Engineer/mechanic advice requested please

[Tex 36,817]

Imagine you bought a new washing machine, let’s say a Samsung (good reputation) and, say, three months in you started detecting a leak onto the kitchen floor. The engineer comes out, clatters about a bit and then says “Cor blimey, you won’t believe this, but them silly sods at the factory didn’t put the main gasket in!”

 

Would you get all weepy? Start gnashing your teeth? Worry about the future value of your machine? Of course not! You’d let the guy repair it and think no more about it.

 

A washing machine has a motor that spins by burning electricity. A motorcycle has one that spins by burning petrol. They’re, essentially, the same thing.

 

 Now, I like my Triumph better than any machine I have had for years. Much more than, say, my car. Or my fridge. I even have a name for it (first time ever). If it goes wrong it’s under warranty. If I still have it after the warranty expires I will fix it myself.  It’s a motorcycle. I love owning it and riding it. But it’s not the most important thing in my life. 

 

Remember, it feels nothing for me. It doesn’t wag it’s tail when I open the garage door. Doesn’t sit by the front door with a hopeful look on it’s face..

 

You may (with some justification) claim I’m not an ‘enthusiast’. If that means lying awake at night worrying over trivia like gaskets then I’m glad I’m not.  

[fred_jb 10,265]

Tex - you are not allowing for the different relationship a man has with his bike compared with his washing machine!  The later is truly an appliance. We bought a Samsung with a five year warranty, and I think it's coming up to 8 years old now and still going strong (will probably break now I've said that).  I appreciate it but don't feel any further bond.  In contrast, I think bikes and to some extent cars are different , even if only used for commuting.  You are in physical contact with them, your safety, even your life, can depend on them performing well and predictably, and you go through adversity and adventures together.  It is then not surprising that however illogical, people feel more of an attachment and therefore probably feel more let down by the manufacturer if a fault is found, and the pride and joy can no longer be seen as perfect, especially if there are nagging doubts about a repair.

 

I find it interesting how there is such a split on the forum over this issue between those who say it's nothing, been fixed, get over it, and those who would take such a thing more personally, and be more concerned about potential future implications.  Maybe you have been much more exposed to equipment like race bikes blowing up and being repaired, so tend to see it as no big deal, and maybe that was mostly stuff which you had no personal financial investment in, so further reducing any emotional involvement.  Some of us however, and I would include myself in this, feel more concerned about this sort of thing.  For example it is only because it is still under warranty that I don't fret too much about my GS breaking - once the warranty expires I will definitely worry more, and be concerned about a major fault being a financial burden to fix, and possibly reducing the residual value of my "investment".  It's not even as if I am mechanically naive, I've had engines apart, swapped engines out of cars, etc, but these days a lot of stuff is so complex with embedded electronics that even someone with lots of experience can feel a little helpless and exploited should things go wrong.

[Morph 257]

A long thread this.. and clearly one that brings out differing opinions.  As a noob, if this happened to me, I'd forever be thinking "if they forgot something as basic as the gasket (why didn't it leak pretty much immediately in the basic ride test??) what else wasn't adequately checked?"  - I know that's not logical, but it would be my fear.

 

I've also learned that some people go through lots of bikes!  I am pretty much the opposite (for now) - same with cars.  I don't have any relationship with the cars - they are just tools.  I do like the bike though.  No name yet 

[fred_jb 10,265]

11 minutes ago, Morph said:

A long thread this.. and clearly one that brings out differing opinions. 

Yes - but typical of this excellent forum, a civilised discussion has ensued between people of different opinions without World War III breaking out.  On the UKGSer forum the trenches would be dug, tin hats on, and you would have heavy artillery fire, in the form of personal abuse and bad language, being exchanged.

 

 

Edited November 23, 2017 by fred_jb

[Tex 36,817]

3 minutes ago, fred_jb said:

in the form personal abuse and bad language, being exchanged.

 

That was my next step!  

[Tex 36,817]

52 minutes ago, Morph said:

"if they forgot something as basic as the gasket (why didn't it leak pretty much immediately in the basic ride test??) what else wasn't adequately checked?"  - I know that's not logical, but it would be my fear.

 

A fear shared by many, obviously.  

 

How did the gasket get ‘missed’? Screwed if I know. Honest truth.

 

Why didn’t it leak straight away? Ah, I am on more secure ground here. Thankfully.

