939 Premature Redundancy

[Ascari32]

It is clear to me, there is a genuine affection for the 159, Brera, Spider and Sports Waggon in Australia, more so than I think in UK. But whilst the Bertie, Alfetta 2.5 GTV6, 916 GTV, 147 and 156 GTA's acquire almost legendary status - of which I think the 2.5 GTV Alfetta, Bertie and 155 deserve to be lauded - the 939's languish, almost ignored completely as nothing seems to be done to raise their profile by way of performance enhancements.

And it is not as if they aren't very good cars. But weight and lack of horses under the bonnet, is always cited as the main reason for their dismissal. But throughout my ownership of Alfa's, it has always been the case that more could be rung from every model. And this is equally true of the 939 series, but little attempt has been made to do so.

I do not class those who supply "Cat - back systems, as after market specialists. Or those who claim incredible performance gains from software modifications,  when the limiting factor is always going to be the mechanical design. I find it bizarre that the first quad cam V6 Alfa, with chain driven VVT's should be so poorly regarded.

Not only have main dealers and Alfa in Particular treated them as the "Fatted Calf", I believe the majority of independents have also dined out by creating the illusion they are more complicated than any other manufacturers offerings.

With this in mind, although I continue to avoid software modifications, I do not believe they are necessary for cars which have been less extensively modified.

I have come to the conclusion, folks will only step up to further modifications, if they can see a genuine increase in performance from the most modest of changes. And one area in particular, which will give a definite "Step - up" in performance is changing camshafts. But in this I am now convinced it would only require a change of inlet camshaft. And with this in mind, I have contacted MACE, who manufacture cams for the 3.2 JTS engine. Being made in Aus, they are considerably cheaper than any European equivalents and for just a pair of inlets, they would be very - very cheap for the performance they would generate.

Having designed a set of VVT support brackets, to facilitate cam changes, the task can be; in every sense of the word, easy. Probably 3 -4 hours labour at a competent garage. And the uplift, from my experience would more than justify the expense.

It, of course requires a Guinea-pig, just as it did when I supplied one of your compatriots with my "Closed Loop Lubrication System", which he has been running on his 159 for some three years now, without fault. I shall approach him again, to see if he would like to take further part in this project and will of course supply the tools and the technique details to make it go smoothly. But this very much depends upon what MACE have to say. They give very little by way of technical details, but I have asked for more clarification.

Should they decline to take part, then the alternative approach would be to have the Alfa Inlet camshaft re - profiled and exhaust hydraulic lifters fitted in place of the current inlets. This would be done on a camshaft exchange basis, just as I did with Richard. I await a reply from Colombo Bariani about this issue. However, they are adamant they will not add metal to lobes as any welds could break with disastrous consequences. So the solution I propose is to use the exhaust lifters, which have a height of 37mm. in place of the inlet lifters, the height of which is 34mm., which then provides 3mm of excess meat to reprofile the Alfa camshaft. In essence, this is probably the best solution as C.B. will choose a profile they "Know will Work". But it will be more expensive, unless I can persuade them to do it as part of the research.

A condition, to which Richard; a compatriot of you Aussies agreed to, was to have his car Dynamometer tested before my modifications went on his car, and after. The same condition would be required of anyone who volunteered. Colombo Bariani would insist upon it and I suspect MACE would too.

"Results can be Greater than the Sum of all Parts" is the old adage I like to use in these situations. But who will be willing to test the theory?? Anyone interested can P.M. me and can rely up absolute discretion, if that is what they choose.             

[Ascari32]

Alfa Romeo
home cars camshafts Alfa Romeo 159 - Brera - Spider 3200 24v JTS : AR24H.SM1
specification
product codeAR24H.SM1

camshafts1 x AR24H.070.278.A1
1 x AR24H.070.278.S1
1 x AR24H.070.278.A2
1 x AR24H.070.278.S2

useRoad medium

In/Ex cam lift7 / 7

total degrees278° / 278°

distribution phase/

lobe center/

lift at TDC In/Ex/

valve clearancepunt idrauliche / punt idrauliche

price
€ 2.290,00 + VAT

the price is referred at the product set and is without VAT and transport FEE

Alfa Romeo : 159 - Brera - Spider 3200 24v JTS
The road profiles offer a good compromise between the various daily use needs of an automotive engine: regular minimum, good torque at a low rpm, low exhaust emissions and a significant increase in maximum power.
The profiles for racing use offer a substantial increase in power at high rpm, guaranteeing typical performance of a racing vehicle.

