IET Article - Car engines to increase in size following VW emissions scandal

[Tamworthbay]

That is irrelevant, the comment was about having to rev the nuts of a bike engine, as I said it only seems that way as some people aren't used to high revving engines. The vtech engines are the same in that you need to keep them spinning to keep the power up. The power and torque is there it's just delivered differently.

 

Power is power and torque is torque, the engine stats don't change if you put a fat person in a car/ on a bike!

[Dave_Q]

That is irrelevant, the comment was about having to rev the nuts of a bike engine, as I said it only seems that way as some people aren't used to high revving engines. The vtech engines are the same in that you need to keep them spinning to keep the power up. The power and torque is there it's just delivered differently.

 

Power is power and torque is torque, the engine stats don't change if you put a fat person in a car/ on a bike!

 

Sorry but that means about as much as "Brexit means Brexit"

 

 

Torque is indeed torque, something which most motorbike engines have not a great deal of, whereas power is the rate at which torque is produced.

 

Torque is the size of the shove, power is the total work done. 

 

For an analogy, if you had to hammer something large into the ground, torque is the size of your hammer, power is how far you hammer it in in total.

 

You can get the same power overall by hammering lots with a small hammer, personally for a big job like pushing a car along I'd normally go for the big hammer and hit it once.

 

 

Not a dig by the way, but bike engines are just not ideal for everything, to get back round to the original point of the thread, how many Co2s and mpgs is a bike engined Caterham doing @ 70 on the motorway compared to a Toyota powered one with an equivalent peak horsepower?

 

 

 

I think we're probably coming to the end of the days of the power race and the 0-60 time, in a generation or so people will probably have realised that you only need about 40bhp to sit at 50mph on a "smart" motorway, whether that's delivered by hybrid, electric, or a plastic 2CV equivalent, who knows.

[Tamworthbay]

Sorry but that means about as much as "Brexit means Brexit"

 

 

Torque is indeed torque, something which most motorbike engines have not a great deal of, whereas power is the rate at which torque is produced.

 

Torque is the size of the shove, power is the total work done. 

 

For an analogy, if you had to hammer something large into the ground, torque is the size of your hammer, power is how far you hammer it in in total.

 

You can get the same power overall by hammering lots with a small hammer, personally for a big job like pushing a car along I'd normally go for the big hammer and hit it once.

 

 

Not a dig by the way, but bike engines are just not ideal for everything, to get back round to the original point of the thread, how many Co2s and mpgs is a bike engined Caterham doing @ 70 on the motorway compared to a Toyota powered one with an equivalent peak horsepower?

 

 

 

I think we're probably coming to the end of the days of the power race and the 0-60 time, in a generation or so people will probably have realised that you only need about 40bhp to sit at 50mph on a "smart" motorway, whether that's delivered by hybrid, electric, or a plastic 2CV equivalent, who knows.

perhaps it makes more sense when on the same page as the other comments, the point was that torque and power stats don't change if the vehicle the engine in is heavier or lighter. The amount of power and torque produced is a function of many aspects of the design but cannot in any way be affected by what the engine is fitted in. The comment was that bike engines are only good in very light cars. A bike engine like the BMW 1000r that produces 200bhp and about 100ft/lb of torque would be as good as a similar spec car engine (if such a thing existed) but the way it delivers it may be different as bike engines have been built to be high revving for many years in a way car engines generally aren't. But none of that affects the numbers.

[danthecapriman]

I'm going to look at this very simplistically.

 

My Mercury is a very big heavy car. To make it move and perform it's intended purpose it has a very large multi cylinder low revving engine. Job successfully jobbed. As a bonus, it's very very unstressed so will do that job for a long time day in day out.

 

Now, if I were to remove that engine and put a fast, high revving small capacity bike engine in that same car I doubt very much it'd last long enough to even complete even one journey! To make all the weight of my car move I'd have to give that wimpy little engine a right thrashing, this would also make it's fuel efficiency suffer. It also wouldn't be able to do the job the car was intended for and wouldn't last anywhere near as long. It would be taking a high output small capacity engine in a very highly stressed situation, making it work very hard. Probably too hard.