 

First, we need to ask ‘what does a(ny) gasket do?’ Answer it seals two adjoining surfaces to fill any machining imperfections and create an oil/water/combustion proof seal.

 

It should be bourne in mind that some older designs actually didn’t include a head gasket at all. The cylinder and cylinder head would be lapped together using grinding paste. The head gasket is just a convenient way to get a seal.

 

The machining on the Honda (all Hondas) is top notch. So good, in fact, that the two surfaces clamped together perfectly well. We know that because the engine not only started and ran, but ran well for 1800 miles. 

 

Combustion gas never leaked into the water jacket and pressurised the cooling system. Oil or water never leaked into the combustion chamber and billowed out as smoke or steam. Everything was well. A bit of an oil leak to atmosphere. Unusual today but once commonplace, even with gaskets.  

 

What about the projected life span of the engine? Why would it be any different to normal? It ran for a while with a tiny increase in compression. Big deal (not). Everything was lubricated as it should have been (unless you can prove different?) and all is well ‘down below’. I would bet money on it. 

 

‘The secondhand value has reduced’. Seriously? It doesn’t work like that. Never has. In the (unlikely) event of a question being asked - yes it had a new head gasket at 1800 miles. Big deal. Runs perfectly now.

 

The ‘relationship’ between man and machine has been spoiled. Can’t really say, I buy motorcycles, not marry them.

 

”Repeat after me, I, call upon those persons here present to witness that I, Simon Davis, take thee, Percy Bonneville, to be my lawful wedded...”

 

Any of you folks who have built ‘relationships’ with your bikes - here’s something to consider. If you fall through the ice into a frozen river don’t expect the bloody thing to jump in and try and pull you out. It’s just going to stand there. Inert. Lifeless. It’ll remain there until someone turns up with a key. Or until it rots away.  It really is ‘just’ a machine.

 

 

[Trev 18,644]

6 minutes ago, Tex said:

 

The ‘relationship’ between man and machine has been spoiled. Can’t really say, I buy motorcycles, not marry them.

 

”Repeat after me, I, call upon those persons here present to witness that I, Simon Davis, take thee, Percy Bonneville, to be my lawful wedded...”

 

Any of you folks who have built ‘relationships’ with your bikes - here’s something to consider. If you fall through the ice into a frozen river don’t expect the bloody thing to jump in and try and pull you out. It’s just going to stand there. Inert. Lifeless. It’ll remain there until someone turns up with a key. Or until it rots away.  It really is ‘just’ a machine.

 

 

 

...... and what have you named your Triumph Tex? 

[SteveThackery 3,090]

8 minutes ago, Tex said:

 

Any of you folks who have built ‘relationships’ with your bikes - here’s something to consider. If you fall through the ice into a frozen river don’t expect the bloody thing to jump in and try and pull you out. It’s just going to stand there. Inert. Lifeless. It’ll remain there until someone turns up with a key. Or until it rots away.  It really is ‘just’ a machine.

 

 

Which reminds me of one of my pet "hates": the habit some people have of anthropomorphising their machines.

 

I read on the Enfield forum someone asserting "My machine is happiest at 55mph", an assertion which usually puts me immediately into "Angry of Nottingham" mode as I hammer out a disparaging response on my keyboard.  Engines are never happy.  Engines are made from steel and aluminium, materials well-known for their reluctance to emote.  Engines are just bits of metal subject to stresses either within, or without, their design parameters.  It works or it blows up, but it is never sad, nor happy.  Anyone who sits on a motorbike and says "It's happiest at 55mph" or whatever is fooling themselves twice.  Firstly, there's no way you can tell from the seat how close the big end studs are to their yield point, or measure the g-force experienced by the inlet valves, or calculate the mean velocity of the piston; you just can't do it and it's silly to think you can.  Secondly, there is no "happy" - just a complex series of forces, stresses, strains, velocities, accelerations, all of which boil down to this: it's either inside, or outside, the design parameters.

 

I'm with Tex on this: I acknowledge that people sometimes think they have a "relationship" with their bike, but be assured it is entirely one way.  Your bike is cold-hearted and indifferent.  I, nevertheless, am fond of some of my possessions; mostly watches and engines, sometimes cars and bikes, certainly my TV and my computer.  But fondness is all it is.

