Author Topic: Enigmatic 3.2JTS  (Read 3953 times)

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Ascari32

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Re: Enigmatic 3.2JTS
« Reply #30 on: August 05, 2020, 05:56:06 PM »
Sounds like a recipe for longevity. I doubt that too many in UK go to that length - regardless of Marque!

The Brera engine I rebuilt was run dry at about 40 - ish k. Many car owners do not change their oil and filter often enough, let alone have them properly maintained.

As a lot of cars are bought on Personal Finance Plans, I suspect their servicing schedules run along the lines dictated by the dealerships they bought them from, never thinking that the intervals are perhaps not best suited to every car. Meaning - some owners are thoughtful about the way they use their cars, others may not be.

So, buying on the secondhand market can be a bit of a minefield.     

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #31 on: August 25, 2020, 07:22:42 PM »
The old AlfaSud plant were the last 159 was built is very close if not next door to the aviation division.
 I acknowledge and understand the history of the two plants and the radial engines alfa romeo built under the leader ship of Ugo Gobbarto were splendid examples of engineering.

The travails of this Enigmatic car continue! To be fair, it is not of Alfa's making - damn. It has more to do with the way I chose to modify my car. The manifold cats have gone. They are the metal type and clearly can withstand much higher temperatures. Although I knew the twin cats below the car are Ceramic and thus lower temperature, I felt as they are some distance away from the engine, they would probably cope ok. It was the output of the twin cats that appeared to be the problem as they  form a "Clarinet Reed" for the gases exhausting into the central section where the resonator is. After my modifications, the higher power level was causing extreme droning @ ~ 2500 rpm.

I fitted a Supersprint central section which has no resonator and sure enough, the drone disappeared. But this resulted in a cacophony of noise emanating from the rear boxes. Cue new rear boxes - a lot worse, although both the sound and acceleration from 3000 rpm is brilliant. But impossible to live with at below.

My worst fears seemed to be confirmed - a new cat would be needed. And Supersprints is not cheap. So having bitten the bullet, contacted Supersprint Technical Department. By this time, the Cat had been ordered, but I had the daunting prospect of having to buy yet another pair of rear boxes as the new ones seemed incapable of handling the power. I wanted Supersprints assurance theirs, which would complete my system once the cat is installed, would handle the extra power. I quoted a figure of 350hp as a target figure. I even picked up a brand new Alfa Nearside Box cheaply, fearing I would end up going back to theirs. It confused me, the Alfa boxes handle the lower revs well, but break up at higher revs, the new ones handle higher revs, but break up at lower ones.

I needed Help.

That's where S.S. tech dept. came in. I laid it out as baldly as I could and within the space of the weekend I had a comprehensive reply.

"It's not your rear silencers that are your problem, it's your cat". Brilliant, so at least I had a second opinion supporting my view about the Alfa Twin Cat".

But not for the reason I believed. Quote:- "I would be very surprised if there are any cells left in them". They are 500 CPI (Cells per inch) and very restrictive.

So to shorten a long story, having a spare twin cat in the garage - which I was intending to take to the dump - I got a garden chair to sit on, a 10mm. piece of stainless pipe, an eight pound club hammer and drove the pipe through the cat. Initially it was very reluctant but eventually smashed my way through. A quick check below and sure enough, there were pieces of the Ceramic Cat on the garage floor.

I picked up, what clearly had been part of the outer matrix, which was very hard. The initial strength must have been this outer screen/matrix. However, along with it on the floor was part of the inner honeycombe. Inspecting that revealed it was almost of a dust consistency - extremely crumbly. One could rub a small lump between two fingers and it quickly fell to dust/coarse powder.

So, full marks to the Supersprint tech guy for pointing me in this direction. I don't think the "Reed" helps, but if my twin cat has collapsed cells, it certainly would contribute to my problem.

Funnily enough, after a quick blast to get out into mainstream traffic flow, from a junction yesterday, the exhaust system appears to have got a little less "Rackety". It's not the way it should be. But it seems a bit quieter. And although my doubts about my new rear boxes remain, the throttle response is such that, blipping the throttle a little on down shifts brings an exhaust note that reminds me of my old twin cam Berlina and her Dellorto carburettors.

