Enigmatic 3.2JTS

[Ascari32]

Busso too was an Aeronautical Engineer!. Jano - both technically brilliant and incredibly pragmatic. Turned his engine out for the 158/9 in under 12 months I believe. Busso's V6, every car manufacturer studied it and no current V6 would be as good without understanding what he achieved. Better than the Dino V6 in my opinion. But the old twin cam was no mean feat either. Probably two of the greatest engines in the World - still to this day. 

[Ascari32]

Found a badge for your car that was assembled in Pomigliano d'Arco by F.I.A.T SPA 

Let's be clear.  Pomigliano d'Arco was never a 'Fiat' plant pre-takeover.  It's the spiritual home of Alfa Romeo Avio and the place where the RA 1000 RC.41 engine was built (in the first factory), powering the Macchi C.202 in my avatar!.  Might not be Arese, it's not Milan, but it's Alfa heritage.

I don't have any issue having Fiat Powertrain Technologies product (the TBi) under my hood.

Serious admiration for the technical knowledge conveyed in this informative thread.  If only you were actually consulting to FCA...

Thanks, just relieving the boredom. Retirement isn't all it's cracked up to be.

OK, so now the 159 goes like she just lost 400 kilograms! However, she sounds like a German Panzer. Above 3000 rpm it really sounds great. Below, absolutely awful.

She always suffered from droning at 2500 rpm. So, with Autodelta Headers, the increased flow just exacerbated it. It didn't move, just became more obvious.

Cue - Supersprint Central section; no Resonator - droning now gone. But Alfa  back boxes struggling with the level and starting to break - up, become ragg -ed. But at least it confirmed the issue surrounding the drone was related, if not entirely due to the resonator. However, having a spare Alfa twin cat, I long had my suspicions about that too!

Cue - New rear boxes. Dear me! An explosion of noise, filthy, scrambled noise and God, the level! But at least it confirmed my suspicions about the Alfa Cat. It can heard producing spurious products across the "Reed", which is formed by the way Alfa have crushed the twin cat outlets into one.

I reasoned, at low revs, the gas velocity across the Reed is sufficiently low to generate sound, similar to the way a clarinet. does. But in this instance, the two pipes join tangentially and where they Siamese, the edge is badly burred. Of course the capillaries of the two cats make it worse as they linearize the flow before the reed.

Cue - Supersprint Catalytic Converter. I have about three more weeks to wait before delivery. However the two headers will co-join; via the Flexis, at the input to this new cat. So it should help improve scavenging which Colombo Bariani Camshafts create, and the Autodelta Headers assist.

The camshafts alone, create 23.5 deg. of PVO, and how many carburettor-ed or Port Fuel Injected engines does anyone know, that can idle rock - steady at 750 rpm with that amount of valve overlap?

With the S.S. Cat, I expect the exhaust gases to be a lot cleaner - acoustically going into the S.S. centre section. However, I suspect the level to the new rear boxes will increase further and instead of waking the dead in Moscow, they will hear me coming in Beijing!

Solution - I really don't have one at the moment. The car drives like it has just shed 400 kilograms and above 3000 rpm it is glorious. At 4000 rpm, she is going like a missile - my wife complains it hurts her neck. There is no pleasing some folk! So whatever I do, I don't want to lose that.

Once, if, when, I get this sorted, I will need a new pair of rear tyres. They were new, less than 3000 miles ago. But there isn't much of them left now!



P.S. - Once the S.S. Cat is fitted and I doubt my problems will end there, I am going to try this device from Jetex Exhaust Systems - U936330, inserted into the S.S. central section, just before the "Y" which feeds the two back boxes. But I don't hold out much hope! Could be just snake - oil!       
 

[sportiva]

wow! you can wear out tires/tyres in less than 3k Miles or 4.8k kilometers
and you haven't been arrested you are very lucky.

[Ascari32]

Quoting my own words from the previous post:-

"The camshafts alone, create 23.5 deg. of PVO, and how many carburettor-ed or Port Fuel Injected engines does anyone know, that can idle rock - steady at 750 rpm with that amount of valve overlap?"

