[Prabal]

Originally Posted by DHABHAR.BEHRAM

The Uno story - a very senior person from one of the automobile majors has resigned and started this.

Is that BVRS, ex-HMIL, by any chance? If yes, I thought he was getting into the components space?

Also Behram, didn't PAL have some sort of a tie-up with an American co. to redesign the Padmini body, and then showcased a few radically jazzed up versions in one of early 90s Auto Expos? What happened there?

[karlosdeville]

Originally Posted by Prabal

Is that BVRS, ex-HMIL, by any chance? If yes, I thought he was getting into the components space?

Yup, the plan was originally BVRs. What happened of it I dont know, as he announced the components foray after buying the Daewoo plant. Who knows, the Uno project might also be one, to tackle the Nano

[adheesh]

Also Behram, didn't PAL have some sort of a tie-up with an American co. to redesign the Padmini body, and then showcased a few radically jazzed up versions in one of early 90s Auto Expos? What happened there?

I think it was with AVL. The PAL plant in Kurla also had a S2 model of padmini (which was ofcourse one of its kind) designed by AVL. But it vain, a union leader (would not want to name) and his followers ruined all the plans .

Best Regards,
Adheesh Parelkar

[Prabal]

Originally Posted by adheesh

I think it was with AVL. The PAL plant in Kurla also had a S2 model of padmini (which was ofcourse one of its kind) designed by AVL. But it vain, a union leader (would not want to name) and his followers ruined all the plans .

Best Regards,
Adheesh Parelkar

AVL isn't American, but Austrian? It was some other company, unless I'm confusing the nationality! Moreover, AVL and FNM (of Italy?) tweaked the engines, the latter of course the clattery diesel mills in the 137D and the 138D. I'm referring to the body - inside and out.

This union leader I heard rode a Mercedes!

[SuperSelect]

Uno revival - Wow !! The Fiat Uno is hall of fame material in my gallery of "most respected cars". It'll be great to see it in production again.

The Uno brings a lot of memories back - in 1996, I had booked the Uno with Bombay Cycle and Motor Agency. Upon opening of bookings I was told that my Uno would take all of two years to materialize, such were the numbers ! The BCMA guys also tried to persuade me to buy a Padmini instead. Disappointed, I went and bought an 800.
Subsequently at a later time, I briefly owned an Uno Diesel, a sturdy and indestructible workhorse. She'll always remain one of my favourites. Uno rocks, guys.

[DHABHAR.BEHRAM]

Please read the result of my typing efforts at home in the last 4 days, copied and pasted here:

Conversion of Premier Padmini to run on a degassing tank equipped cooling system:

Why this need? – The original non-AC car is fitted with a pressurized (7 psi, upgraded to 11 psi) 3 row 75 tubes equipped vertical flow radiator assisted by a centrifugal water pump and an axial flow fan. The water pump has a design mass flow rate of 54 lpm (liters per minute). The fin density is around 10 fins per 25 mm of radiator vertical dimension. This system is very well capable of handing the engine’s cooling needs with good margin. The TD or "Delta T" as it is normally known hovers in the region of around 50 to 55 degrees C. Delta T is the difference in the temperature of coolant at it’s outlet point of the engine to ambient temperature measured under a standardized duty cycle. This is measured in 3 modes on plain road and gradient in GVW condition. However, this system although pressurized is not sealed. This means that as the coolant expands when heated, the additional volume will escape through the pressure valve of the radiator cap to atmosphere and will be lost forever. There are 2 methods to prevent coolant loss in this way. As usual, there is only one correct way. So, what are the two ways? 1 – Use of surge Tank. 2 – Use of degassing Tank. Both systems work. I will first describe both systems in detail and then I will tell you why the degassing tank is vastly superior to the surge tank. I will also provide complete procedure you need to follow to correctly fit your car with a degassing tank. Needless to state, this is an indicative procedure only.