Funny - the tricks the mind can play on perceptions!!!!!!!     

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #32 on: August 25, 2020, 08:42:59 PM »
The old AlfaSud plant were the last 159 was built is very close if not next door to the aviation division.
 I acknowledge and understand the history of the two plants and the radial engines alfa romeo built under the leader ship of Ugo Gobbarto were splendid examples of engineering.

The travails of this Enigmatic car continue! To be fair, it is not of Alfa's making - damn. It has more to do with the way I chose to modify my car. The manifold cats have gone. They are the metal type and clearly can withstand much higher temperatures. Although I knew the twin cats below the car are Ceramic and thus lower temperature, I felt as they are some distance away from the engine, they would probably cope ok. It was the output of the twin cats that appeared to be the problem as they  form a "Clarinet Reed" for the gases exhausting into the central section where the resonator is. After my modifications, the higher power level was causing extreme droning @ ~ 2500 rpm.

I fitted a Supersprint central section which has no resonator and sure enough, the drone disappeared. But this resulted in a cacophony of noise emanating from the rear boxes. Cue new rear boxes - a lot worse, although both the sound and acceleration from 3000 rpm is brilliant. But impossible to live with at below.

My worst fears seemed to be confirmed - a new cat would be needed. And Supersprints is not cheap. So having bitten the bullet, I contacted Supersprint Technical Department. By this time, the Cat had been ordered, but I had the daunting prospect of having to buy yet another pair of rear boxes as the new ones seemed incapable of handling the power. I wanted Supersprints assurance theirs, which would complete my system once the cat is installed, would handle the extra power. I quoted a figure of 350hp as a target figure. I even picked up a brand new Alfa Nearside Box cheaply, fearing I would end up going back to theirs. It confused me, the Alfa boxes handle the lower revs well, but break up at higher revs, the new ones handle higher revs, but break up at lower ones.

I needed Help.

That's where S.S. tech dept. came in. I laid it out as baldly as I could and within the space of the weekend I had a comprehensive reply.

"It's not your rear silencers that are your problem, it's your cat". Brilliant, so at least I had a second opinion supporting my view about the Alfa Twin Cat".

But not for the reason I believed. Quote:- "I would be very surprised if there are any cells left in them". They are 500 CPI (Cells per inch) and very restrictive.

So to shorten a long story, having a spare twin cat in the garage - which I was intending to take to the dump - I got a garden chair to sit on, a 10mm. piece of stainless pipe, an eight pound club hammer and drove the pipe through the cat. Initially it was very reluctant but eventually smashed my way through. A quick check below and sure enough, there were pieces of the Ceramic Cat on the garage floor.

I picked up, what clearly had been part of the outer matrix, which was very hard. The initial strength must have been this outer screen/matrix. However, along with it on the floor was part of the inner honeycombe. Inspecting that revealed it was almost of a dust consistency - extremely crumbly. One could rub a small lump between two fingers and it quickly fell to dust/coarse powder.

So, full marks to the Supersprint tech guy for pointing me in this direction. I don't think the "Reed" helps, but if my twin cat has collapsed cells, it certainly would contribute to my problem.

Funnily enough, after a quick blast to get out into mainstream traffic flow, from a junction yesterday, the exhaust system appears to have got a little less "Rackety". It's not the way it should be. But it seems a bit quieter. And although my doubts about my new rear boxes remain, the throttle response is such that, blipping the throttle a little on down shifts brings an exhaust note that reminds me of my old twin cam Berlina and her Dellorto carburettors.

Funny - the tricks the mind can play on perceptions!!!!!!!     

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #33 on: August 30, 2020, 06:20:05 PM »
For me, "Enigmatic"remains the term most applicable to this car, but more specifically the engine. It is difficult, without access to full workshop facilities to move anything along quickly - automotively - a local exhaust fabricator is fully booked up until November and I await my Sports Cat with baited breath.

In the mean time, I have been ploughing through E.U. Research Documents on Emissions, Manifolds, Catalytic Converters, Diffusers, Resonators and Silencers/mufflers.