I do so, as an indication of what Alfa did not realise they had. And Colombo Bariani will supply even more aggressive cams - specially manufactured - should I want them.

The point being, only cool, fresh air is ingested at tick over; or when "lifting", as the fuel is Directly Injected at ~ top dead centre on the compression stroke. So even with a massive overlap - even by competition standards, there is no risk of fuel detonation in the manifolds or backfiring through the inlet tracts and even less risk of a crank - case explosion.

Again, I attribute the VVT system to Ferrari. And had Alfa marketing men not being attempting to create a "White Elephant", someone would surely have realised the potential of this engine.

If Chrysler can simply modify the design; just a little - refine if you like, such that it will still be in production until 2026; and just consider for a moment the size of their market share, it surely warranted more consideration. And the Chrysler is up to four litre capacity!

The bore/stroke ratio of the 3.2 JTS is pretty much on the money and when my 159 failed, the only comment it illicit - ed was, "It just did not want to stop - there was no flat spot." This was at 7200 - 7300 rpm.

It may not be an Alfa Engine. But it is in every way, in the spirit of an Alfa Engines!     

[kaleuclint]

BTW -- what is that "Powered by Holden" badge stuck to, anyway??  An Elfin??

The last vehicle I saw carrying this message was the local version of the Bedford CF van.

[Ascari32]

wow! you can wear out tires/tyres in less than 3k Miles or 4.8k kilometers
and you haven't been arrested you are very lucky.

Not really been hitting high speed, more checking on acceleration. Seems P Zeros are quite hard when new, but once you get beyond new, they seem to dump rubber very quickly. Well that's my experience with them on my GTV. In fairness, I think I can coax another couple of thou if I am not too silly. But this damned exhaust problem is really grating. I really think I screwed up on the back boxes.

But I do like the idea of that badge and the van connection. Farina badges used to be on Austins; A40? if I remember correctly.

[sportiva]

I have P zero Nero's on my Alfa Romeo GTV6 and I hope to get 20 thousand K from them, maybe I wont because they wear very quickly or I'm just getting old and slow

kaleuclint when I goggled "powered by holden" the Bedford badge was what I had in mind but I didn't find one. 

And to keep on topic at least the GM designed partially built? Holden V6 engine is of a 60° angle. not many V6's are 60° simply because most V6 cars over the decades were run down V8 production lines so a 90° V6 was just cheaper and easier to do. Even the Ferrari influenced V6 in the new Giulia is a 90° configuration.
I understand that partially built Holden engines were shipped to Italy for final assembly for the 159.
And how does the "Twin phaser" differ from Holdens variable valve timing system.

[Ascari32]

From the various articles I have read, the Holden/Chrysler versions had a smaller advance retard angle, 35 deg. seems to ring a bell. Whereas the Alfa VVT system is a full 50 deg. And some variants of the Vauxhall and SAAB 2.8 only have VVT on the inlet camshaft. Something Alfa did with the Variator on the 156.

Authorities have said, 85% of the improvements made with quad cam systems can be achieved by just changing inlet camshafts. It is inlet valve timing that is more critical. It thus follows, similarly, fitting VVT to just inlet camshafts will have a similar beneficial effect.

Also, when one looks at the rotors, the Alfa timing plate is much more sophisticated, less crude. Well that is no surprise, because when researching the position sensors of the VVT system, it transpires that it is exactly the same as Bosch used when developing their "Hall effect" devices.

The signal detected by the sensor is very small and there is considerable noise surrounding it. To minimise noise, part of the VVT rotor - the collar, is alloy, in an effort to keep the actual rotor's noise footprint out of the signal. And because it is such a small signal, to help differentiate it from noise, as much metal is cut away from the sensor plate to isolate the signal, as much as possible from the rotating sensor plate superstructure - which is ferrous. Hence the slots!

The hall effect signal is pseudo - triangular shaped, with a fair bit of noise sitting on it naturally. So when processing it to a form which the ECU system can use, it is amplified, then filtered to remove this noise; then amplified again.

