VR6 History?

[MagicIan 0]

Had this conversation the other night with a mate who says the vr6 was originally designed to be diesel :gag:

 

I dissagreed with him which started a debate, i say if it was designed for wiesel then only the block would be the same as petrol and diesel internals would differ quite a bit? Engines are not my forte, but i can't see that he right.... please don't let him be right, i'll never hear the end of it!

[VR6 0]

Think you might be eating humble pie ;)

[Supercharged 2]

Yep - the RV6 was originally designed as an oil burner...

[paul20v 0]

Had this conversation the other night with a mate who says the vr6 was originally designed to be diesel :gag:

 

I dissagreed with him which started a debate, i say if it was designed for wiesel then only the block would be the same as petrol and diesel internals would differ quite a bit? Engines are not my forte, but i can't see that he right.... please don't let him be right, i'll never hear the end of it!

that would have made an intresting diesel thou , i wonder why they did not do it ,

enjoy your pie mate :grin:

[MagicIan 0]

:shock: Well i never.....

[yeti 0]

so does this mean we should all be thanking our lucky stars that we can run cheap Vmax petrol atm then :lol:

[aclwalker 3]

I wasn't aware of this. Is there a source for this info?

[craigowl 0]

Never mind - diesels will rule.

 

I have seen in my time very smoky, noisy lumps transform into state of the art power plants capable of 70mpg (and rising) from 1400cc with better performance (still rising, too) than that of 1600-1800cc 1970s sports cars/coupes which did only 27-32mpg. Basically, unless you are disgustingly rich or foolish with money, diesel may well prevail.

[aclwalker 3]

Never mind - diesels will rule.

 

I have seen in my time very smoky, noisy lumps transform into state of the art power plants capable of 70mpg (and rising) from 1400cc with better performance (still rising, too) than that of 1600-1800cc 1970s sports cars/coupes which did only 27-32mpg. Basically, unless you are disgustingly rich or foolish with money, diesel may well prevail.

True, but diesels almost all have turbos now do they not?

 

Would petrol engines not be far in advance once more if they all had turbos?

 

I get the impression that diesel is only starting to rival petrol in performance because they've accepted that they can't compete unless there's a turbo present. Maybe I'm wrong.

[dr_mat 0]

Actually IIUC the only aspect of the VR6 that was designed with this in mind was the use of timing *chains* rather than a rubber belt. Everything else on the AAA/ABV blocks was clearly designed for petrol.

 

There *is* a vr- diesel in the VW range, but it only went into the pointless cars - the tiguans and the tosspots and the vans.

 

And it has to be said, although I'm sure diesels WILL all but eradicate the petrol engine in our lifetime for the majority of drivers, they are far from paragons of virtue. They are still pretty shoddy in terms of the smoke they put out.

 

Like I've said many times before the petrol fuelled reciprocating piston engine is a design long overdue a complete rethink. The restriction of having to run at or near stoichiometric fuel/air ratio all the time ultimately prevents you getting much better economy than we are currently getting out of it. Get rid of the reciprocating pistons and you'll release MORE of the energy you burn, rather than using it to throw lumps of metal about, but you're still stuck with ~1:20 fuel to air.

[coullstar 0]

2 stroke and methanol is the future!!!

[craigowl 0]

"True, but diesels almost all have turbos now do they not?"

No rules saying you can't turbo and supercharge a diesel.

Perhaps someone can enlighten us as to why petrol engines cannot be developed for such gains.

 

dr_mat said:

"They are still pretty shoddy in terms of the smoke they put out."

 

Too right, Herr Doktor,

 

I attended an air pollution lecture by a top UK specialist in respiratory diseases and he said that the pm10 sized particles cost our nation billions of £ per annum for damage to health. :shock:

 

He also told us, that after revealing their findings, the government said "that is something we did not want to hear...".

 

I asked what was his view on the great increase in purchase of diesel cars, but he kind of bodyswerved giving a direct answer. It would appear we are in an era of indecision regarding our motoring future.

