240 General: New (to me) 1980 Volvo 244

[Clifford Pope]

Torque has the dimension of force X distance, and is expressed (in imperial) as ft.lb. Thus 5 ft.lb equals for example 5 lb pulling on a spanner one foot long.
Or it could be 10 lb on a 6" spanner or 2 1/2 lb on a 2 ft spanner. You could actually hook a spring balance onto a ring spanner and pull to the required force.
Lb/ft would have the wrong dimension and be meaningless in this context.

[Othen]

Originally Posted by Laird Scooby

My left headlight wiper salutes you for your efforts Alan!

Joking aside, a very productive day! Well done! Another little "tidy and make good" job that will improve the car overall ticked off the list!

I see you have a similar problem Dave. With older cars I think the trick is to know when to stop chasing diminishing gains. Getting both washers/wipers working more or less right probably only took an hour or so, and the only cost was £4 for a new washer T junction/valve. The only way of making this dead right would be to acquire another motor for the passenger side, which might be at least 30 years old and could have problems.

I’m really pleased with myself for ticking off this little job, the easy way out would have been to just remove the two wiper/washers completely, but I’m pleased I bothered to get them working again - the Royal Barge is that little bit closer to the way it came from Gothenburg.

I’m fortunate in having plenty of time to sort out these little issues on the Royal Barge, if I was paying for someone to do a proper restoration sorting out this little problem might have cost £300 in time and new parts.

Alan

[Othen]

Originally Posted by Clifford Pope

Torque has the dimension of force X distance, and is expressed (in imperial) as ft.lb. Thus 5 ft.lb equals for example 5 lb pulling on a spanner one foot long.
Or it could be 10 lb on a 6" spanner or 2 1/2 lb on a 2 ft spanner. You could actually hook a spring balance onto a ring spanner and pull to the required force.
Lb/ft would have the wrong dimension and be meaningless in this context.

I think we all agree Clifford: the dimensions for torque are force x distance, not force per unit distance. That was just a little slip above, and of no significance.

Alan

[Laird Scooby]

As the function of lb/ft and ft/lb is mathematically communicative, it doesn't actually matter. English convention states lb/ft, US convention states ft/lb as a 5 ft lever with a 1lb weight on it would have the same torque as a 5lb weight on a 1ft lever.

It's simply how the units are expressed according to the convention of the originating country.

The only confusing one is Nm in foregin countries. If it was kg/m then at least it would have some sort of simlarity to the rest of the planet!

[Clifford Pope]

Originally Posted by Laird Scooby

As the function of lb/ft and ft/lb is mathematically communicative,

But it's not "pounds per foot" as expressed by lb/ft, but "pounds X feet" as expressed by lb.ft or ft.lb. As I said, they are different dimensions.

One's division, the other's multiplication. The order doesn't matter in multiplication, x.y = y.x, but x/y is most definitely not equal to y/x.

[Laird Scooby]

Originally Posted by Clifford Pope

But it's not "pounds per foot" as expressed by lb/ft, but "pounds X feet" as expressed by lb.ft or ft.lb. As I said, they are different dimensions.

One's division, the other's multiplication. The order doesn't matter in multiplication, x.y = y.x, but x/y is most definitely not equal to y/x.

We're talking at cross purposes over the method of annotation though. We all understand the principles of torque and while i agree with you purely on the annotation aspect, it has (as far as i've always been aware) become acceptable to use the"/" purely to separate the ft and lb letters.

On a maths paper, 3.3.3 = 27 whereas 3/3/3 = 1/3 (0.33333) but regarding torque, many people would use lb/ft in exctly the same way as lb.ft.

One of those anomalies i doubt we'll ever get to the bottom of and as we all know what is meant, not worth arguing over.

[Othen]

Originally Posted by Laird Scooby

We're talking at cross purposes over the method of annotation though. We all understand the principles of torque and while i agree with you purely on the annotation aspect, it has (as far as i've always been aware) become acceptable to use the"/" purely to separate the ft and lb letters.

On a maths paper, 3.3.3 = 27 whereas 3/3/3 = 1/3 (0.33333) but regarding torque, many people would use lb/ft in exctly the same way as lb.ft.

One of those anomalies i doubt we'll ever get to the bottom of and as we all know what is meant, not worth arguing over.

With great respect Dave, Clifford is absolutely right about this one. The only correct units for torque are ones of force x distance (so lbf.ft, lbf.in, N.m, KGf.m - it would not make any difference whether one used ft.lbf, m.N and so on because multiplication is commutative, but the convention is generally the other was round).

It is never right to use the divide operator '/' - because that would mean 'force per unit distance' (like Km/h is kilometers per hour), which is not what is being expressed at all. One will never find torque quoted in lbf/in, lbf/ft, N/m in authoritative texts - but always as lbf.in, lbf.ft, N.m and so on.

I absolutely agree that this is not worth arguing over - but Clifford is still right :-)

Best wishes,

Alan

[Laird Scooby]

Originally Posted by Othen

With great respect Dave, Clifford is absolutely right about this one. The only correct units for torque are ones of force x distance (so lbf.ft, lbf.in, N.m, KGf.m - it would not make any difference whether one used ft.lbf, m.N and so on because multiplication is commutative, but the convention is generally the other was round).

It is never right to use the divide operator '/' - because that would mean 'force per unit distance' (like Km/h is kilometers per hour), which is not what is being expressed at all. One will never find torque quoted in lbf/in, lbf/ft, N/m in authoritative texts - but always as lbf.in, lbf.ft, N.m and so on.

I absolutely agree that this is not worth arguing over - but Clifford is still right :-)

Best wishes,

Alan

I agree Alan, i did say he was right in the post, i'm just pointing out that it seems (like many other things) to have "slipped" and become accepted. In definitive/authoritatative texts, you're absolutely right, it is expressed correctly and reading back on my earlier post (last night) i was not as explicit as i should have been - my fault!

[Othen]

Originally Posted by Laird Scooby

I agree Alan, i did say he was right in the post, i'm just pointing out that it seems (like many other things) to have "slipped" and become accepted. In definitive/authoritatative texts, you're absolutely right, it is expressed correctly and reading back on my earlier post (last night) i was not as explicit as i should have been - my fault!

You right Dave, I've seen people using that notation a few times.

I'm pleased to say the oil leak is sorted. I took the Royal Barge out for some food shopping yesterday, and drove far enough to get it up to temperature. Last night I put a drip tray with a piece of clean card inside under the car and this morning - it was clean.

I'm really pleased with that outcome - oil leaks are not really acceptable these days - and it must have irritated the PO.

best wishes,

Alan

[Laird Scooby]

Great news on the oil leak Alan!