Author Topic: Enigmatic 3.2JTS  (Read 2598 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 »