[Spindizzy 7,109]

If you substitute the word happy for smooth and unhappy for horrid vibes it works, That's not anthropomorphising, its semantics.

 

My old PD Fabia diesel was 'happy' in 4th below 55 and 'unhappy' between 1200-1350 rpm

 

Actually it was smoother and quieter as above or rattled like a bag of spanners likewise. Semantics

 

 

 

 

 

Edited November 23, 2017 by Spindizzy

[SteveThackery 3,090]

6 minutes ago, Spindizzy said:

If you substitute the word happy for smooth and unhappy for horrid vibes it works, That's not anthropomorphising, its semantics.

 

Except that people use their "happy" claim to justify how they use their bike (to avoid going faster, for example), claiming it is somehow harmful to the engine if it isn't "happy".  Seriously, people really do say "I don't like pushing my bike much above 60; it's much happier at 55".  Which is silly nonsense, of course.  

 

The only possible response is "It's steel and aluminium, it can't be happy or sad; and in any case, how would you know?"

 

You are right - it seems to be something to do with finding a speed at which the various vibrations modes happen to cancel out at the seat and handlebars, rather than anything more meaningful.

[Morph 257]

1 hour ago, Tex said:

 

<snip - but appreciated and agree with pretty much all your response :-) >

 

First, we need to ask ‘what does a(ny) gasket do?’ Answer it seals two adjoining surfaces to fill any machining imperfections and create an oil/water/combustion proof seal.

 

 

I think what is surprising me, is the pressure inside the engine must be pretty high (during combustion) so I was expecting seepage immediately, as that oil, under what I thought was high pressure, would slip past even the tightest of seals... without... a gasket or paste.  In many days past I had a Chrysler Alpine (yep, and an Orange one to boot) that was donated to me by my father .. it had a blown something and leaked oil all over the engine.  I cleaned the engine and replaced the head gasket (er, had a bit of help) ... and test drove it.  I had seated the gasket ever so slightly imperfectly... it seeped very clearly, in the test drive of under 5 miles. Clearly as the bike in question wasn't delivered with oil all over the place, it was indeed machined to a much higher tolerance.  

 

Still. every time I read one of these threads it convinces me to leave some jobs to others.  I think I would rather spend the time enjoying the ride than spending years learning a smidgen of what you lot know!  Just have to work to pay someone else... but as was said earlier, keeps them in a job.  And I do the same with boiler servicing, and expect to be paid for my knowledge so.. all good for the economy.

Edited November 23, 2017 by Morph

[fred_jb 10,265]

1 hour ago, Spindizzy said:

If you substitute the word happy for smooth and unhappy for horrid vibes it works, That's not anthropomorphising, its semantics.

 

My old PD Fabia diesel was 'happy' in 4th below 55 and 'unhappy' between 1200-1350 rpm

 

Actually it was smoother and quieter as above or rattled like a bag of spanners likewise. Semantics

 

 

 

 

 

I agree, if you have any degree of mechanical sympathy you will get to know the operating ranges in which any machine works most smoothly and with the least apparent strain - i.e. where it is happiest!

 

Doesn't of course mean it will refuse to be lugged at low speed in a high gear or stop you revving the nuts off it in a low gear, if you really feel the need to do so.

 

 

Edited November 23, 2017 by fred_jb

[kayz1 2,928]

How come the factory computer that tests the engines did not pickup on the difference in the compression of this engine and the norm!! 

Cos a lot of engines today, the first time they are run is at the dealers on PDI..computer does all the calc's and says yes or no..

[SteveThackery 3,090]

1 hour ago, fred_jb said:

I agree, if you have any degree of mechanical sympathy you will get to know the operating ranges in which any machine works most smoothly and with the least apparent strain - i.e. where it is happiest!

 

 

"Mechanical sympathy" - it exists, I agree, but it is so unreliable it is no substitute for the laws of physics.  You talk about the machine working "most smoothly".  What does that actually mean?  The lowest level of vibration?  But what does that really tell you about the stresses and strains inside the engine?  Nothing, basically, because: a/ vibration is a normal by-product of all reciprocating engines, and b/ the engine is not isolated - it's in a complex system (the frame, cycle parts, etc) which has numerous complex vibration modes.  Sure, you may well find a speed at which the perceived vibrations are lowest due to some fortuitous cancelling-out, but what does that tell you about the engine?  Nothing!