One document is 317 pages long. It covers these areas scientifically but seems to be directed at guidance for car manufacturers in a manner, which allows scope to develop their own unique way of resolving emissions issues. Compliance being the critical point. How it is achieved is up to individual car makers.

Catalysts however, remain mandatory!

But there are many ways of skinning a cat! And it appears to me, it gets to a point when ultimately car manufacturers apply economics to solutions in a manner which cannot be sustained from one generation of cars to the next. I wonder if the drive towards electric would have been so fast, had not motor manufacturers applied more of the known science to getting emissions under control, than they have hitherto.

Which brings me back to the engine which I term "Enigmatic". So little is given away by manufacturers, with regard to their motives for adopting x,y or z approach to problems which are common to virtually all cars. OK, specific perhaps in the sense they are diesel or petrol driven, but common wrt either type.

And so I return to the issue of valve timing in respect of the 3.2 JTS. If anyone has further expert knowledge or insight into this issue, I would appreciate their views. It certainly would be a lot easier than having to pull together all the specific research contained in 317 pages into one concise document. Trying to determine the interrelationship between such complex areas is hard work. However, I think I have; courtesy of such documents, stumbled upon another reason for Alfa's choice of valve timing, in particular the exhaust valve timing.

Not only would it appear to be their method of generating "Internal EGR", it may also be intended to reduce "Reverse Flow" through the Catalytic Converter Element. By closing the exhaust valves at such an angle, it probably reduces any depression pulling gases back into the cylinders, thus slowing gases through the cat or indeed causing reverse flow. I am still working my way through this one.

However, one thing I am absolutely certain of is the second feature of closing the exhaust before the inlet opens. There is little point in fitting manifold cats in an attempt to maintain "Light - off", which enables Catalization, if valve timing allows cross-flow between inlet to exhaust - PVO - which would in effect cool the Catalytic Converter down!

Somehow, it all seems to have got lost in the mix for Alfa. It is Paradoxical for a company whose History is founded upon a "Racing Heritage" to apply such contradictory principles to cars such as the Brera and 159 and claim they continue this into the modern era.

As flawed as they are, the 147/156 GTA's are more in keeping with that ethos than these two models. Even the base model 147/156 can be tweaked by enthusiasts, in much the same manner as Berties, Berlina's and Spiders were. And it wouldn't cost a Kings Ransom.

It's a shame, given the 159 and Brera are both fine cars. If only Alfa had not gone so far in strangling the life out of the engines for the sake of fickle legislation, which so often changes due to "Woolly Headed Bureaucrats". The 3.2 JTS would comfortably made 280 BHP and could still have met emissions regulations had they really wanted to maintain their sporting image. I calculated, the Q4 would need to be 286 BHP to match the 156 GTA. Front wheel drive versions would have bested it!

Wasted opportunities. And now we all need deeper pockets to afford Alfa's.       
« Last Edit: August 30, 2020, 06:24:05 PM by Ascari32 »

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #34 on: October 10, 2020, 09:42:10 PM »
The Supersprint catalytic Converter has now been fitted to my 159 for about two - ish weeks. The Alfa boxes cope very well and it generally sounds very sweet, with no popping or farting on overrun. Just a good solid "Blat". But it still did not feel entirely right.

At the same time as the cat going on, a failed rheostat was found and a replacement ordered. I thought I was faced with a very big bill for the climate control system; but no, the guys picked it up very quickly and temporarily the A/C is working.

Although not quite feeling right, I believe when the rheostat is replaced, i will refit my new boxes again. I think that is only fair, before I consign them to the scrap heap/ebay. Prior to the S.S. cat going on, I was experimenting with different fuel grades, provoking management codes at will when swapping from RON 95 to 97. However, I had not cleared the codes when the cat was fitted.

Subsequent to this, I disconnected the MAF, wondering if the slight lack may be due to the MAF, but no change. So I went and saw the guys and asked if they could just give the history file a once over and reset the alarms for me. There was a fairly substantial log to be cleared, all relating to Lambdas and MAF with a couple of cylinder misfires in the mix.