It then drives a very precise "Zero - Offset Schmitt Trigger". Because it is triangular wave, both the positive going leading edge and negative going trailing edge, of the signal, will cut the "Schmitt - Threshold" at exactly the same level. The net effect is to produce a square wave output waveform, which has both a very fast rise/fall time and is accurate wrt timing within the context of the timing of the ECU.

If the signal is low, then the Schmitt Trigger can ultimately fail to trigger or indeed simply trigger late and introduce a error which in the extreme can lead to a code failure for cam timing; rear bank exhaust sensor as a case in point. This also has a bearing on the front bank manifold cat and cylinder head overheating issues - but that is another story.

As pointed out earlier, unless the sensor is correctly fitted, the amplitude of the triangular wave quickly diminishes. And Bosch state, the field generated by the rotor plate should pass the sensor face at a right angle +/- 0.5 deg.


So the rear bank sensor is incorrectly fitted to the 3.2 JTS. This probably came about because the panels were cast when there was no VVT fitted to the exhaust camshaft.

However, with regard to Ferrari's involvement, it is my belief that the software control for the system and hence the ECU program is likely to be theirs. It is too good for Alfa to have come up with it - in my opinion.

   

[kaleuclint]

And to keep on topic at least the GM designed partially built? Holden V6 engine is of a 60° angle. not many V6's are 60° simply because most V6 cars over the decades were run down V8 production lines so a 90° V6 was just cheaper and easier to do. Even the Ferrari influenced V6 in the new Giulia is a 90° configuration.

Interestingly the "Ferrari-built" (using a U.S. cast block) Maserati Ghibli V6 is 60 degrees. 

[Ascari32]

https://r.search.yahoo.com/_ylt=AwrJQ5ylzCdfV2UAaDEM34lQ;_ylu=X3oDMTByaW11dnNvBGNvbG8DaXIyBHBvcwMxBHZ0aWQDBHNlYwNzcg--/RV=2/RE=1596472614/RO=10/RU=https%3a%2f%2fwww.cycleworld.com%2f2013%2f08%2f01%2ftechnical-analysis-90-degree-v-four-engine-motogp-racing-technology%2f/RK=2/RS=3o75W9dXdmr8qpomHXr7F5mvFng-

Here's that name "Jano" again!!!!!!!!!!!!!!!!!!!!!

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Ferrari increased the angle of his V 12 from sixty, by a few degrees to allow better inlet tract flow. Ninety degree V6's have a lower centre of gravity and allows much better inlet manifold design.

[Colin Edwards]

I guess the 3.2JTS is like anything else..........good enough for the present requirement and to be superseded as soon as the next iteration is released.  If continual development wasn't a requirement, we would all be still driving cars resembling the Model T Ford.
Like all engines, the 3.2JTS was just a stop gap design while the next engine is being developed.  The 12V Busso was a fair engine for its day, however very soon replaced by the 24V model.  That again was ok until superseded by the improved 3.2JTS.  None of these engines, in retrospect, was perfect.  They all had their design limitations.

No doubt the 3.2JTS had its limitations.  If it had none, it would still be manufactured.  Methinks Alfa Romeo / Fiat very soon acknowledged its shortcomings (as would be the role of engineers and accountants) and developed the Multiair system.  Certainly a more elegant and efficient way of controlling valve events.  The Multiair probably addresses most of the valve event and related hydraulic control issues identified in the 3.2JTS.  Makes sense to incorporate the recent advances in high speed mechatronics and general processing grunt.

With regard to the use of Hall Effect devices and signal processing, back in the early 1990's, a local lift manufacturer (who I used to work for!) used Hall Effect devices for velocity and distance measurement.  Tested and reliable well beyond 75,000 pulses per minute, the locally developed electronics and supporting software had no issues operating in a very hostile environment.  The application was unique however the technology was not.  High speed signal conditioning has been around for a very long time and high noise immunity Schmitt trigger technology for nearly as long.  Methinks any run of the mill electronic engineer and software engineer at Alfa would have had the expertise to develop the required systems. 
Then again, if an elegant solution exists within the group / company, why reinvent the wheel. 

