Why do modern car engines have different types of bolt type heads like Torx etc?

Some MG stuff had it the other way around with BSW/BSF heads on metric threads.
This Article gives an example, though I thing it occurred elsewhere too
https://svwregister.co.uk/technical/nuts-and-bolts-used-on-svw-engines

Bill

I think that's more testimony to you having developed a very measured driving style (and possibly doing the kind of journey that are kindest to clutches); than it is to the quality of modern vehicle clutches.

Average clutch lifespan is reported at between 30,000 for drivers in very congested cities, to 100,000 for drivers who drive predominantly outside urban areas, the OEM's target design life is usually for 60,000 miles.

Clutch on my car was still fine at 275,000 miles (ok, mostly motorway journeys, but still...) until the internal slave cylinder leaked and contaminated it. There was plenty of friction material left so I now think that modern clutches should last the lifetime of the vehicle if well treated.

In fact if I owned a car clutch plate manufacturer I'd be pursuing diversification of the business, global demand for them must be heading for a decline before too long.

When I worked the black cabs we got 100,000 out the first clutch with 90% town work then decided to change it so decent drivers do make a difference

Brand new car factory stuff also tends to be better quality and more longevitous than the garage OEM stuff you get at repairs time. Even the "branded" stuff can be not really that great

I suppose they don't want too much warranty stuff, know a lot of "Their" dealerships can be crap with dodgy mechanics, so putting decent gear in at the factory at the very start reduces the red side of the sales ledger

After our first major service at 60,000 she was never as good, especially on the fuel. Crap mechanics or "Branded" consumables dragging her down a bit

edit: One of the worst most useless mechanics I ever knew wound up at a major outlet after the oil pit he worked at closed down. Employers are desperate for "qualified" staff and don't ask many questions

The best garages tend to have one guy in charge who is great at his job, takes no prisoners with underperforming staff and seems to spend 18 hours a day in a boiler suit

Edited By Ady1 on 27/07/2023 10:15:34

My wife had a Morris traveller new in 1968 and it covered 187000 miles in around 20 years,in the engine & drive train nothing was replaced with exception of the prop shaft,due to a needle bearing seizing and spinning the outer race and wearing the housing,the bearing was not worn only too much grease caused the bearing to lock up,I think it was me being heavy handed with a Wanner grease gun. all ofthe ancillaries on the engine were not replaced and engine not decoked or worked on,though I stripped and cleaned the dynamo and starter motor at around 100 k miles. oil and filter changes as per book ie 3k miles plus all greasing,On the other hand the body was a disaster,a leak in the roof filled the rear passenger foot wells with water and it went back to Cowley,for repair,after registered letter was sent to the head of the company ,and later on the timber was eaten by a strange fungus and I replaced possibly 50% of the woodwork plus some rust dealt with , Really hammered by my wife on daily journeys to work of 40 miles regular servicing with good quality Castrol oil and grease .vehicles have improved in the last fifty years and engine performance is really good until the green nutters decide to abandon i/c engines, has any one thought out how umpteen million cars are going to get their electric cars charged from our already on the limit electricity supply.Getting back to fasteners and types of screw/bolt head when I worked on hard drives the small stainless screws used (hex skt head) produced miroscopic particles of stainless steel which destroyed heads and discs,as the hex drivers suffered wear and rattled in the screw heads, so the screws were changed to torqx heads ,the drivers lasted a lot longer so perhaps other industries have found that the torqx drivers are better, in recent years i have the found that mectric head sizes have changed there were spanners in my sets that I never used,and now most sizes are used.

Hi, my Astra clocked 144002 miles yesterday at the MOT, and there is no sign of pending failure of the clutch so far, and there is nothing in the service history to say it has every been changed. I've only driven it for 27155 miles.

Regards Nick.

Edited By Nicholas Farr on 27/07/2023 11:13:19

Odd hardware is nothing new.