Since the log has been reset however, that slight niggle about performance has evaporated. The engine is running beautifully. Silky smooth at low rpm and what is particularly noticeable is how smooth it is when pulling away and changing up. First and second have always been "Notchy" and not getting it right, the the revs would die off very quickly. Getting my timing right between first and second was crucial. But, because there is now so little drag on the engine - the engine gently dies - off the revs; as I dip the clutch, move from first to second and the re - engage. It really seems like a different car. Progressively it gets better 2nd to 3rd, 3rd to 4th. And fifth and sixth have never been a problem.

Acceleration is strong, with no flat spots, revs rising very quickly, the car belying its weight. Exhaust, very throaty at low revs but I do miss the sound it makes with my new boxes over 3000 rpm. Not bad though and the Alfa boxes coping well. Noise levels are very acceptable - nothing like the original but acceptable. Tick - over solid but meaty. I cannot see that when the new boxes are refitted, it will be any quieter. So that mat be the sticking point. But it is worth a try.

I shall have the front drivers side wheel bearing changed at the same time as the rheostat is done as that is the only untoward noise coming from the car. All in all, I love it. Next stop - heart in mouth - Dynamometer. But I will wait a couple of weeks, just building up the courage. That aside, what a fabulous car the 3.2JTS Q4 is - now!!     
« Last Edit: October 10, 2020, 09:45:55 PM by Ascari32 »

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #35 on: October 10, 2020, 09:50:27 PM »
The Supersprint catalytic Converter has now been fitted to my 159 for about two - ish weeks. The Alfa boxes cope very well and it generally sounds very sweet, with no popping or farting on overrun. Just a good solid "Blat". But it still did not feel entirely right.

At the same time as the cat going on, a failed rheostat was found and a replacement ordered. I thought I was faced with a very big bill for the climate control system; but no, the guys picked it up very quickly and temporarily the A/C is working.

Although not quite feeling right, I believe when the rheostat is replaced, i will refit my new boxes again. I think that is only fair, before I consign them to the scrap heap/ebay. Prior to the S.S. cat going on, I was experimenting with different fuel grades, provoking management codes at will when swapping from RON 95 to 97. However, I had not cleared the codes when the cat was fitted.

Subsequent to this, I disconnected the MAF, wondering if the slight lack may be due to the MAF, but no change. So I went and saw the guys and asked if they could just give the history file a once over and reset the alarms for me. There was a fairly substantial log to be cleared, all relating to Lambdas and MAF with a couple of cylinder misfires in the mix.

Since the log has been reset however, that slight niggle about performance has evaporated. The engine is running beautifully. Silky smooth at low rpm and what is particularly noticeable is how smooth it is when pulling away and changing up. First and second have always been "Notchy" and not getting it right, the the revs would die off very quickly. Getting my timing right between first and second was crucial. But, because there is now so little drag on the engine - the engine gently dies - off the revs; as I dip the clutch, move from first to second and the re - engage. It really seems like a different car. Progressively it gets better 2nd to 3rd, 3rd to 4th. And fifth and sixth have never been a problem.

Acceleration is strong, with no flat spots, revs rising very quickly, the car belying its weight. Exhaust, very throaty at low revs but I do miss the sound it makes with my new boxes over 3000 rpm. Not bad though and the Alfa boxes coping well. Noise levels are very acceptable - nothing like the original but acceptable. Tick - over solid but meaty. I cannot see that when the new boxes are refitted, it will be any quieter. So that mat be the sticking point. But it is worth a try.

I shall have the front drivers side wheel bearing changed at the same time as the rheostat is done as that is the only untoward noise coming from the car. All in all, I love it. Next stop - heart in mouth - Dynamometer. But I will wait a couple of weeks, just building up the courage. That aside, what a fabulous car the 3.2JTS Q4 is - now!!

P.s. The feeling of having lost a little at the bottom end has now gone, with good solid torque coming in, low down Always better than standard, it just seemed in the process of trying to resolve my exhaust/cat problems, a little was lost in the mix. Now, back to what it was - absolutely fine. Hope that feeling wasn't down to my new boxes. However, I will find that out when I refit them!!! 