[dr_mat 0]

I get the impression that diesel is only starting to rival petrol in performance because they've accepted that they can't compete unless there's a turbo present. Maybe I'm wrong.

 

Look around mate! You don't see many high performance petrol cars that don't have turbos! A few: it's mostly Honda VTECs which get roundly criticised for having no torque, or it's large V6/V8 engines with truly epic fuel consumption.

 

And a 180bhp turbo diesel produces 50% more torque and uses 50% less fuel than a turbo petrol engine that's putting out the same amount of power..

 

Of course it's true to say that a non-turbo diesel versus a non-turbo petrol engine is not really a contest, but the diesel will use a tiny fraction of the fuel of the petrol engine, and it will do 90% of the same job, it just won't produce anything like the *power*. Torque outputs will be similar though.

[Kevin Bacon 5]

I've not seen any tangible evidence to support VW's intention to Turbo Diesel the VR6. As far as I can tell, it's just a myth. However, if you look closely at the VR6's component parts, the way it was constructed could easily run as a TDI.

 

TDIs need a strong block, and the VR6 definitely has that, and it has the necessary heavy duty crank and rod bearings with excellent lubrication....important when you're running 18:1 (or higher) compression ratio.

 

If you also look at how the engine is tilted forward, it gives you loads of room for a turbo at the back, with water cooling lines already in place.

 

It's crossflow too, another important consideration when turboing.

 

To build it as a TDI would have cost a huge amount of money, new rods, new crank, new pistons, new fuelling setup etc etc..... and the requisite testing and analysis would have delayed the VR6's introduction to the Corrado, which VW didn't want.

 

Actually IIUC the only aspect of the VR6 that was designed with this in mind was the use of timing *chains* rather than a rubber belt. Everything else on the AAA/ABV blocks was clearly designed for petrol.

 

Chains were used to provide the necessary chassis leg clearance in Corrado and Golf applications.

 

Chain driven drivetrain is common to a lot of engines and it's for packaging reasons rather than fuel type. A rubber belt can turn cams just as easily as chains.

 

Like I've said many times before the petrol fuelled reciprocating piston engine is a design long overdue a complete rethink.

 

It'll never happen :D

It's a brilliantly simple and effective design. Many complicated and expensive alternatives have come and gone over the years, but the piston engine is still here and popular as ever. You can't beat piston engines. That has been proven categorically I would say? Arguments about how efficient they are is neither here nor there because they're here to stay. And I'm glad because they have been central to car enthusiasts for decades.

 

I can't see people gathering around a car and enthusing over a DC motor, or some weedy looking rotary running on Olive oil.

 

I also can't see BMW's M3 and Honda's VTEC engines being replaced with crappy green alternatives. They are pivotal engines and nothing else will do.

 

Men and machines. Whilst the world is run my males, piston engines will remain :D

 

The restriction of having to run at or near stoichiometric fuel/air ratio all the time ultimately prevents you getting much better economy than we are currently getting out of it. Get rid of the reciprocating pistons and you'll release MORE of the energy you burn, rather than using it to throw lumps of metal about, but you're still stuck with ~1:20 fuel to air.

 

What's the alternative? It has to be cheaper and easier to implement and mass produce than a reciprocating engnie. It has to be massively more efficient, not just a little bit, and the buying public have to actually want it.

 

If not, then the powers that be simply won't bother.

 

And do you think OPEC will allow efficient engines to exist whilst there is still oil in the ground?

 

And diesel, LOL! Yeah it's come a long way and Audi and Peugeot have been doing Diesel publicity stunts for a decade.

 

But they still have narrow power bands, the cost of fuel is ridiculous, the engine blocks need serious strengthening, the soot they produce is dangerous and they sound awful.

 

They're getting better, compression ratios are lowering, meaning more revs and fuelling is getting clever.

 

VW's petrol TFSI engines are very efficient, as is the latest generation 1.8T engine. Just as quick as the TDI equiv', well, quicker actually, and hardly any thirstier in the REAL world.

