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TR4 CYLINDERHEAD TORQUE SETTINGS

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The workshop manual states 100 to 105 lbft, or 13.826 - 14.520 Kgm

 

Viewing the engine from the manifold side, the sequence is:

 

9 . 3 . 1 . 6 . 8

7 . 5 . 2 . 4 . 10

 

mike

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I always tighten the head down in stages.

Start off at 25lbf then go up in 50lbf and 75lbf before tightening to the full torque.

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I always tighten the head down in stages.

Start off at 25lbf then go up in 50lbf and 75lbf before tightening to the full torque.[/quote

 

+1 that's the correct way to tighten any joint held by more than 1 nut or bolt

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I always tighten the head down in stages.

Start off at 25lbf then go up in 50lbf and 75lbf before tightening to the full torque.[/quote

 

+1 that's the correct way to tighten any joint held by more than 1 nut or bolt

 

+1 and remember to use a torque wrench that is calibrated or at the least newly bought during the last 12 months. Also remember if you wind too much torque on and need to reset DON'T just wind it back down to the figure it should have been set at. Wind it well below the limit you wish to set by at least 20 lb ft and then reset the wrench in a smooth movement backup to the torque you wish to apply. Oohh ...and set it with a hot engine. Incorrect only for retorquing after couple of hundred miles. MR.

 

Mick Richards

 

Edited by Motorsport Mickey

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I note you say set it with a hot engine but clearly you can't do this first time around. Also, I thought the manual says do it cold?

 

Rgds Ian

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I note you say set it with a hot engine but clearly you can't do this first time around. Also, I thought the manual says do it cold?

 

Rgds Ian

Whoops...I read the first post as being "retighten" (not tighten) as in being retorqued, thanks for the correction Ian. Obviously first tighten is on a cold engine it never having been run, although when I retorque I do it on a hot engine.

 

Mick Richards

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I had my torque wrench for my 21st birthday, maybe I should buy a new one !!

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Just calibrate it - it may be fine.

Known weights on the end of a lever of known length

simples

 

Bob.

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How do you know the bendy bar one is reading correctly Ian, has it been calibrated?

 

Tim

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Tim,

 

If they are both reading the same when the "click" is heard, I suppose the chances of them both being incorrect to the same extent a slim?

 

I read somewhere that the bendy bar (deflecting beam) type were more accurate/less prone to going out of tolerance. (?)

 

Mike

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I'm sorry I started this now Mike. I have two torque wrenches - a bendy bar Elora, which was my father's and is nearly 50 years old and a click type by Da Jiun of Taiwan purchased from a Lidl store is Spain some ten years ago, it has a TUV sticker but I suppose anyone could apply one of those! It appealed since it has a higher maximum capability than the Elora. I tried the two together as Ian suggested with the following results, all values in lbs ft with Elora readings first and corresponding Da Jiun readings in brackets:-- 25 (25); 36 (40); 54 (60); 60 (70); 75 (85) and 80 (95). I reckon my money is on the Elora, as I say it is nearly 50 years old but the zero hasn't moved in all that time. I will have to find a way of following Bob's idea of using a known weight at a known distance - reminds me of moments in school - so I can decide between the two.

 

Tim

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Interesting thread. I bought a torque wrench 2+ years ago at Stoneleigh and have not used it yet. It's still in its original packaging.

 

Am I going to need to have it calibrated before I can use it?

 

Thanks.

Sean

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Hi Sean,

you will not need to re-calibrate it as it probably wasn't calibrated in the beginning.

If it is a bendy bar type then they are made to be about right but not calibrated

The spring type should be calibrated but are quite expensive.

 

As Bob mentioned it should be straightforward using a heavy weight and some string.

 

Roger

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And don't forget to back off to lowest torque before storing it away.

 

Bob

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It's a spring which set's the release torque, & like all springs if you store it under compression (or tension) then it is likely to relax to it's new shape, which means it won't be accurate any more. Unwinding the setting to minimum puts the least amount of compression (or tension) on it.

 

Bob.

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Well if you go onto e bay you'll find some Acratorque calibration meters for sale. I bought mine for £30 about 30 years ago from Anchor Supplies who specialise in ex Military equipment.

I have a bendy Torque wrench which I've checked against it and they both compare bang on. The Acratorque guage I believe is very similar using tension upon a preordained tensile strength beam to develop the torque, then converting it to a calibrated "clock face" they are pretty bomb proof unless you drive over it or set it on fire !

When I buy a new torque wrench (about every couple of years) I cross check it's calibration (they are supplied with a certificate) against the Acratorque so gaining a "duo" check each way against one another.

 

The Acratorue comes in a variety of sizes mine is a L3 which covers 0-400 lbs ft in 2 pound increments, there are other models which are smaller and larger. I also bought a couple of "Battlefield" torque wrenches, preset one shot Torque wrenches adjustable via allen key in the handle, these are covered and fully weathersealed in plastic. I set these via the Acratorque at important torque limits (for example wheel nuts on the racer) which simplifies torqueing up when you're in a hurry.

 

Mick Richards

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Edited by Motorsport Mickey

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I used to use a similar device - but in miniature, when I used to work in microwave electronics (Decca Radar) we used them to setup torque spanners to tighten "SMA" coaxial connectors. It has a ¼" square socket into which you plugged an adaptor to the spanner size you needed.

 

Bob.

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If your torque wrench is reasonable quality, not battered and not too old it won't be far out.

With s cylinder head it is more important that the fixings are torqued equally rather than the actual value.

I have a Britiol and a couple of Norbars and an old bendy bar. None have ever been far enough out to require attention when I've checked them.

Edited by Drewmotty

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My first head gasket after the refurbishment blew while I was waiting for the recommended time for a retorque.

retorqued the next one with valve gear off at about half the time and it has been OK ever since (sorry don't have the recommended figures to hand and dinner is ready.)

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If your torque wrench is reasonable quality, not battered and not too old it won't be far out.

With s cylinder head it is more important that the fixings are torqued equally rather than the actual value.

I have a Britiol and a couple of Norbars and an old bendy bar. None have ever been far enough out to require attention when I've checked them.

 

Very dangerous and demonstrably incorrect.

 

Imagine you had a head gasket replaced by a garage or TR expert and they came out with such a statement when you subsequently had that head gasket blow ! Would you accept it as best engineering practice ? Why didn't Triumph specify say 50 lb ft rather than 105 lb ft ? as long as it's applied evenly ?

Torque values are specified by manufacturers because it's a quality control check upon work being carried out subsequent to the original build with the components, gaskets or stressed items requiring that amount of torque to work effectively as the manufacturer intended.

Check your torque wrenches every 12 months by whichever method you wish as long as it's reasonably accurate (within about 2%) and repeatable, but check them.

 

Mick Richards

Edited by Motorsport Mickey

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Mick, he did say "None have ever been far enough out to require attention when I've checked them".

 

I have a Norbar clicky type that must be 50 years old. When it was new I checked it against a friend's RAF-calibrated wrench, and the zero point was a little bit out, so I marked a new one. It has remained absolutely consistent since - I last checked it just a couple of weeks ago.

 

Pete

Edited by stillp

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