The surge tank – see any Maruti 800 or Zen etc and the plastic bottle you will see there is the surge tank. So, how does it work? To start with, coolant is filled in the radiator as well partially in the surge tank. When the engine runs, coolant will expand. This expanded volume will escape through the pressure valve of the radiator cap into the surge tank. As the coolant surges into it, it is known as "surge tank". When the car is stopped, the coolant temperature drops, its volume reduces and tends to create a partial vacuum in the space that is leftover when the coolant contracted. This is when a small vacuum valve in the radiator cap opens and as its orifice is connected to coolant in the surge tank, coolant rushes back into the radiator against vacuum created there. This is the classical way to replenish the radiator. So, what are the system shortcomings? First, radiator cap’s valves must work perfectly. Going by the nonsense available in most shops, this leaves much to be desired. The radiator cap suitable for surge tank will have two rubber gaskets, one on each side of the outlet connection. If these gaskets do not seal out the atmosphere (specification of the rubber, quality of the rubber, parallelism of the joints, de-burring of the faces etc), atmospheric air will immediately enter the radiator and the surge tank will not operate at all and you will not know also. Second, in the best case scenario, imagine that everything is working perfectly. The surge tank still has a basic deficiency. Imagine a highway drive. Your engine is hot. The coolant has surged out into the surge tank. You stop at a roadside joint for tea for 10 minutes. Imagine what will happen. The coolant temperature drops by around 10 degrees in 14 minutes (it is known). Please note that the coolant temperature has not dropped sufficiently for the coolant to contract and go back to the radiator. The surge tank just cannot do its job. Third, even the best of engines is going to generate some cavitation due to internal cooling system micro-pressure differences and also through the water pump bearings (cavitation means a mix of coolant and air). The result of this cavitation has to settle inside the top tank of the radiator, as it is the topmost point. There is no other place for it to go. As mass flow continues to occur, there are distinct possibilities that this cavitation will be forced into the system again and again and come in contact with the cylinder block and head areas, which must remain free of cavitation for best performance and reliability requirements. This will create micro hot spots, which are not good for the health of the engine. Fourth, when the engine is running, the surge tank remains a passive part of the cooling system. It essentially does nothing. For all practical purposes, you can remove it and still merrily drive the car.

So, in order to overcome all these shortcomings, what to do? Essentially, operate the engine under a wall of coolant. This is exactly what a degassing tank does.

The degassing tank – see any Indica and the plastic bottle you will see there is the degassing tank. So, how does it work? Essentially, the beauty lies in the connection circuit diagram. The basic difference is that there is no filler connection on the radiator at all. The entire capacity of coolant is filled in the degassing tank. The degassing tank is designed and selected in such a way that it defines the topmost point of the entire cooling system including the radiator and the engine. Essentially if you draw a horizontal imaginary line passing somewhere in the middle of the degassing tank, all cooling system components including the topmost point of the radiator and everything else including the engine must perforce lie below this line. This is compulsory for the degassing tank to work. So, this defines the mounting location. Now, go to the circuit diagram. The degassing tank has to have an outlet connection of sufficient diameter, which is connected to the "suction side" of the water pump. Suction side is important. The first beauty is that when the engine is running, it continuously "sucks" coolant from the degassing tank, so keeping the critical water jackets pressurized with coolant. It is logical that if coolant has to enter the cooling system, air inside it must be expelled out otherwise coolant will not flow. The second beauty is that this system provides for a passive system bleed. It is a foregone conclusion that as coolant rises into the cooling system passages, any topmost point in the system must be bled (open to atmosphere). As you can’t just leave it open, it must be reconnected to the topmost point of the degassing tank. That way when coolant is being filled atmospheric air will be expelled through this orifice and through the open filler cap. The third beauty is that it is this very bleed which will provide an escape conduit for the cavitation to escape into the degassing tank where it cannot cause any harm. The fourth beauty is that the degassing tank volume is always decided in such a way that it must be filled partially. Some portion at the top of the degassing tank is the "expansion and cavitation volume"). The fifth beauty is that the filler cap although pressurized does not need two seals, as its outlet to atmosphere is natural. So the pressure cap does not become an overly critical design.

