that Pete has given, and even went further and surfed the net a bit to find out more about the subject.  It seems that many mechanics have half a dozen or even more TWs in various ranges and types.  Interesting, though more inconvenient, the old beam type are the most reliable and others should be calibrated by a professional calibrating service at intervals.  If one drops his modern TW it is likely to be useless and other rough usage has a similar effect.  The cost of recalibration is high and the TW must be sent off to get it done.

So there is discussion going on, with people like myself (infrequent users), saying that if one is careful and doesn't abuse and turns the torque adjuster down to just above zero, there shouldn't be a problem.  Anyway, if it is close, the main thing is that it will give even torquing of, like, head bolts or nuts. 

Then I got further into Pete's manual and found values for all sorts of bolts and wondered if anyone really used a torque wrench for these.  I did go down and test a few of the cover bolts (gear and timing) with a screw driver and found them to be 'falling out' loose.  Remembered too an Indian mechanic guru on Enfields who recommends just getting a feel for the bolt tightening and just tighten to a point where there is some feeling of pull to the threads.  This seems quite correct.  And I remembered clamp's description of his mechanics teacher disparaging use of a torque wrench, saying a good mechanic should be able to do it by feel, and if not, get out of the game.

On the various threads there seem to be some who use their TWs every day, multiple times, and there was one bike mechanic who claimed the need for a certain type of TW for a certain bolt on the bikes he works on.

Well, I grew up at a time when we just begged or borrowed (or rented) a TW to do the head bolts and that was it.  I can remember that I broke a few until I learned the art of not tightening too much, and I get the feeling that if I don't use a TW, I have a better feel for the bolts and an idea that they in turn feel a bit more comfortable in being snugged down but not too snug.  I get the feeling too that a mechanical contrivance like a TW depersonalizes the process.

 I suppose the question here is, do you torque much or very little?  And if you tend to torque, which bolts in particular do you do so to.  Just trying to get a feeling of what Enfield mechanics are about.  What sort of TW do you prefer?  How often does it get used?  And, do you send it often for recalibration, something pretty impossible for me to consider.

Well I managed to find a good deal on a TW of the so-called clicker type, then went ahead and bought two of the beam type, one for low torque values, one higher, and that one I can used to test the clicker against - sort of a home brew method of calibration..  And I have my old 30 to 150 ft/pound clicker in case i need to get serious about some of the bigger ones.  Probably I will rarely use any of them!  But I suppose that if I m going to pretend to be a bike mechanic, I should have the proper tools to complete the image.

[The Garbone]

Well,
If a value is given in Petes book I bust out my trusty $14 Harbor Freight TW and go to town...  Admittedly I am a bit ham handed and I like the control and safety margin the  TW gives over the old feel method.  As for pattern I try to do the opposite and then opposite left type thing...

My TW is a clicker and I chose it because the values at mid range fit quite well with what the RE requires.

At my job we have fiberglass apparatus cases that use aircraft bolts,  If you torque them past the required 20lbs the heads shear off.. I have broke a few in my time...

[geoffbaker]

I bought my old beam TW used from a used tool store. Cant say it's very accurate, but it is nice to know you are setting something (say, head bolts) to a standard torque, and it is equal across all bolts.

Mine is the old scale type, goes from 0-100.

I've never had a reason to doubt it yet; I'm sure it is a couple of pounds off but short of something high-tech and expensive, it's the best I can do...

[PhilJ]

The more I learn about TWs the more I think you are right on track Geoff. After all an absolute number isn't so important as the uniformity to which you refer.

[LJRead]

There was a question asked on one of the threads:"why don't more mechanics use beam torque wrenches".  The reasons given had mostly to do with convenience, since in some situations it is difficult to read the beam wrenche's scale.  On R E this shouldn't be a problem since we are working on a simple, open type bike with few hidden corners.  The beam wrenches such as yours, Goeff, are more accurate (usually within 2 percent as compared with four to six with the others),  and they don't normally go out of whack as to accuracy - they aren't subject to recalibration.  One car mechanic mentioned he normally uses the clicker type for convenience, but when it comes to critical jobs like head bolts, he goes back to the older beam- dial type.

Another case where progress hasn't been such a great thing.

[LJRead]

A little more study done on the topic of torquing and it seems that a lot of care is needed throughout the process.  First is the treatment of the TW itself, an instrument, really, rather than a tool - it needs to be kept in a good environment and not simply thrown in the toolbox.  Then the bolts and nuts themselves have to be clean and the best policy is to us a thread chaser to make sure they are cleaned right (but not a tap which would take material off).  The underside of  bolt head, of course, must also be looked to so that it doesn't bind up when torquing down. 