"The least apparent strain".....  note that word "apparent".  Look, it's simple: there is a mathematical relationship between the stress on each part of an engine and the engine rpm.  There is also a mathematical relationship between the stress on SOME parts of an engine and the power it is producing.  "Apparent" has nothing to do with it; it's mathematics and physics all the way to the bottom.

 

Mechanical sympathy exists, I'm sure, but:

• it is unreliable, inconsistent and subjective;
• many people think they have it, when they haven't;
• there is no agreement on what "mechanical sympathy" actually is; 
• mostly you can't teach it, and you can't really test it;
• it won't get you a job designing engines;

....but yes, I agree, it's nice to think you have it.

 

[fred_jb 10,265]

1 minute ago, SteveThackery said:

 

"Mechanical sympathy" - it exists, I agree, but it is so unreliable it is no substitute for the laws of physics.  You talk about the machine working "most smoothly".  What does that actually mean?  The lowest level of vibration?  But what does that really tell you about the stresses and strains inside the engine?  Nothing, basically, because: a/ vibration is a normal by-product of all reciprocating engines, and b/ the engine is not isolated - it's in a complex system (the frame, cycle parts, etc) which has numerous complex vibration modes.  Sure, you may well find a speed at which the perceived vibrations are lowest due to some fortuitous cancelling-out, but what does that tell you about the engine?  Nothing!

"The least apparent strain".....  note that word "apparent".  Look, it's simple: there is a mathematical relationship between the stress on each part of an engine and the engine rpm.  There is also a mathematical relationship between the stress on SOME parts of an engine and the power it is producing.  "Apparent" has nothing to do with it; it's mathematics and physics all the way to the bottom.

 

Mechanical sympathy exists, I'm sure, but:

• it is unreliable, inconsistent and subjective;
• many people think they have it, when they haven't;
• there is no agreement on what "mechanical sympathy" actually is; 
• mostly you can't teach it, and you can't really test it;
• it won't get you a job designing engines;

....but yes, I agree, it's nice to think you have it.

 

I think it is a real thing, but obviously not very scientific and difficult to ascribe any degree of accuracy to - though it is fairly easy to detect a complete absence of it!  I am reminded of a friend many years ago in London who got a Mini as her first car. She basically treated the clutch as an on/off switch, and the accelerator pretty much the same.  The poor car had the gears rammed home, the clutch unceremoniously dropped and ran at full throttle most of the time, at least when it wasn't being emergency braked!  It was scary being a passenger and the feel and sounds of mechanical distress were unmistakeable.  From what I remember it didn't last long, though I don't recall what part of the drivetrain was the first to give up.

 

Probably modern vehicles are more tolerant of clumsy or hard use, but in earlier times, if they wanted them to last, people really did have to treat vehicles with a degree of care to allow for limitations in design and materials compared with today, and I think that is probably where the idea of mechanical sympathy came from.  My Dad tended to take this to extremes, in pursuit of both vehicle longevity and minimising fuel consumption, though I always thought he overdid it a bit by lugging the engine at excessively low revs in a high gear.  If I ever drove him in his car, which I did more as he got older, he would always be saying "there's another gear you know" if I didn't have it in top by about 40 mph!

[Guest bonekicker]

Perhaps being able to part exchange our women/man might be worth a try--changing to a different woman/man--would at first appear to be somewhat more perfect than the other--we are gentle--more understanding--read the new owners manual from start to finish to avoid any user mistakes--talk of love--run her in slowly-- oil and dine her--but then start listening for any different noises coming from her--they need the usual farkels -- power washed after every ride--spend time with her and start listening again--understanding her/his needs-------we soon start finding the little niggly bits--try to fob them off saying I can live with that-- But only to find one day the first argument about nothing as per usual--then go raving mad because you're not really listening--that just like your previous stead--the 2 year warranty does not cover breakdowns like this--road side assist is needed--taken back to garage for the counselors/ therapists--to have a diagnosis of the fault--only to find the head gasket on her/him is missing !!!! causing to much compression inside head camber--and who knows what unseen damage to new relationship--- would you consider another part exchange or just sell the stead -- and DIY in the future.    