 

Bike engines are great, in bikes. Car engines are great in cars. They are totally different types of engine intended for completely different purposes. I don't think it's really anything to do with engineering excellence tbh.

If so then I'd say car engines may be a bit more crude and basic but they are better overall because they can take more abuse and last longer?

For me, I think a large capacity, multi cylinder engine that doesn't have to work very hard and lasts indefinitely is the best solution.

[Tamworthbay]

But if you fitted a bike engine with the same power and torque as the existing engine then it wouldn't make any difference except that the delivery may be at a different point in the rev range. You aren't thrashing an engine if it has been designed to do high revs but a bike engine in a yank tank would sound more than a little strange. An internal combustion engine doesn't know what it's fitted to.

[danthecapriman]

No, but if there was a 'bike' engine the same capacity and size as my V8 then it wouldn't technically be a bike engine as it would never fit on a bike.

 

You can't just take any old engine, fit it to any old vehicle and expect it to cope. I know of a locomotive type that was fitted with a marine based engine from new.

As a marine engine it was fine. But as a train engine it was shit. They couldn't cope with the constant speed variations, gradients and varying weights it was expected to pull so they frequently blew up. Yet the same engine fitted in a boat was fine as it just sat at fairly constant speeds doing the exact same thing every day.

It's the same with cars, mine has a truck engine in it because that's the best thing for doing the job it's intended for. Likewise fitting a tuck engine to a bike (somehow!?) wouldn't work. It'd be hilarious but it wouldn't work terribly well as a bikes intended purpose.

 

Someone mentioned pinto engines earlier. Crude it might be but it's a bloody good engine. They went in cars, vans, small railway vehicles, pumps, Gennerators sets, boats etc etc, plus it's cheap and easy to fix. Far far more than an S2000 engine. The S2000 engine is more powerfull and more advanced but it's good in a sports car not so much for the other things the pinto has been used for.

 

There's a good reason why all cars, bikes, vans, trains, boats etc aren't fitted with the same engines. What works in one won't necessarily work in all.

[5speedracer]

I recall reading somewhere that two strokes cannot be made to burn efficiently when the pot exceeds 125cc. That would equate to building V8 1ltr engines............oh yes..........wonder if anyones ever done it ?

Moto Guzzi V8 racer....

 

https://youtu.be/rdxI3faucvM

 

Sent from my X17 using Tapatalk

[Mr_Bo11ox]

A bike engine like the BMW 1000r that produces 200bhp and about 100ft/lb of torque would be as good as a similar spec car engine (if such a thing existed) but the way it delivers it may be different as bike engines have been built to be high revving for many years in a way car engines generally aren't. But none of that affects the numbers.

 

It does affect them, in a big way. The very fact that bike engines are high revving means that, relative to car engines they achieve their power numbers via lower torque numbers hit more frequently per unit time, whereas car engines need to have bigger torque numbers achieved at lower speeds to haul a big steel bodyshell away from the lights. These car engines basically could not achieve 12,000 rpm if they wanted to, this is due to their architecture. They are different designs with different objectives.

[RoadworkUK]

 

A bike engine like the BMW 1000r that produces 200bhp and about 100ft/lb of torque would be as good as a similar spec car engine (if such a thing existed)

Not in a car. This is why BMW keeps its car engines in its cars and its bike engines in its bikes, except in the i3 REx range extender thingy. And in this case its two-pot is used purely to generate electricity and has no mechanical connection to the wheels anyway.

 

BMW, in many ways, knows what it's doing.

[cort1977]

Telling car makers that they now have to comply with emissions testing on the road, on randomly selected similar-spec cars straight off the production line, in real time conditions, at random intervals if necessary, would be no harder to mandate than Euro 6 or whatever.

 

Respectfully, I disagree with you totally.   That is just not the way a workable regulatory regime is achieved; it would never even reach a draft legislation stage because it is impossible to make 'emissions testing on the road' a consistent and fair process.   I say this as an engineer who regularly deals with compliance issues around government regulations.