 

TDIs as they currently stand produce their peak torque from 1300 to 3000rpm ish. Look at a stock Golf GTI. torque is there from 1800 to 5500rpm. I know what I'd rather have.

 

But the future for the next 20-30 years imo, is E85. Cheaper than diesel and petrol, and MASSIVELY cleaner than both and renewable.

So what's the waiting for? Red tape..... as usual.

 

One minute Brown is supporting Wind farms, and the next he's looking for oil in Suffolk to ease the crisis. What a feckin joke these mock green supporters are. Whilst they're feckin about with their propoghanda, thumbs up arses, the world isn't getting any cleaner.

 

E85 is ready to go NOW.

[dr_mat 0]

Chains were used to provide the necessary chassis leg clearance in Corrado and Golf applications.

Then I heard wrong.. :)

 

The restriction of having to run at or near stoichiometric ..

What's the alternative?

If I knew that I wouldn't be sitting here talking to you about it! ;)

 

And do you think OPEC will allow efficient engines to exist whilst there is still oil in the ground?

True: there's another pigopoly that the world should never have allowed to happen. They're sitting there shafting everyone and there's literally nothing we can do to stop it. Ignoring for the minute that arguments about oil dependency, OPEC have the power to reduce the price by increasing production. They choose not to, and frankly the rest of the world should be doing something about that.

 

And diesel, LOL! ... But they still have narrow power bands, the cost of fuel is ridiculous, the engine blocks need serious strengthening, the soot they produce is dangerous and they sound awful.

The narrow power band is not a problem in terms of propelling a vehicle, only in terms of "having fun". As you've said, this is all about boys and toys, and little or nothing about the use of suitable technology.

 

VW's petrol TFSI engines are very efficient, as is the latest generation 1.8T engine. Just as quick as the TDI equiv', well, quicker actually, and hardly any thirstier in the REAL world.

Sure in lean burn mode the FSi is pretty efficient, but they're also crap to drive (lurching in and out of lean burn mode) and when you open the throttle it's still 1:14.7 .. But that's not the point: the point is you (being a petrol head) wouldn't buy one, so that puts it in the same camp as the diesel.. ;)

 

And "hardly any thirstier"? Is that like "hardly any more poisonous? :) I know plenty of people who get 50-60 mpg out of their TDis and no-one who gets more than 40mpg out of any reasonably similar spec petrol engine. Take both cars into town and the difference is more stark: diesels use so much less fuel idling than petrol engines that the difference they make in traffic is much bigger.

 

But the future for the next 20-30 years imo, is E85.. and renewable.

It's also made from food! This is the big problem with "renewable" fuels. Everyone needs to eat, no-one needs to drive, so the logical choice is surely to burn things we can't eat .. So E85 and friends are pushing up the price of food. Which is fine for us rich countries, but the poor countries just get more shafted and have to support our right to be bloody stupid.

 

Anyway, I know that in reality you're right: nothing much will really change until we *actually* run out of oil; but I'd like to hope that we will collectively plan far enough ahead to make it a less painful switchover when the inevitable does happen and we find some alternatives before it's too late.

[Kevin Bacon 5]

LOL, another debate that could eat an afternoon and achieve nothing, but on this point though.....

 

Sure in lean burn mode the FSi is pretty efficient, but they're also crap to drive (lurching in and out of lean burn mode) and when you open the throttle it's still 1:14.7 .. But that's not the point: the point is you (being a petrol head) wouldn't buy one, so that puts it in the same camp as the diesel.. ;)

 

.....lurching? Which ones have you been driving?? I've driven most of the petrol and diesel MK5s and the only one that "lurches" noticably is the R32 because of it's horrid throttle mapping. Nothing to do with how it's burning fuel!

The GTI is a brilliant car. It handles, it rides well and the engine is superb. And being a Petrol head, I *would* buy a GTI..... for those reasons. I would also buy a diesel....so long as it's got BMW's 3.0 twin turbo D lump in it :wink:

[aclwalker 3]

"True, but diesels almost all have turbos now do they not?"