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #36 on: November 07, 2020, 09:52:50 PM »
The Saga goes on - and on - and on!

Ascaris now History although they have been useful in trying to resolve the exhaust issues, which I believed were at an end.

The Standard 3.2 JTS has valve timing such that the engine is 11.5deg. into its induction stroke before the inlet valve opens, the exhaust valve having closed 3.5deg. earlier. Thus there is no crossflow - air passing from inlet to exhaust. So the velocity of air in the inlet tract is interrupted, if not completely halted.

As a result, it is difficult to see how good volumetric efficiency can be achieved. Also, this means the ECU has a less time to calculate the Air flow upon which it can meter the fuel injection. So; by my reasoning, Alfa needed to fit a MAF with a very fast rise-time; dr/df transfer characteristic - a steep slope, to enable the ECU to read Peak Airflow very quickly.

Unfortunately, when fitting the Colombo Bariani camshafts, which have a 23.5deg. valve overlap, the increased air flow, - crossflow element+cylinder fill results in the ECU setting AFR which is too rich. The obvious consequence of this is the powerful/meaty exhaust sound, even though the engine is at 750 rpm - solid: and rich operating conditions overall.

So logic suggested, a MAF with a different Transfer Characteristic is needed. I tried a new 916 GTV 2.0 version - (2) on the attached data sheet - and there was a good improvement at the lower end with a more subdued tickover. But it's range is too low and it topped - out at 4500 rpm, which tied up with Bosch's data sheet.

I then tried the new MAF from my 3.0 GTV - (3) on the attached data sheet - which clearly has a higher flow rate and things really did improve dramatically.  So much so, that I was able to "Trim" the output signal with resistance values the original 3.2 JTS MAF would not tolerate.

This was where the Ascaris became invaluable. Small changes in the "R" - values were immediately reflected in a change in the character of the exhaust sound emanating from the Ascaris. Indeed, the character of the exhaust became that much more harmonious, acceleration seemed sharper to the extent that it seemed like major changes had been made and not just changes to (R) values. I eventually settled for 600 ohms, nearly three times that of the test values used when trying to understand the problem with the original JTS MAF.

At this point, I decided to stop as I had already booked the car in for the Alfa Boxes to be refitted. During this period, I was searching for a MAF which would give me a less acute transfer characteristic and the only one I could find, which was a HFM 5 was the 911 Porsche 2.8L. My logic being such that, a turbo car would require a lower/less acute transfer characteristic. But needless to say, that is expensive. An alternative; I thought, could well be (5) on the attached data sheet, but that is very difficult to find - I have seen it, but at Mega Bucks.

Happily, I found version (4) on the data sheet which is used on some Volvo models. It's transfer characteristic follows a similar profile as (3), but with a higher airflow limit. I am hopeful that I can also trim the dr/df transfer characteristic to give an optimum AFR characteristic.

Although not as precise as the Bosch method - which is why the covers on these sensors are sealed with a gasket enabling the makers to calibrate the response to any car makers requirements - it would require test facilities which are beyond me. But, it isn't entirely crude and should enable me to adjust fuel metering to a greater degree of accuracy than with the JTS's standard MAF. Indeed, were I to fit a vernier resistive network and quality AFR gauge, it would be possible to trim fuel continuously on long journeys.

Alas, whilst standing in the workshop as Adam drove the 159 into the bay, with the Ascaris, it finally sounded absolutely glorious. Nothing like it sounded from the driver's seat. So I suppose it must be down to acoustic coupling. Either way, they will go on eBay or to the dump. The Alfa Boxes are back on now, but they have benefited from the ability to set the current loop of the MAF when the Ascaris were fitted. 

The Bosch 0280218008 MAF should be here in a week or two and the exercise of trimming the loop again will be done with the Alfa boxes insitu - I hope they are as responsive enough to find the sweet spot as it was with the Ascaris.