 

[Ascari32]

I can't agree with your analysis, it is a little too sympathetic towards Alfa Romeo and neglects the fact that they continually sit back and allow the field to get ahead of them. And the Multi - Air is no substitute for a 3.2 V6.

That Chrysler are keeping this engine; with some re - engineering work, in production until 2026 demonstrates Alfa failed to grasp the point about it's potential when it hurriedly dropped it, and the 159/Brera. Particularly after all the fanfare!

The GT only came to market because there was no replacement car available after the success of the 156 - again another car they dined out on, well beyond it's sell by date. The GTA stretched Busso's masterpiece to 3.2 litres in an attempt to keep the market interested. An illustrious title given to a dressed - up, "Buy One, Get One Free" front wheel drive car which should have been replaced long before it finally ceased production.

The company makes no mention of the fact that Busso' masterpiece was seen as a history, Busso having left the company two years, before Alfa thought to introduce it. Why? Because the new crop of management, and engineers simply carried on as before, sitting on their hands, not really having any idea how to move the Marque forward.

When the Busso adopted four valves per cylinder, it was for technical reasons surrounding emissions. They would just as soon have not bothered. But legislation left them no option. Yet again, they didn't think they needed too.

It was not for technical reasons the 3.2 JTS superseded the Busso, it was financial - pure and simple. Fiat were in financial difficulties, they wanted to close Arese and they were negotiating to climb into bed with another lame duck.

So the 3.2 was a Wedding Present. Albeit, a bit tacky! So they felt they needed to dress it up a bit. And failed miserably. The Platform of the 159 is superb, cost 2 billion in development and it too went the way of the Dodo.

Not what one could call commercial sense for a Prestige Marque, to leave itself without a flagship model for so long.

The history of the Holden V6 is quite convoluted.

The design concept owes much to Ford's Duratec V6 with its primary engineering input coming from Porsche. The engine subsequently finding its way into Jaguars amongst others.

When the development team was broken up, fortuitously it found itself being substantially reformed under the Chrysler Banner. There are still elements of the Holden/Chrysler V6 covered by patents held by Porsche. So it is not without Pedigree!

The 3.2 JTS certainly has it's limitations. But none that Alfa Romeo Identified. However, they certainly added a few of their own! And still we are without a true Alfa Engine. The 2.9 belongs to Ferrari. After a litany of engineering disasters, spanning decades, it is inconceivable Alfa could have pulled this gem out of the hat like a rabbit.

With regard to Hall Effect, it was discovered by Edwin Hall in 1879 but little was done with it for many decades. For me, it is not new technology, but certainly not old. Stability was never very good in the years Valve Technology held sway, the era I hail from. With the advent of semiconductor technology; yet still discrete components, things got a lot better. And microprocessors now enable such technology to be employed in everyday devices.

Impedance Modulation was well understood as a method of increasing Broadcast efficiency, beyond what was thought to be theoretically possible. However, the man who invented it was long dead before component tolerances in manufacture made it possible to produce very efficient transmitters in the 1980's. And companies such as Bosch, can explore and develop technologies, the study of which lie in the vaults of many University Research Libraries.               

[sportiva]

The developement of the 159 has nothing to do with Chrysler and all to do with a General Motors/F.I.A.T. merger
Chrysler were in bed with Mecedes Benz when the 159 was released,

[Ascari32]

I stand corrected - apologies for that. Senior moment kicking in!

However, I wondered why a block with such obvious strengths found its way into this engine? Even one Company Director, who gets considerably more from this engine phoned me to acknowledge its obvious virtues, having only just properly inspected it for the first time. Yet it is roundly condemned here in the UK, but no one seems able to give factual reasons for such an overtly negative view. 

[Colin Edwards]

From a personal perspective, I had no problem with the 3.2JTS in my 159.  Apart from needing to replace spark plugs not long after purchase as the car still had the originals after 70,000klms use, nothing of note to mention.  Then new plugs every 30,000klm.   Also always replaced engine oil and filter every 7500klm.  Always fed it 98RON.