Some of the parameters on which action is taken to improve the performance of an internal combustion engine through camshafts with a new profile are the increase in the lift of the valves, the increase in the crossing values ​​of the exhaust and intake valves and the duration of the cylinder filling phase. Through a correct design of a profile from the correct mix of these parameters, an improvement of the engine performance in relation to its use is obtained.

specific note for the product
Made on request

Thanks for your swift response.

However, these camshafts are designed as a straight swap - out with no need for remapping. Colombo Bariani clearly state this in their technical section. The problem for me is much more specific to the changes overall, which includes the Autodelta headers and the 100cpi Supersprint Sports Cat. And testing carried out by myself, before the replacement of the Alfa Twin Cat, Central Resonator and pipe bore this out. The issue was not about software, it was the inability of the central resonator to handle the increased power, being exacerbated by the poor design characteristics of the Alfa Twin Cat. The drone at 2500 rpm was just louder than standard. But that drone is a character of the standard 159 3.2 JTS, the very reason Alfa included it in the first place! There is no droning now, but the back boxes create an issue for transparency - through-flow from exhaust to inlet due to the 23.5deg. PVO the C.B. Quad - cam set up introduces, which greatly influences the MAF.

This influence will be virtually none existent with the standard Alfa exhaust system, with the man - cats and central cat buffering the influence: because these elements are so restrictive.

Although VE is improved by just just changing the cams, this changes dramatically when one includes all the other changes I have made. But the principal of the proposed modification of just the inlet camshaft will not create the need for a remap. The valve timing will change from 11.5deg. ATDC inlet opening, the exhaust having closed at 9.0deg. ATDC, to 0.5deg. BTDC inlet opens and 9.0deg. ATDC exhaust closes.

The biggest change being the inlet air is not checked/halted due to the 2.5deg. NVO and the cylinder fill will begin at top dead centre instead of 11.5deg. ATDC. The 12deg. extra opening time and 12deg. later closing time will improve the VE considerably. But not to the same extent as a full set of C.B. on inlet and exhaust.

This is where my problem lies, but a solution is at hand. If I replace my C.B. exhaust cams, then this issue will reduced. But what is being proposed is toy leave all other components in place and just change the inlet camshaft. That is not possible with my car, to restore the status quo at considerable expense and then to restore it again. And that is on the pretext that someone would be willing to implement the inlet cam swap on their motor!!!! Not wishing to be rude - but I have been there before.

The changes made to my car are permanent, with the caveat that Colombo Bariani will be getting the results of the Dynamometer plots.

The agreement I had with your compatriot - Richard - was it would be at cost, and the modification, had he not been doing his timing chain system, would have been a lot more expensive than what I am proposing!

What is even more remarkable about Richard's commitment, he covered the cost of possible loss in transit - both ways, by depositing a substantial amount in my bank account - refunded on completion of exercise and safe return of the exchange items.

Now, is there anyone who would be prepared to upfront the cost of my camshafts? I shouldn't have thought so! But certainly, if I supply the camshaft sprocket tool, seen in the attached picture, the cost of that exercise is not going to be a rental fee, just the amount it would cost me to have them remanufactured - refunded on safe return to me.

Colombo Bariani have said, to reprofile all four Alfa Cams would cost about £700.  A pair of Supersprint Back boxes are over £800!!!! So the cost of this exercise will be down to the cost of a pair of MACE cams, which I would expect them to be delivered locally. This is on the assumption their angles and duration meet spec. If not, then I must send my spare inlets to Italy, then have them shipped to any would be guinea pig. On completion, the guinea pigs inlets would be returned to me. Again all at cost.

I really don't see what more I can propose. I accept the real reason so little "Tuning" is done with these cars is because of cost and the general lack of understanding about what can be gained. But if I was to retro - fit my parts, back to standard, completely, I couldn't see that would persuade anyone either. Which is why Richard is such an outstanding character. He had a lot less to go on, to justify his faith.

However, there will be considerably more enthusiasm if a Forum member was to see what can be achieved first hand. Beyond this, I have no wish to become further involved and individuals would be free to speak to C.B. or MACE themselves.