Torque seems a little stronger below 1500 rpm and beyond she just comes on strongly, but with less audible drama which I got with the Ascaris. If only I could have made them work! Above 3000 rpm, they are in a league of their own!     

torquemeister

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Re: Enigmatic 3.2JTS
« Reply #37 on: November 14, 2020, 06:43:58 PM »
Found a badge ;) for your car that was assembled in Pomigliano d'Arco by F.I.A.T SPA  :)
Lets be clear - Alfa took the small bore GM block and developed their own variable multivalve heads for it. A former colleague was a design engineer at GM Elizabeth at the time and he said when the first units were shipped back to GM Oz for review the engineers complained that Alfa had done what they had not been able. SIDI was a result or Alfas work.
People get misty eyed over the Busso but it could not meet EU emissions compliance so naturally Alfa had to cast about within GM and come up with a solution.
Comments re 600HP out of the engine? Seriously? Its well known that the AutoDelta SC kit boosts HP but at the expense of the transmission. So there is NO WAY that you can put down 600HP in that 939 Series configuration without major rework of the entire driveline.
Current Fleet:
2010 Brera V6 AWD Auto - Singapore
2008 Brera V6 AWD Auto - Tasmania
Previously:
1978 Alfetta GTV 2.0L - Adelaide

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #38 on: November 14, 2020, 10:39:41 PM »
I would like to know what exactly what it was Alfa did that GM could not? From my studies of the both Brera and 159 engines, Vauxhall and SAAB, there is no difference in the architecture of the Block.

Whereas Alfa of old would have cast swage/baffle plates into the sump and certainly not returned oil from the heads in miniscule amounts, down cavernous channels, such that it appears in the sump at a level, and exactly in - line with the rotating Crankshaft Journals, to be immediately whipped into windage.

Neither would they have failed to see, the windage plate(s) does not extend along the full length of the sump, exacerbating "Slosh" - for want of a better term. The second plate was a latter addition by GM I am informed. Nor would the fact that the oil pick - up in the sump sits too high above the sump floor and is readily exposed if oil level are not scrupulously maintained, when lateral forces shift the oil in the un-swaged/baffled sump, have gone un - noticed.

Or that the sump was too small for the amount of oil in circulation to be healthy - deigned around a 4 litre capacity with 1.8 litres in circulation. This is a figure before the addition of VVT's on all four camshafts.

I had no interest in GM engines prior to my 159. However, these failing firmly belong to GM. So much so, that the latest incarnation of this engine; which is planned to be in production until 2026, incorporates modifications to rectify these issues.

My studies began with a wrecked 40,000-ish miler Brera engine [oil starvation] and only developed into a full-scale project when my 159 engine failed - on a parabola, with a full sump of new oil and a new oil filter. So a detailed exercise was undertaken - I was not simply going to replace what Alfa had served up to their customers. It is not being unkind to say, amongst UK Alfa enthusiasts this engine is very poorly regarded - being polite.

I can understand any sense of pride having a GM engine in and Alfa would generate for you guys. I hold the block of this engine in very high regard. It is incredibly strong and I have been reliably informed it is good for 600 BHP, but I'm not aware that it is in an Alfa 159 or a Brera. It is alleged the limiting factor with Autodelta is fuel delivery.

Having been a continuous owner of Alfa's, to the exclusion of all other marques for almost forty years, I can only think their engineering department has become so depleted that they didn't even bother about looking at the issues I have alluded to above, simply choosing to focus on reworking the Heads.

But it is generally accepted in engineering circle, it is not a good idea to have a single oil pump provide for all the needs of such a complex engine. Or, have the most fundamentally important component - lower timing chain tensioner - at the very end of the oil supply system. Or to deplete it's oil supply even further by having "Leaky VVT Solenoids". Or, fail to read the data, Bosch go to great length to supply and ensure, all four camshaft positional sensors are correctly aligned, choosing to use a boss on the front cover simply because it saved them from re-casting it in the correct orientation. The front bank inlet and exhaust sensors, plus the inlet sensor of the rear bank are perfectly aligned. The rear bank exhaust camshaft sensor is not. Bosch quote +/- 0.5deg. off - axis limit. So it is hardly surprising it is always, to my knowledge, the rear exhaust cam which flags a code for camshaft timing error!