Pre WW2, Morris used Hotchkiss engines, so the threads would definitely have been metric, but probably with Whit hexagones, to suit the spanners used by the UK mechanics.

In the late 60s, the clutch on the Gardner engine a Bristoll RE buses was fixed to the flywheel by 5/16 BSF threads. BUT trhe bolts had 5/8 A/F heads!

(Gardners were resolutely Whitworth standard, until they were taken over by Perkins. It took a long time, late 60s, before they would use shell bearings rather than metalled in the block and rod! )

The Bell Housing was clamped to the flywheel housing by nine 3/8 BSF bolts, the other three fixings were 3/8UNF studs!

Standardisation? Wha\t's that?

European manufacturers seem to prefer the "odd" numbered hexagon sizes, while japanese seem to prefer "even", for their cars

Renault used 12 mm A/F nuts to secure the carburrettor on the Renault 5 because there wasn't room for 13 mm hexagon nuts.

Howard

Edited By Howard Lewis on 27/07/2023 11:27:09

Agreed.

If the car is modern the owner has to be dissuaded from trying to fix his car. All are far too complex for even the service monkeys (I cannot call them anything else) at the dealers to fix. Looking under the bonnet of my 16 month old petrol engined I can recognise the battery. I think there is an engine under a lot of plastic ducting. As for finding and getting at the sparking plugs, forget it.

JA

One reason for mixed fastener heads on cars is the origin of the parts. A SAAB 9-5 can have a Fiat engine and GM transmission or Japanese for the automatic.
Another reason for not using Hex head or slotted/cross recess is tool wear. Torx, spline etc tool bits last much longer so less wasted time chaging them.

Robert.

Maybe it's because I started driving when modern engines were already a thing, and started repairing my own vehicles out of economic necessity in a way that pushed me to try things that felt out of my comfort zone...

But honestly, it's not nearly as hard as you might be deceived into thinking by appearances!

.

Sure there's a handful of tasks that need you to plug in a computer (and I do mean a handful), and some emissions system sensor faults which are easier to diagnose if you at least have a cheap code reader box from the auto factors.

But even on a modern, ECU controlled engine which is packaged very tightly indeed, there's nothing to stop a mechanically literate person making their own repairs, especially if they have reference to a good workshop manual (ideally the OEM's one), other than having the confidence to try.

When it comes to brakes, clutches, and tyres, the driver's care/skill will always make a far bigger difference than the parts...

I have to agree I have found a marked difference in quality between true OEM parts and aftermarket "pattern-parts", but by god do some manufacturers make it awkward to interact with their parts departments and the service offered is dire compared to using a decent auto-factors.

It's the fossil-fueled nutters you need to worry about Nigel! They're in denial about two much bigger problems: the oil supply running out, and man-made climate change.

The future of IC engines depends entirely on cheap oil. Pure fantasy to believe that mineral oil supplies are inexhaustible, the question is when demand for oil exceeds supply, not if. Prices are going to sky-rocket.

I'm not sure why the need for green is so difficult to comprehend. Is it just that folk can't bear to admit they got it wrong? Can't cope with any form of change? Fear? Vested interests? Or simply that the old ways are the best, even when it's obvious they aren't.

Over the last 40 years there's been a barrage of anti-green propaganda, most of which has proved wrong: green energy will always be expensive; green will never replace coal as a way of generating electricity; electric cars won't work; it's all too difficult etc etc etc. All deniers have managed to do is delay change, causing a lot of avoidable damage, whilst green engineering provides answers.

Although IC engines did a great job in the past, I'm afraid the end is in sight. They are not future proof. Given that transport is vital, I say it's essential to find alternatives to Internal Combustion pronto! Expecting oil to last for ever isn't an alternative.

Never mind where electricity for cars is coming from, ask where will the oil for IC come from in 30 years time? One of the two is a dead-end.