The thing that interests me is that GM in its car specs call for torquing to be done after application of thirty weight oil.  They apparently spend a lot of time researching build methods and came up with this, giving their torque measurements based on having this oil coating.  Is this common practice?  I wonder how many R E mechanics take this kind of care or do we just put them back together after disassemble?  And are the torque values given, based on putting the bolts nuts or studs in dry? 

Am I beginning to feel a bit compulsive about all this?  Well, I'm used to working with fine equipment back in my times in the lab, so it wouldn't bother me to take pains, but I would need base line data to begin with and some feeling of how they were produced (oil vs. no oil for example).

In many situations working with engine parts, oil will be involved, sort of naturally getting to the threads, so it makes sense just to ritualize the process and add it ourselves.  But what did the manufacturers do when they came up with torquing tables?

Geez, at this rate maybe I should apply for a Ph.D. in torquing.  But then I suppose I would have to get a job (horrors!!!)

Some of you real mechanics like ACE and Vince, what do you tend to do?

[scoTTy]

I don't profess to be a real mechanic..  I tried that at one time..  figured the best thing I could do was to be rEaL quite about whaT I do Know....  from over 56 years of  taking things apart and putting them back together again.. I started early.. I'm 61..  tore my first toy tractor apart a long time ago

AnYwY.. last time I torgued the heads on the RE I used an iNch pound clicker..  I have a beam.. but its over 40 years old..  I just use it for back up now..  besides my head is to big to squeeze it between the frame and motor to look at the beam scale.. and I would have to use at least 3'25 reading glasses to see the scale

[Motor]

Real men don't use torque wrenches (TW) or timing lights for that matter...   perhaps a fire extinguisher.

Motor

[geoffbaker]

and I would have to use at least 3'25 reading glasses to see the scale

It's not the accuracy of the tools that are important any more... its the strength of the eyeglasses we need to read 'em now!

[scoTTy]

 

[clamp]

Dont pull ---push--with you index finger (thats the one next to you thumb in your mouth)

    Its unlikey you will be able to push with the pointed end of this finger to a torque of 35Ilbs on a 1 foot wrench --spanner thingy.

     It like pulling your underpants up,-- knowing when to stop or you get slack nuts.

[LJRead]

I looked at a TW on ebay the other night, called a "Vintage Cornwell Skidwell", apparently a top of the line tool made by the oldest such tool company in the U.S.  Some years ago they must have split as now there are Cornwell tools that compete heads up with Snap-On.  I past the TW by because the ad said that it was missing the adjusting knob, but when I looked at the tool a second time, it looked too pristine to have a missing knob, so I began to wonder, quickly made up my mind, and bought it.  I figured if the knob was missing i could manage to make one.  Finally i found through a search the same sort of TW made by the Skidmore Engineering Co.

Now, throughout my long TW study, I came to know that there are TWs used by companies for production where the torque is set in the wrench internally and is meant to stay that way throughout the production run.  They don't want wrenches that are easy to change the torque on. Some even require a special tool and have no scale, they have to be set using an expensive electronic calibration system.   They don't want the production workers to be able to easily change the torque setting.

To make a long story a little shorter, I wrote to the Skidmore Engineering Company attaching photos and asking if they had made it,  and today received a  reply from its president, Ray Skidmore which follows:

Hello Mr. Read,

From the pictures, the torque wrench you bought was model TQ-00-RA, which stood for a 1/4" Ratchet adjustable SKIDMORE torque wrench which we private-labeled for Cornwell Tools Co. in the '50s, '60's and '70's.
The adjustment was accomplished with an Allen Wrench which fits the socket set screw in the handle end. There was no knob.
Be careful not to adjust the scale below 0, as there is a small ball above the adjusting screw that will get out of position if the screw is loosened too much.

We still make these, but not for Cornwell. I estimate that yours is at least 30 years old, and possible as old as 50 years.

I hope this is helpful.

Ray Skidmore, President
Skidmore Engineering Co.


   In other words, it was internally adjusted and there never had been a knob.  Skidmore apparently supplies all the major U.S. auto makers with TWs, so they must be seeing a slow business period at present.  Maybe that is why the president of this large company had the time to send me an email!

  Here are some photos of it.   Figured a vintage TW of this age will go well with my vintage RE.

[pknopp]

 Some of the best buys can come off eBay when the seller doesn't know what they have and mis describes it.