[Andy m 23,540]

The pressure inside an engine is generally about 10 bar. Not much when you think air in a trucks reservoir is at 13 and that JCB on the back has oil at 250 bar. Engines have higher variation 0.1-10 bar 50 times a second versus 3 to 13 bar over a minute. They also meet nasty hot gasses as against a gently warm, hopefully clean fluid. It is still Victorian technology and pretty forgiving.

 

They will have spent hours working out how they missed it. The usual Japanese pokeoke is a tray with grooves/pegs/markings. Worker A checks the tray is empty by stacking it vertically to go to B, it won't fit if half full, B puts a gasket on with the nuts, head etc., his work station won't move until the weight is right, C fits the gasket . They are responsible as a team for making sure there are no bits on the floor when they swap jobs after an hour and the stock system will check they got through the right ratio of parts (or reported lost or broken ones) . This one was built at the second the fire alarm went off or something, they work to 5 in 10 million failure rates.  Their biggest problem is that the machine shop will have the flatness down to 10 microns using SPC, so most of them will seal without the gasket. EOL will pass it if it sealed for the five minutes it was on there. If you want ****, buy a Ferrari or Rolls Royce where some old boy fettles each bit to a fit that depends on what mood he's in and stays with each vehicle long enough to hide his mistakes.

 

Naming vehicles is a tradition going back to when even more people thought they were full of demons. The names are usually easier to remember that serial numbers. Using "happy" and "optimal" interchangeably I can live with. It can also be useful. When someone tells you the fault "it be wrong in the brain" you know you are dealing with an idiot and can adjust your response.

 

Andy

[Grumpy old man 4,677]

44 minutes ago, bonekicker said:

 -- and DIY in the future.    

What do  you mean?

[suffolk58 2,286]

In my job, I regularly meet drivers and riders who inform me that their car/bike is only "happy" when driven/ridden at speeds over the national limit.

[DaveM59 1,605]

7 hours ago, kayz1 said:

How come the factory computer that tests the engines did not pickup on the difference in the compression of this engine and the norm!! 

Cos a lot of engines today, the first time they are run is at the dealers on PDI..computer does all the calc's and says yes or no..

Possibly because the tolerance has more + than - as maybe a - indicates a leak or weakness where as a + indicates a good seal.

I fail to see what other damage could possibly have been done if the motor was actually running OK. The worst would have been if the oil was getting contaminated with water as far as the bearings are concerned but again, think how many engines blow a head gasket at some point in their life with such cross contamination and all that happens is it is replaced and the oil and coolant changed. No worries about other wear crosses most peoples minds so why in this case. It's just another blown head gasket, only there wasn't one in the first place.

[Trev 18,644]

1 hour ago, suffolk58 said:

In my job, I regularly meet drivers and riders who inform me that their car/bike is only "happy" when driven/ridden at speeds over the national limit.

 

ooer, have we met? 

[suffolk58 2,286]

I did wonder when I heard about your magnificent Mustang Trevor.

I once met a chap who claimed his three litre engined car was impossible to drive below 30 mph.

[Trev 18,644]

2 minutes ago, suffolk58 said:

I did wonder when I heard about your magnificent Mustang Trevor.

I once met a chap who claimed his three litre engined car was impossible to drive below 30 mph.

My Mustang is a bit lumpy at 30mph (actually it's a bit lumpy full stop!) but if I keep having to run it in because of replacement engines every couple of months then I won't have to worry about speeding too much 

[Tex 36,817]

All the really great engines operate over a wide rev range. That’s one of the basic requirements for ‘greatness’ (in my book). 

 

Engines that run run like a turd low down then ‘kick in’ when a magic figure on the tachometer is passed are the worst kind of hell. And their designers should go there! Do not pass ‘go’, do not collect £200.

 

And with modern design techniques and engine management there’s no excuse (at all) for anything but smooth, powerful and reliable engines. 

[Big Al 82]

I used to work in the car industry. Cars that are mass produced provide few issues, however now and again issues will arise when they do some of them we would call  “Friday cars” once an issue was found on a car the repair can cause more issues, this is because you are now relying on the person rebuilding the vehicle rather than the mass production processes. For me it all comes down who are the people working on your bike, rather than what Honda may want. If you have confidence in the mechanic then the replacement gasket would be OK, if you are unsure of the ability’s of the mechanic then swap the engine. If you think you will get a rushed job with shortcuts being taken, then go for a new bike.

 

Just my 4 penny’s worth.