Procedure to convert the car - This procedure is indicative for vertical flow radiator fitted to a non-AC car, fitted with an alternator. For other variants, basic principles remain the same, however coolant inlet point may change. You will need 1 degassing tank. As the S1 came with it, nowadays you can easily pickup one from the scrap market where a lot of cars are broken down. Be careful to purchase the original filler and bleed pipes. These were supplied by Swastik rubber industries Khadki and are reinforced to handle cooling system pressure. The part number for the filler pipe is PAB48431 and for the bleed pipe is PAB48432. You will need 2 bleed pipes as the cut length may fall a little short. In order to increase its length, use a cut portion removed from the main fuel line of a broken down car. Do not use other pipes, if they do not withstand the pressure, they may burst on the road and lead you into problems. Purchase 2 nos. Marti Zen heater hosepipe clips, which will fit the filler pipe diameter perfectly. Use only Padmini S1 fuel line clips for the bleed pipe connections. Alternately you can purchase a brand new Indica degassing tank and adapt it but it is quite cumbersome to do it properly, as you will need perfectly fitting adapters. Remove the radiator and check for its general condition. Overhaul it if required. Then remove the filler connection from its top tank by heating it with a soldering apparatus (any radiator fellow will gladly do all this for a pittance) Take a piece of brass from a dilapidated radiator and solder it on the top tank to close it completely. Take one Solex carburetor fuel inlet connection, make a small hole in the topmost point of the engine side vertical face of the radiator top tank and inset the fuel inlet connection in it. That’s all on the radiator. Now take the degassing tank and attach it to the RH side of the dash panel so that adequate clearance is available to the steering gear drop arm to operate fully. You can use the M6*1.0 studs, which are available at this location which, were originally used to mount the mechanically controlled dynamo regulator. A simple fabricated bracket does the job quite well. As coolant capacity is around 2 liters and it must not be filled fully, load on the joints is not an issue. Just remember to keep the radiator bleed open when you will coolant and ensure that it bleeds through before connecting the pipe. Run the engine at around 1200 rpm. The water pump will suck the coolant down. Replenish it till around half capacity of the degassing tank and then fit the pressure cap. A pipe discharging to ground connects the cap outlet. Operate the car till normal operating temperature is reached and then refill coolant once again if required.

Please give me your comments.

Best regards,

Behram Dhabhar

[planet_rocker]

@ Mr Dhabhar - thanks a whole lot

it will be great if you can post High resolution pictures of the engine bay of either the LHS padmini or the red/black one - it will be great if the pics are clear and self descriptive. i am sure Cyrus will be able to help.

Thanks a tonne

ps: got hold of a NOS closed type radiator after a lot of search

[adheesh]

Very good piece of information. Will surely implement this after solving the spark plug blunder for which only I am responsible. Hope the issue is solved easily of else its going to be a tough time (You know what I mean).

Regards,
Adheesh Parelkar

[adheesh]

Discrepancies in the Padmini Users Manual.

As many on the forum may know that there were two kinds of Padmini Owners Manuals available. The pre 90’s one is a yellow and red colour thin one while the post 90’s one is a thick orange and peach colour one.

Coming to the point I remember my father (and even my grandfather telling my grandmother) telling me that the earlier 77 Padmini we had was performance wise much more better than the 91 model I currently have. Since I have heard the same story from different multiple Padmini owners, I decided to know the reason behind this difference.

The reasons may be:
1. Value Engineering Parts Used in the ‘91 model : Nothing much can be done about it so no point discussing it.

2. Different Ignition System: The earlier car came with a non-vacuum advance distributor (of course I know that the vacuum advance one is better). However the 77 car had a ignition timing of TDC (Top Dead Center) static advance. This means that the sparkplug fired when the piston was at the top most possible position. The ’91 car has a ignition timing of 10○ BTDC. This means that the sparkplug fires 10○ before the top dead center.

- Please Note: Since the camshaft profile in both the cars is the same (The intake valve opens and closes at 16○ and 56○ respectively and the exhaust valve opens and closes at 56○ and 16○ respectively) this change in the ignition timing may not be related to any change in camshaft profile.

However contradicting to the above fact, I remember reading in the Porsche 365 service manual that advancing the ignition timing (in reasonable amounts) can actually lead to performance gains.

3. Different Fuel Delivery System: The earlier car uses a PBIC Solex 1062 Carburetor but the new car uses a Solex Bicsa which is probably tuned for better fuel economy than performance. However from next week onwards my car too will run the older PBIC Solex 1062.