No rules saying you can't turbo and supercharge a diesel.

Perhaps someone can enlighten us as to why petrol engines cannot be developed for such gains.

Indeed. All I'm saying is that almost all diesels have a turbo, whereas only performance petrols have turbos. Then people erroneously think that diesels have come along a lot recently because they are comparing the performance of diesels (possibly with a light pressure turbo) with a normal bog standard petrol. It's not comparing like with like, and if petrols had light pressure turbos then nobody would buy diesels!

dr_mat said:

"They are still pretty shoddy in terms of the smoke they put out."

 

Too right, Herr Doktor,

 

I attended an air pollution lecture by a top UK specialist in respiratory diseases and he said that the pm10 sized particles cost our nation billions of £ per annum for damage to health. :shock:

 

He also told us, that after revealing their findings, the government said "that is something we did not want to hear...".

 

I asked what was his view on the great increase in purchase of diesel cars, but he kind of bodyswerved giving a direct answer. It would appear we are in an era of indecision regarding our motoring future.

The pollution from diesels is horrendous and we are constantly lied to by the government about this. Diesels produce massive amounts of lung-clogging particulates. There are moves afoot to mandate diesel cats (like petrol cats from 1992 onwards) but these particulates are a technical problem. How do you stop the particulates clogging the cat?

 

In my opinion, the reason that diesel is being pushed is because of the realisation that light sweet crude is running out and more and more of the oil is heavy and that is often sour (high sulphur content) which requires expensive refining. It's probably far easier to make diesel from this heavier oil than petrol, given that diesel is a heavier fuel.

[aclwalker 3]

I get the impression that diesel is only starting to rival petrol in performance because they've accepted that they can't compete unless there's a turbo present. Maybe I'm wrong.

 

Look around mate! You don't see many high performance petrol cars that don't have turbos! A few: it's mostly Honda VTECs which get roundly criticised for having no torque, or it's large V6/V8 engines with truly epic fuel consumption.

 

And a 180bhp turbo diesel produces 50% more torque and uses 50% less fuel than a turbo petrol engine that's putting out the same amount of power..

 

Of course it's true to say that a non-turbo diesel versus a non-turbo petrol engine is not really a contest, but the diesel will use a tiny fraction of the fuel of the petrol engine, and it will do 90% of the same job, it just won't produce anything like the *power*. Torque outputs will be similar though.

I am looking around, and the only petrol engines with turbos are performance cars, whereas almost any diesel has got at least a light pressure turbo, which in my opinion is to mask their woeful performance in order to fool the general public into buying them, because the ratio of light to heavy crude is becoming more biased towards the heavy end.

[Kevin Bacon 5]

Indeed. All I'm saying is that almost all diesels have a turbo, whereas only performance petrols have turbos. Then people erroneously think that diesels have come along a lot recently because they are comparing the performance of diesels (possibly with a light pressure turbo) with a normal bog standard petrol. It's not comparing like with like, and if petrols had light pressure turbos then nobody would buy diesels!

 

Yep, there's no finesse with TDIs. Cram as much air in as possible then simply meter in the required fuel. They are completely gutless with no turbo.

Because diesel burns at much lower temperatures than petrol, variable nozzle turbos can be used, which give massive torque at low rpms when the vanes are fully closed. That's what gives the TDI it's "Wow, this is quick" factor.

Variable nozzle turbos have only just made it to petrol engines now that the heat resisting technology has been sussed, the Porsche 997 being the first one. That engine has a massive torque spread compared to the TDI's small window of oppurtunity, and it's not peaky like a TDI either.

 

There are moves afoot to mandate diesel cats (like petrol cats from 1992 onwards) but these particulates are a technical problem. How do you stop the particulates clogging the cat?

 

With particulate filters. But they need something like 800 deg C to work, and diesel exhaust seldom exceeds 500 ish C. So PFs need post burn fuelling to get it up to temp, which is wasteful and why 60mpg diesels just don't exist in the REAL world.