[UncleErnie]

I look forward to pictures of your luanch of scientific instruments into outer space. 

Just curious;  is take-off going to be from your back yard, or have you picked a parking lot somewhere?

[LJRead]

Yeah pknopp, I bought my British made goggles for about ten bucks (over a hundred online) because the seller had misspelled "goggles"  and it wasn't listed in the goggles section on search.  Since my own spelling is often questionable, I probably misspelled the word myself when doing the search!  There are so many 'good deals' that one can easily spend himself into the poor house!  If I lived in the U.S. I could sometimes do a better advertising job and resell the stuff at a profit.

Well Uncle Earnie, truth be told, I launch myself into outer space every morning when my alarm goes off at six o'clock.  I guess that is why people sometimes refer to me as a 'space case'.  I do like the peace and atmosphere up here but it gets a bit lonely at times!

[geoffbaker]

my brother spent a couple of years making good money buying netsuke (the Japanese ornamental ivory pieces) off ebay by searching under misspellings of netsuke... he always got them cheap that way then resold them...

[LJRead]

Those instruments you mention, Uncle Earnie, now consist of a total of four torque wrenches, 30 to 150 ft. lbs, 150 to 1000 inch lbs, 0 to 100 inch pounds (my only beam type since I didn't buy a second after all), and now 0 to 120 inch pounds,the Skidwell one mentioned above.  The beam one will serve to check on the Skidwell, since it should be very accurate.  It bothers me a little that I don't yet have the 120 to about 170 range covered (the accuracy of the 150 to 1000 TW being limited below 170 inch pounds according to manufacturers specs).  I am in the process of making two simple crows foot extensions which will solve that problem by extending the range of both the small TWs.  One of the crows feet will be for spokes to replace my jury rigged one.  I know the conventional way to torque spokes is to bang on them for tone, but in my experience this is highly inaccurate - better to start with torque then adjust the wheel for trueness.  It seems to me that spoke torque or tightness is crucial if w are going to ride on spoked wheels.

Some points that may be of interest here.  If an anti-seize compound is used on the bolts then you reduce the torque by 20% to allow for the easier torquing of the bolts.  The one torque table I have gives torque values for dry bolts so if 30 weight oil is used I guess a 20% reduction would be appropriate - I may run some tests later to see.  Sometimes bolt stretch is used instead of torque in crucial situations, but I don't know how I would measure stretch in most situations. In RE we are dealing with bolts into aluminum so I guess bolt tightness would be more critical if we don't wish to strip them out.  Now there is a move on to use torque angle, which I suppose gives a measure of bolt stretch.  One reaches a set torque angle for a bolt, then goes either 90 degrees or 180 degrees beyond it, said to be more accurate than torque.

In the military, every single bolt nut and screw in the fighter jets is torqued, but I guess at mach two one would want to be careful.  Some professional mechanics posting in the threads torque a lot, others limit it to internal engine and transmission parts and head bolts and sometimes manifold bolts and leave it at that.

I know I'm being compulsive over torque, probably due to my inexperience.  It is like an experienced cook giving a pinch of this and a palm full of that ingredient, versus a newbie having to measure everything out. 

[geoffbaker]

Well, it's better to be overly compulsive than not, especially in the case of engines with aluminum! Any overtorquing can cause damage.

I've learned this through experience!

But I would also say that my ancient, probably inaccurate beam TW has never caused any problems, so I guess it is close enough!

[LJRead]

The only problem I could see with using your ancient beam TW, Goeff, is that its range might not be great enough to cover the range in torques required.  It is probably more accurate than a modern clicker type, at least if you are able to read the scale.  It seems that most or all TWs have an accuracy range limited to 20% to 100 % of their maximum torque.  Thus if a TW has a scale between zero and a hundrred ft. lbs, anything below 20ft. lbs is suspect.  The really nice TW I bought has a torque of between 150 to 1000 inch lbs (12.5 to 83 ft. lbs.) but I can count on its values for only between 166 and 1000 in lbs, the higher values in the range are said to generally be accurate, it is just the lower ones that aren't.

Yesterday I replaced the brake disc on my car (4 wheel drive SUV) and because I've gotten into torque, I used my large TW (20 to 150 ft. lbs) for all the bolts in the hub and brake and found it to work very well. I have had that one for years but only used it a few times, but now will use it more often.  There is a ring of six bolts around the outer hub cover and a ring of six holding the disc onto the hub, and it seems good that they are all at the same torque tension now.

As you say, with aluminum all this will become even more critical.