Dave

My old American lawn mower (no longer used but still in my garden shed) has Unified on the B&S engine and metric on the rest. Can't be to stop you servicing it as manual tells you how to. Its replacement (now also getting old) is all metric. Its manual tells me that it has no user servicable parts, strange how I have managed to keep it going for so long!
When I connected our cooker, I was surprised to find torx screws. I guess to stop me doing it, hah.I guess for some people that is a good thing. I overheard a conversation in a local shop. To the effect that a customer wasn't going to be ripped off by the store that sold him a new cooker (I agree the price he was quoting was a rip off). He asked the assistant if the cable he was going to buy was OK, she did admit that she hadn't a clue. Anyway he bought it and some earthing sleeve, he did know a bit. I thought to myself, they don't sell any cable suitable for a cooker, later went to check, he had bought 2.5 cable to wire his cooker - oops. By this time he had left the store!

The replacement of oil derived fuel for ICEs is already under way. For example look at P1fuels.

Hi Dave ,what sort of battery car have you got ?

Maurice

So where is the fossil fuel going to come from? Lots of alternatives

Biodiesel

Gaseous hydrogen, either in a fuel cell or burned in a IC engine

Methane made from hydrogen and CO2 extracted from the atmosphere. It's easier to keep methane in compressed state, bigger molecules don't leak as easily

Ammonia made from hydrogen and atmospheric nitrogen.

Synthetic petrol as being pushed by Porche

They all work, but Biodiesel takes vast areas of land which we need to grow crops for humans to eat, and the others require vast quantities of hydrogen, made using electricity, so you might as well just use the electricity direct by storing it in a battery.

We really ought to clamp down on long haul flights. My brother in law has had short trips to both Vietnam, Japan and Colombia this year. In comparison my pootling around locally in my car is chicken feed. There is no tax on aviation fuel.

I already try to use the train for long trips, it's cheaper than driving. My next car will be electric, when I bought the current petrol one 10 years ago electric were a much less practical option

As long as we have one part moving relative to another, there will be a need for lubrication. So "clean" electric cars, buses, and machines will still need oil, in some form another. Even bicycles!

Like it or not, in many cases that will mean that nasty black stuff that comes from far underground after it has been processed.

Sure, we can utilise vegetable oils (Castrol R so beloved of vintage car enthusiasts ), or we will need to be pretty good at synthesising oils to replace / replicate mineral oils.

So maybe there will an extended future for North Sea oil rigs and Saudi Arabian wells?

Howard

Edited By Howard Lewis on 27/07/2023 17:09:55

Doesn't matter what I drive Maurice: it's what's happening in the world that we need to worry about. Forty years of anti-green sentiment were badly wrong, so what next? Sadly Car Huggers are the problem, not Greenies.

I say transport is important. Therefore when the evidence says IC is on the way out, it's time to find an alternative.

No-one ever fixed a physical or economic problem by denying it!

Not all is lost. Providing transport without relying on cheap oil is an engineering problem that can be tackled. Bad news for petrol-heads maybe, but I don't care what the technical answer is provided it keeps the economy moving.

Belief systems shouldn't be allowed to get in the way. There are no sacred cows in engineering. If one sneaks in, it has to be slaughtered.

Dave

I will never own or drive an electric vehicle, my wife and I are financially comfortable with our pensions but there is no way we could justify the over priced EV's, I couldn't tow with one, without spending stupid money, and I doubt anybody would build an electric Renault Kango with a ramp and lowered floor as there would be nowhere to put the batteries so my wife would be totally housebound. We live in a village where the local bus companies don't know what a regular bus service is so when my Renault and Subaru give up the ghost so will we.

Martin P

This has wandered a long way off topic.

Dave

I live on the edge of a very rural area. The local politians are doing their best to stop the use of all cars, new and old. At the same time they are closing down the local bus services, replacing them with a half baked scheme that no one understands using transport that can be called by a smart phone. Really they want us to walk or use pedal bicycles. For lots it will take longer to get to the local city than it did 150 years ago.

This has nothing to do with engineering.

JA