[bigstraight6]

Leaving motorbike engines aside and going back onto the original topic, I'm guessing that the coming increase in engine capacity will be needed to offset the drop in output due to even more emissions controls on these engines....

[RoadworkUK]

Respectfully, I disagree with you totally. I say this as an engineer who regularly deals with compliance issues around government regulations.

Respect accepted, thanks. As an engineer dealing with compliance issues it would be interesting to hear your opinion on the VW emissions issues. The way I see it, yes, they cheated and should have the book thrown at them.

 

However, my gut tells me that they cheated at a test that doesn't really mean anything anyway. As far as I know nobody in the world tests emissions or economy on diesel cars in a way that will reflect the way they're actually driven.

 

Some people buy them for economy but an awful lot buy them for that torquey shove you get on acceleration. And there's no way you'll get that feeling while complying to the clean-exhaling ideals that the tests aim to govern. Foot to the floor, I'll bet those horrible, cheating VWs are no worse than the equivalent, albeit test-compliant, BMW.

 

Although I have absolutely no idea why it bothers me.

[mat_the_cat]

It's the same with cars, mine has a truck engine in it because that's the best thing for doing the job it's intended for. Likewise fitting a tuck engine to a bike (somehow!?) wouldn't work. It'd be hilarious but it wouldn't work terribly well as a bikes intended purpose.

 

Loosely a 'truck' engine...

 

[RoadworkUK]

Loosely a 'truck' engine...

That looks agile*.

 

Nice though.

[danthecapriman]

Loosely a 'truck' engine...

 

https://www.youtube.com/watch?v=ANwiN2jAa3s

Does look good fun, but it's a one off probably home built contraption. It doesn't look like it'd handle very well or be easy to ride though...

As a motorbike it's not a good mode of transport, it's a toy for fun.

 

I bet the riders knee gets a bit warm too.

 

I'd still love a go on it though!

[Guest Hooli]

Yes but can a bike motor make the same amount of torque and do 200k miles before the top end needs a rebuild?

 

 

My bike gives 123bhp & 98lb/ft. Sounds like a quick festia sized car to me. 108k so far & just normal servicing.

[warren t claim]

 

If only we had a shiter that had driven a bike engined car.

[garbaldy]

I took the blackbird engine back out my starlet but it was a proper hoot.

[Richard]

There have been bikes with the Citroen GS engine, and I believe a later model could be had with an XUD.

[martc]

There have been bikes with the Citroen GS engine, and I believe a later model could be had with an XUD.

 

Munch Motorbikes used NSU car engines to much critical acclaim.

 

The Van Veen used the Citroen GS Birotor Comotor wankel engine

 

The Quaser (along with numerous tatty trikes) used the Relaint engine

 

And even Brough made an Austin 7 engined bike (actually trike because it had two rear wheels very close together)

 

And I'm sure there will be many more examples.

[Richard]

I think the one I'm thinking of was called the BFG Odyssée.

[martc]

I think the one I'm thinking of was called the BFG Odyssée.

 Spooky - I was reading a copy of Motorcycle International from the late 80's not so long ago and they road tested a BFG, but it had a diesel engine in it (the same series as fitted to Citroen AX's) - overall a good review but the ground clearance was horrendous.

[lisbon_road]

For Roadworks UK, if you read the original paper that picked up the VW issue, they tested three cars.  One was a BMW with adblue NOX control system, which did really well with only occasional drifts over the limits and the other two were VWs which consistently failed.

 

When the tests were expanded to other cars, plenty were poor even if they did not include the defeat device system.  But the original test with the BMW - I think an X5, I'm doing this from memory - had shown that a system could be made to work, in manner that showed on the road testing giving results close to a laboratory test, which the testers pragmatically stated was all that could be expected.

[RoadworkUK]

For Roadworks UK....

 

Yeah, I read that the other day ( that's why I'm staying quiet now).

 

Still Seems appallingly wasteful and environmentally irresponsible to crush tens of thousands of recently-built cars whatever the "justification".

 

Interestingly, the American SFTP US06 programme does at least seem to incorporate hard acceleration and engine load, while our own New European Driving Cycle really doesn't.