torque on jug bolts

[Skip]

Can some one tell me the proper torque on jugs bolts to the cases...and if there is a problem with one backing off? how about head bolts also...Thanks. DB

[Skip]

Thanks...DB

[Jack_Hester]

I have always had a problem with 65 ft/lbs of torque on the head bolts. That is an awful lot. I will use a term that Cotten spoke of. When I tighten head bolts, I snug until there is no more 'creep'. I warm the engine up. Then, feel for more 'creep'. This will happen several times, until I am not taking up any more slack. I'm not talking of pulling hard. It's just something that is learned. Sometimes, by pulling too much, and learning the hard way. And, if you are following behind a number of unknown rebuilds, watch out. Head bolts and cylinder base studs will show up with problems, if you are going by a torque spec. Especially, on Flatheads. If you want a funny feeling, torque a headbolt that been over torqued, and feel the threads coming out of the cylinder. Or, feel a cylinder base stud coming out of the case, and you know you haven't pulled it hard. 35 ft/lbs is quite a bit for a stud threaded in aluminum, and it's already be stressed by someone who never heard of pulling to find the 'creep'. Torque specs were created for big arms, or people who never learned that everything doesn't have to be as tight as they can get it. Anyway, thought I'd speak my mind.

Jack

[Skip]

my dad always told me to tighten until it made noise...thought I'd better check this one first...have damn acorns for jug bolts...just noticed the front left backing off about every 150 miles...less than finger tight last time...will use a crows foot and see what happens...Thanks...DB

[Cotten]

Our major concern is not one of getting fasteners so tight that they do not loosen. They all do with the cycles of heat. The concern is that fastener torque distorts the cylinder bores when fitted to moderate piston oversizes.

Therefore, not only is important to avoid over-torquing, but it is of great importance that opposing fasteners be torqued evenly. And maintenance re-torques must return to the same degree of distortion.
This is difficult in the chassis, as the approach to getting a wrench upon each fastener is different.
Hand-grunting them with your tonque held between your teeth will not give an even nor accurate torque from fastener to fastener, wrench to wrench, hopping back and forth from one side of the machine to the other.

So a readable torquewrench and extentions for each approach is prudent.

I torque big twin base nuts an extra 5 to 40 ft/lbs, but that is after the cylinder has been fitted while torqued into plates at that spec.
Flatty heads spec at only 55, and I imagine that Jack is correct that 65 may not really be warranted for OHV's, .... but that's the accepted convention.
It is quite possible that such a high torque only pulls the inserts on a stock Pan motor.

....Cotten

[Skip]

it is my understanding, and PLEASE correct me if I am wrong, but extensions and swevels and the like take away from the torque setting on your wrench...and how do you get a torque wrench on the front bolts of the jugs??? Crows foot? I did well to get a open end wrench on them...Thanks for the knowledge, I try to soak up all I can...sometimes you need ear plugs to keep it all in...DB

[fourthgear]

I am another that only uses a torque wrench on things like axle nuts and other bearings. I use lock tight on everything but head bolts ( I use motor oil on the threads ) As Jack said its all in the experanced feel on head bolts , & base nuts. You get the feel with a lot of head bolt tightening, after all you are eather pulling on a steel insert or a stud in alum. and add to the mix the age of the casting we are working with . Not that torque wrenches don't work , its just ft.lbs.specs from fasener to fasener on old cast alum. ,may be a bit too much. my two.

[Cotten]

DB!

If your adapter extends the length of the wrench, the torque reading is multiplied; if it shortens it, it divides the reading. So, if your adapter makes a right angle (90*) from your hand... to the head of the wrench... to the fastener, the torque reading stays the same!

A cheap torsion wrench that has the double squaredrive plus an obstruction wrench ("C"-shaped with a 5/8" and 9/16" boxends) allows four different arrangements to torque headbolts.
Add a 9/16" allen drive to flip the obstruction wrench to the 5/8" end, and you have four positions for the base nuts.

Anyone who holds a dialbore gauge to a torqued cylinder bore and witnesses the distortions will never grunt-torque a cylinder by "feel" again.

....Cotten
PS:
Torquewrench joke: Clickers!

[fourthgear]

First, whats a dialbore gage? would that be an dial indicator for bore sizing?Maybe my barn yard mechanics tool box is a little light and maybe I don't want or need to know some things about whats going on when torquing some thing , I only know what works and what doesn't. When you start adding ,subtracting for diff. angles or extentions and working mathmatics (which are making it all theory then) you have no idea what you are truely comming up with, sure it may make you FEEL that it is as close to specs as you can get but, do you truely know. Those clickers are used by every mechanic I know and have known , not that there isn't other types , I kinda wounder what they use for the engines that are in NASCAR race cars.

[Cotten]

Fourthgear!

Just because you haven't the tools at hand, it doesn't mean that you should toss horsepower to the wind or suffer premature wear. Unless you can see a thousandth of an inch (one-third of the thickness of a piece of paper), measuring instruments are the only way to determine if a bore is truly round and straight.
And an instrument will show you that a properly torqued .050" overbore can distort from installation a thou inward between the base studs, and a thou outward just above the studs for a full two thou out of round. UH,...where'd the clearance go?
At larger overbores, you will pinch the piston upon assembly! (That's how the "thin cylinders run hot" myth originated.)

If you grunt them subjectively, the distortion will be much greater.

This is avoidable with very primitive (and cheap) tooling.

Clickers are for mindless production tasks.
They are awkward, expensive, and need scheduled re-calibration. Reproduceability suffers with poor technique. And they are blind.