You can "smell" PF'd diesels, nearly all current models have them. The exhaust smells less thick and choking.

 

As ever, cars and light comercial vehicles are not the problem. Buses, trains and HGVs are the engines that need cleaning up, but the government refuse to invest in these areas.

[dr_mat 0]

I am looking around, and the only petrol engines with turbos are performance cars, whereas almost any diesel has got at least a light pressure turbo, which in my opinion is to mask their woeful performance in order to fool the general public into buying them

 

There's plenty of petrol cars with low pressure turbos too. Saab have been doing it for years, as have Renault, Volvo and plenty of others. Even VW were shipping 150bhp versions of the 1.8T for years and years. Not really a "performance" version when the bog standard N/A engine is 125 bhp.

 

I really meant to say: the majority of cars being sold have turbos, whether they are petrol or diesel.

 

I don't think that the general public are being persuaded to buy diesels just because of the turbo. It's true that diesels don't perform well without one, but the reason people are buying diesel is for the fuel economy. Most of the people buying don't even know what a turbo is, it's just an integral part of the engine, just like a g-charger or a 16v head is. Us lot of petrol heads are the minority in the car buying public (and we don't even BUY new cars, we all drive 10 year old VWs!), and as such we can have our own opinions about the pros and cons of diesels and it makes NO DIFFERENCE at all to what gets sold day after day to Joe Average.

 

And thinking about this differently for a moment, isn't the 16v head or the G charger a method of masking poor engine performance in order to sell a car? Take away the G60 from a G60 and what've you got? A 100 bhp 1.8. Woo. Rice pudding in no danger there. Take away the extra 2 cylinders from a VR6 and what do you have? A ~1.9 petrol engine with maybe 120 bhp. Woo. Not. You only have to look at the sales figures for the 2.0 8v Corrado to see what I mean ..

[aclwalker 3]

And thinking about this differently for a moment, isn't the 16v head or the G charger a method of masking poor engine performance in order to sell a car? Take away the G60 from a G60 and what've you got? A 100 bhp 1.8. Woo. Rice pudding in no danger there. Take away the extra 2 cylinders from a VR6 and what do you have? A ~1.9 petrol engine with maybe 120 bhp. Woo. Not. You only have to look at the sales figures for the 2.0 8v Corrado to see what I mean ..

Yeah, I get where you're coming from, but do diesels not have all those innovations too (possibly with the exception of the super charger)?

 

I'm really comparing diesel with petrol and am finding that diesels can't compete unless they have a turbo. I'm comparing petrol with diesel, not petrol 8v with petrol 16v.

 

I know the general public don't know or care about this finer point, but when I get non-petrolhead (or non-dieselhead!) friends and colleagues rubbishing petrol cars and bragging about the performance of their new diesel etc, I find it amusing that they don't realise that it's turboed up to get that performance. And consequently they're probably not even getting the fuel economy they think they are, which is another thing they go on about. If they'd tried the turboed petrol version then they probably would not bother getting the diesel.

 

People also talk about how diesel has greater fuel economy, and this may be true litre for litre, but I think it needs to be seen in the context of the supply of that fuel. For example, people say how uranium is incredibly energy dense, but the amount of uranium around the world, in pure mass terms, is minuscule compared to the amount of coal. So is it not possible to argue that, compared to the SUPPLY of uranium, our use of it in generating electricity is inefficient because it won't last very long? Some people are talking about peak uranium!

 

Whereas if you simply compared uranium with coal, without considering the supply of each, you'd conclude that burning coal to produce electricity was incredibly inefficient. As an aside, huge amounts of energy are expended in mining uranium which is never factored in to its cost, but that's another matter.

 

I don't know the breakdown of a barrel of oil, but I suspect that the balance has been shifting towards diesel due to the heavier oils now being extracted and that's what's driving the push to diesel. This is probably adding to the 'argument' that petrol is inefficient next to diesel, but if you could convert 95% of a barrel to petrol and only get 5% of it as diesel then I'm sure we'd be getting it rammed down our throats how burning diesel in cars is inefficient and polluting and a bad thing to do, because industry and transport would need it for the torque it provides and anything would be said and done to prevent us from using it.