Furthermore, there are four serious restrictions, cast within the block, which are difficult to overcome, without supplementary oil feeds. I believe, the latest incarnation overcomes these, but unless I get my mittens on one, cannot swear to it. The JTS system is a brilliant concept but Alfa failed to grasp the niceties of making it work - properly. There was pressure on them to introduce a replacement for the Busso. As a result they seemed to have incorporated a lot of the research work being done in an E.U. funded study. The study was intended to give guidance on emissions and although many aspects were investigated, it was intended for guidance. All manner of techniques were investigated, not all of them intended to be used in the same package, I believe. But Alfa chose to use a lot more than deemed necessary. They achieved a top rating for the engine when it was released. But very few have stood the test of time. In fact they are becoming an incredibly rare sight.

The Busso remains a brilliant benchmark engine. I have a low mileage 3.0 litre GTV. But the 3.2 JTS is, when all the encumbrances are removed and it is allowed to work properly, is more than a match for it.

However, the Busso, will remain the last truly great Alfa Romeo engine, Designed and Built in - house by one of the greatest Automotive Engineers that lived. The longevity of its production run alone speaks volumes and I do not know of a single V6 that does not owe it's design to some aspect of what Busso achieved.

The 3.2 JTS engine had what must have been the shortest of production runs in the automotive industry, let alone with Alfa. I doubt there will be many to be found in a few short years, such is its reputation. Whereas, the Busso will go on and on, as long as there are Alfa Romeo enthusiasts in the world. And I predict it will command high prices. One can pick up a 3.2 JTS for 200.

Despite this, I have an extremely high regard for this engine, once its issues have been addressed.                   
« Last Edit: November 14, 2020, 11:33:57 PM by Ascari32 »

Ascari32

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Re: Enigmatic 3.2JTS
« Reply #39 on: November 15, 2020, 03:16:08 AM »
Found a badge ;) for your car that was assembled in Pomigliano d'Arco by F.I.A.T SPA  :)
Lets be clear - Alfa took the small bore GM block and developed their own variable multivalve heads for it. A former colleague was a design engineer at GM Elizabeth at the time and he said when the first units were shipped back to GM Oz for review the engineers complained that Alfa had done what they had not been able. SIDI was a result or Alfas work.
People get misty eyed over the Busso but it could not meet EU emissions compliance so naturally Alfa had to cast about within GM and come up with a solution.
Comments re 600HP out of the engine? Seriously? Its well known that the AutoDelta SC kit boosts HP but at the expense of the transmission. So there is NO WAY that you can put down 600HP in that 939 Series configuration without major rework of the entire driveline.



Let's also be clear about the pedigree of this engine. The team that developed the V6 engine for Ford/Jaguar had been broken up when the project ended. Porsche were heavily involved with it, to the extent they still hold patents on elements of its design. Ex - members of the team became involved with the new engine GM wanted develop, in which Holden also played a part.

It is a testament to it's design that Alfa chose to use it, but to be honest they were over a barrel given their engine plant was being closed. So in essence, to claim it as their own, and given the reputation the Busso had, it had to be radically different. However, the block is a modular design, in this instance specified as 3.2 litre. But it is not true they developed/modified the block further. The heads yes, with all components already available on the market - V.V.T's included. So apart from recasting the heads, little design work went into the Alfa 3.2 JTS.

To add to the woes the lower timing chain tensioner suffered was the spray jets which bleed oil from the main gallery and further reduce the supply to the tensioner. Not only that, they are low pressure and are known to jam open, allowing the block to bleed down when the engine is switched off.

Oil pressure in the Vauxhall 2.8 Insignia turbo, the Opel and SAAB turbos, do not suffer quite so badly as an extra oil feed is taken from the Oil Cooler/Filter housing to the turbo. There is a "Boss" on the Oil Cooler/Filter housing, which is left undrilled on the Alfa.Had Alfa thought more seriously about how to make the VVT's work properly, not to mention the rear timing chain tensioner, they would have used this Boss as a supplementary feed for the block. One simple Oil Line would have cured the problem of lower timing chain tension, rear bank upper timing chain tension and balanced the feed pressure for the VVT's on both banks.