Up-coming Vaux/Opel/GM 3cyl 1 liter

[Kapt. Q]

http://media.gm.com/content/media/intl/en/opel/news.detail.html/content/Pages/news/intl/en/2013/opel/08-07-newall-aluminium-3-zylinder-turbo.html

Very interesting torque figures.

Cheers!

[Evilution]

Re: Up-coming Vaux/Opel/GM 3cyl 1 liter

Very similar to the Ford Eco-boost engine as fitted in the Ford FF1.

[Big Performance]

Re: Up-coming Vaux/Opel/GM 3cyl 1 liter

The ford version can get to 185bhp....

[Kapt. Q]

Re: Up-coming Vaux/Opel/GM 3cyl 1 liter

It makes you wonder why Smart took such a backward step with the 451 petrol engines.

Not sure about a chain driven balancer in the GM offering. Hope the switching water pump is reliable, lol.

Cheers!

[Evilution]

Re: Up-coming Vaux/Opel/GM 3cyl 1 liter

The ford version can get to 185bhp....

They've broken the 200bhp mark now. Ford's Dunton "skunk works" is 5 minutes from me and they often use the country lanes for testing. The FF1 has been passed a few times and a new Mondeo with the swirly body wrap went passed once, looks a bit like an Aston.

[Thrumbleux]

Re: Up-coming Vaux/Opel/GM 3cyl 1 liter

Very interesting torque figures.

Cheers!

110lbs.ft. Not that great when a NA is capable of circa 70lbs.ft per litre. Implies 0.6bar of boost to me.

Very similar to the Ford Eco-boost engine as fitted in the Ford FF1.

When I read the Vauxhall unit is markedly undersquare I'll know to what extent the Vauxhall unit is a copy of the Ford.

It makes you wonder why Smart took such a backward step with the 451 petrol engines.

Quite! Every new model of fortwo has had (or will have) a new petrol engine. Unheard of elsewhere.

Not sure about a chain driven balancer

Cheers!

Nothing to worry about - 3cyl 2-strokes have employed them for years, and plenty 4-strokes too. Banish the rocking couple and still no buzzy secondaries to deal with.

new Mondeo with the swirly body wrap went passed once, looks a bit like an Aston.

On Friday I met an Aston coming the other way. Followed by a Fiesta - with the 'Aston' grill. Hope the Aston was going quickly enough so as not to let the Ford catch up and its grill appear in his mirrors...

[Kapt. Q]

Re: Up-coming Vaux/Opel/GM 3cyl 1 liter

My issue about the balancer is that is not actually needed mechanically, hence the 450 & roadsters not having one, putting this in negates some of the advantages of using a 3 cylinder because it adds complexity, moving parts, reciprocating mass and friction to reduce 'vibration' that will not actually damage the engine. Despite the GM blurb in the article, it is not really so difficult to address this 'issue' in other ways as Smart already proved (and why silicone engine mounts have not caught on ).

The torque is interesting because it is very broad and flat in delivery as a result of the variable timing and direct injection. Whereas the 450/roadster engine is tuned for a peak delivery at around 3500rpm (hence the long individual runners on the intake manifold). What GM and Ford have done escapes the need to be so limited by cam and intake.

Direct injection in petrol has had some issues in the past but I imagine these have been resolved.

Cheers!

[Thrumbleux]

Re: Up-coming Vaux/Opel/GM 3cyl 1 liter

My issue about the balancer is that is not actually needed mechanically, hence the 450 & roadsters not having one, putting this in negates some of the advantages of using a 3 cylinder because it adds complexity, moving parts, reciprocating mass and friction to reduce 'vibration' that will not actually damage the engine. Despite the GM blurb in the article, it is not really so difficult to address this 'issue' in other ways as Smart already proved (and why silicone engine mounts have not caught on ).

Broadly agree with the above only mentioning that in the case of Ford and GM the individual cylinder size (and hence piston weight, stroke length, and bore spacing) is larger than with the Suprex - giving rise to fiercer vibes.
On a 2-stroke employing a balancer shaft the bore spacings are quite extreme and the vehicle into which it is fitted has a low targeted weight - hence the desirability of reducing vibration. They also run theirs in ball races - which have a fraction of the friction of shells.
On a 4-stroke though they do add friction and weight but the benefits (engine downsizing) must (just!) outweigh those demerits.

The torque is interesting because it is very broad and flat in delivery as a result of the variable timing and direct injection. Whereas the 450/roadster engine is tuned for a peak delivery at around 3500rpm (hence the long individual runners on the intake manifold). What GM and Ford have done escapes the need to be so limited by cam and intake.

The Ford unit is maredly undersquare, the intention being to create the most compact combustion chamber possible giving clean combustion and low heat loss. The restricted breathing inherent in this configuration is compensated by allowing the turbo to fill in the top-end torque (hence the need for a turbo effective over a wide rpm operating range leading to a unit turning at 250,000 rpm at full whack). Contrast that with most turbo applications where the turbo is maximised for mid-range torque and a flat top-end is the norm.

Direct injection in petrol has had some issues in the past but I imagine these have been resolved.

Cheers!

The only issue I have heard of is carbonising of the piston. Are there others?
DI seems to be catching on though. Due to effective charge stratification at low loads, ie a rich kernel of mixture at the plug points?