[Kevin Bacon 5]

And thinking about this differently for a moment, isn't the 16v head or the G charger a method of masking poor engine performance in order to sell a car? Take away the G60 from a G60 and what've you got? A 100 bhp 1.8. Woo. Rice pudding in no danger there. Take away the extra 2 cylinders from a VR6 and what do you have? A ~1.9 petrol engine with maybe 120 bhp. Woo. Not. You only have to look at the sales figures for the 2.0 8v Corrado to see what I mean ..

 

But the irony there Monsiuer Reynolds is the 16V is gutless compared to the lesser 8V...in the midrange at least :lol: :D

 

I know what you mean though, and you could argue that the reason the Civic Type R has incredibly short gearing is to "mask" the fact it has very little torque in relation to it's power :)

 

On diesel, if they can reduce the weight of the engine block and get it to rev like a petrol, then it stands a better chance of winning over petrol heads as a viable alternative to petrol. I don't actually care what fuel I burn though, it's just the characteristics of diesel engines I don't like, not the fuel itself.

 

As I keep prattling on, E85 is better than both and for all the right reasons.

[aclwalker 3]

On diesel, if they can reduce the weight of the engine block and get it to rev like a petrol, then it stands a better chance of winning over petrol heads as a viable alternative to petrol. I don't actually care what fuel I burn though, it's just the characteristics of diesel engines I don't like, not the fuel itself.

 

As I keep prattling on, E85 is better than both and for all the right reasons.

Diesel is a pretty nasty smelling fuel which makes a right mess when spilled, and is a hazard for motorcyclists in particular, because it doesn't evaporate off the road surface like petrol does. On the other hand it's not a fire hazard like petrol in that it doesn't have flammable fumes.

 

E85 is interesting, although I'm not up on its technical benefits, but it has the problem that it is resulting in competition for land between food and fuel.

 

Of course the real solution is to reduce world population to a 'sustainable' level (whatever that would be). Then energy, food and many other world problems would be solved. We should be working towards firstly stabilising population at 0% growth, then slowly working to reduce it in a controlled fashion, but back in the real world it will likely take war, famine, natural disaster or all, to reduce the population and solve our problems for us.

 

Of course for population, and hence economy, shrinkage we'd need to ditch the capitalist model, and probably most of the world's religions.

 

Pretty heavy I know, but it's raining now and my Corrado is still in lots of bits due to this crack pipe replacement!

[Toad 0]

I got bored after a bit so I'll just add random points,. E85 sadly is a bit like organic food, people like the idea of it, but we simply cannot produce enough to provide fuel for all cars. Using basic maths and some hefty assumptions, 3t/acre of OSR, say you make 50% of that into biofuel, so you have 1.5 tonnes of fuel per acre, ake away the fuel used to grow, process and deliver the fuel and you're looking at 1t per acre, I use 2500l of fuel per year so I need 2.5 acres of land to grow enough fuel for my car.

 

Brilliant, that leaves me loads of space at home, but, there's 100,000 people in the local town, suddenly I need 250,000 acres. and land to grow fuel for lorries to deliver my food, etc etc.

 

Secondly, most petrol cars don't come with turbots for fuel economy reasons. More air in the cylinder = more fuel required. I don't know the mileage figures for 1.8ts, but people wouldn't put up with that economy, when they could have a 1.9tdi that does 60mpg. The reason deisels have turbos isn't to get loads more air into the cylinder to burn more fuel. Deisel just burns, not explodes, and the power comes from the air in the cylinder being heated and expanding. More air in the cylinder = higher cylinder pressures without shoving more fuel in.

 

Beigey and I were discussing the finer points of deisel particulate filters recently as we followed a rep mobile in filter regen mode, I'd not seen it before and was very surprised to see the clouds of smoke pouring out of the tailpipe.