The cheapest imported dime-store torsion wrenches have a pointers and scales, and are surprisingly accurate.. You see what torque you are applying. You calibrate it by massaging the pointer to zero. The slim double-drives make them use-able because you can reach those hard places.
No bells, no whistles, no flashing lights. No springs to fatique, no cogs to round off. A resourceful technician could easily fashion his own.

Sorry if making a right angle out of two wrenches was higher math.


....Cotten

[Skip]

what brand/type do you use and recommend...needing to buy a new one soon...Thanks...DB

[Red55FL]

Fourthgear
Yes, a dial bore gauge is a dial indicator with a sled and a long handle that is used to slide up and down a cylinder bore to quickly measure it.
And Cotten is right, you can measure the measure the deformation of a cylinder caused when torqueing head bolts and base bolts. This can easily be seen by lightly tightening an inside micrometer across the inside of a cylinder so that it will stay across the bore, then, using just your hands, push on the sides of the cylinder at a 90 degree angle to the micrometer. You will be amazed at how little you have to push before the micrometer falls out of the bore. I have never done this with HD jugs, but I have done so on air-cooled jugs that are larger and thicker than HD’s.
That is why Cotten advocates the use of torque plates when boring and honing so strongly, and rightfully so.

Cotten
Mechanics are a hardheaded lot, I am as hardheaded as any and from reading your posts, you are too. I have a lot of respect for you and have learned much from reading your posts here and on other sights. However; I too do not agree with nor understand your strong assertion that clicker type torque wrenches are bad. If improperly used, beam type torque wrenches are worse than not using a torque wrench at all. Most people don’t use a beam type properly. They don’t keep the handle centered on its pivot pin; they don’t pull directly in the same arc as the fastener is turning so that the pointer doesn’t rub in the guide and they don’t take care to make sure the pointer doesn’t get bent. All of which makes the use of a beam type very inaccurate. Add to this the fact that a beam type can’t be recalibrated and thus can’t be recertified; it is not the torque wrench of choice for most torqueing jobs. True, a beam type is cheap and if it is bad, you can just throw it away with out much pain.
I own 3 good beam type torque wrenches that I bought back when I was 15 or 16 (a long time ago) and still use them from time to time, but the lions share of torqueing is done with my clickers. True, they can be improperly used also, but they are a lot easier and faster to properly use than beam type. If properly used, you can “feel” the fastener pulling down right up to the point where the proper torque is achieved and the wrench clicks so that you do not over torque.
Not trying to stir anything up, just voicing my opinion.


*Notice I use the word “mechanic” and not the new word “technician”, when they started using the word “technician”, the maintenance and repair world went to shit.

Red

[Cotten]

DB asked:
>what brand/type do you use and recommend

The cheapest of course!

I have an antique Hastings and an antique Plomb that both produce the same readings as any Buffalo or Hoo-Flung-Poo.

Only the orientals have the double-drives, I think. Try Harbor Freight http://www.harborfreight.com/

(Actually, I lost count of my torquewrenches, but I do remember that the closest thing I have to a clicker is a Sunnen with the 'breaking elbow'.
My most recent find in a dumpster was an elegant parkerized Caterpillar Snap-0n-style dial torsion wrench. But I have never found a 'clicker' that has survived!)


....Cotten
Late edit:
Red55FL!
I used the term technician to distinguish from engineers.
And I only type hard-headed!

[fourthgear]

With any torque wrench or just the wrench , if you are using ANY kind of attachment you WILL alter the readings of the torque wrench by the extention or adaptor of any kind . You get into the math of lenth vs angle and all the stuff that you really don't need or want to know.
You say the jug is moving when you torqueing it down , what happens when it heats up and you re-torque it down , the motors already together and no way to put the tool inside ( I assume it goes into the bore ), what happens then , you have no way of knowing what the heating up of the motor has changed or hasn't and then you are going to re-torque them with out your tool.
I agree with you using the proper tools for the job but , only where the out come can be benifited by using them. The head bolts and base nuts are the most ackword faseners to get at properly with any tooling.
As far as the bar and pointer torque wrenches , I do use one a real old one , but I don't use it on wrenching of any kind , I use it on tightening barrel nuts on M16 rifles because you have to alien the gas tube notch with the hole in the receiver for the gas tube and its torqued @ 50ft. lbs. and you have to go over or under to alien it , in other words you have to see it. I really don't trust it for any thing else.
As far as motor life , I have restored HDs out there with twenty plus years on them and no problems and I also have a great respect for your knowlage and experance but there are other ways of doing thing properly.
The man I learned a lot from was A guy named BUd at Elyria , Ohio HD dealer and he told me just to throw that torque wrench back in the tool box when tightening head bolts and base nuts , this was back in the early seventies and I was rebuilding my 56. This old dude was the only one in the area that you could talk to and pick his brain about Panheads and he was the best.

[Guest]

Once again for clarity:
An extention that forms a right angle does NOT appreciably change the torque value.
Even when minor flex is introduced from a long extention, it is still much less significant than the human error of guessing at even-ness. Even-ness is MUCH more critical than a pound or two of accuracy.

Bore distortion from fastener stress is observed while installed in torqueplates. This reproduces the static conditions of an assembled motor.

With all due respect to beloved old-timers, just because they were bare-assed-barnyard doesn't mean must be.
With today's enormously inflated prices, crystallizing metal, overbored cylinders, etc., we can no longer afford to fix everything with a hammer.

Today's enthusiasts have much higher expectations, for very real reasons.

....Cotten