4. Difference in compression ratio : The ’77 car has a 7.1: 1 compression ratio while the ’91 car has a 7.8:1 compression ratio. Also my ’91 car has full flow type lubrication system.


Surprisingly the ’77 Padmini manual says that the power is 47 BHP while my ’91 Padmini says it is 42 BHP (39 BHP with 22mm Venturi and 97.5mm Jet; please read my earlier post in this thread for the details). I know that this may be for ARAI testing reasons and all this may not matter in the real world but however 5 (or 8) BHP is a great difference in power.

So my question is specifications mein itna difference kyon??

Please keep replying
.
Regards,
Adheesh Parelkar

[1100D]

Originally Posted by DHABHAR.BEHRAM

Now, go to the circuit diagram.
Behram Dhabhar

The Circuit Diagram please.

[umkomaas1221]

I would like to refer to ignition timing and explain the difference on these cars.

I am a specialist on Fiat 1100D, and all other manufactured fiat 1100/1200 engines.

All Fiat 1100(1089cc) engines, (103D, 103H, 103P) and 1200(1221cc) engines with reference engine numbers starting with, 103G000, 103G004, 103G005, have maximum centrifugal advance set to 30 deg B.T.D.C, + to - 2 deg, from about 2800 rpm, including all the Premier 1100(1089cc) engines.

However the only difference is the particular Premier Padmini engines that were fitted with the vacuum advance. On idle, the distributor ignition is set to 10 deg B.T.D.C, however from about 2800 rpm to max rpm, the timing becomes about 30 deg B.T.D.C., so the most important thing about performance is the setting of ignition timing from about 2800 rpm to max.

You could even tune this by ear from experience and see where the engine runs smoother.

There are also a lot of differences in compression ratios between engines.

I find that the best single downdraught carburetor is the genuine Weber 32IMPE, 4 or 7 or 10 series, in comparison to the SOLEX 32PBIC, For twin choke carburetors the best are the Weber 36DCD7 and 3 series which were fitted on Fiat 1100 Export, Deluxe and Fiat 1200 models.

You could even try the TWIN, SIDE DRAUGHT carburetor, which was fitted on the FIAT 1100R (1089cc) engine, you will need a FIAT 1100R manifold for this, or make one up.

Another important aspect in checking for correct engine performance is the complete INLET/OUTLET manifold gasket. I noticed that a few have been made incorrectly.

Kind Regards
Luigino.......

Originally Posted by adheesh

Discrepancies in the Padmini Users Manual.

As many on the forum may know that there were two kinds of Padmini Owners Manuals available. The pre 90’s one is a yellow and red colour thin one while the post 90’s one is a thick orange and peach colour one.

Coming to the point I remember my father (and even my grandfather telling my grandmother) telling me that the earlier 77 Padmini we had was performance wise much more better than the 91 model I currently have. Since I have heard the same story from different multiple Padmini owners, I decided to know the reason behind this difference.

The reasons may be:
1. Value Engineering Parts Used in the ‘91 model : Nothing much can be done about it so no point discussing it.

2. Different Ignition System: The earlier car came with a non-vacuum advance distributor (of course I know that the vacuum advance one is better). However the 77 car had a ignition timing of TDC (Top Dead Center) static advance. This means that the sparkplug fired when the piston was at the top most possible position. The ’91 car has a ignition timing of 10○ BTDC. This means that the sparkplug fires 10○ before the top dead center.

- Please Note: Since the camshaft profile in both the cars is the same (The intake valve opens and closes at 16○ and 56○ respectively and the exhaust valve opens and closes at 56○ and 16○ respectively) this change in the ignition timing may not be related to any change in camshaft profile.

However contradicting to the above fact, I remember reading in the Porsche 365 service manual that advancing the ignition timing (in reasonable amounts) can actually lead to performance gains.

3. Different Fuel Delivery System: The earlier car uses a PBIC Solex 1062 Carburetor but the new car uses a Solex Bicsa which is probably tuned for better fuel economy than performance. However from next week onwards my car too will run the older PBIC Solex 1062.

4. Difference in compression ratio : The ’77 car has a 7.1: 1 compression ratio while the ’91 car has a 7.8:1 compression ratio. Also my ’91 car has full flow type lubrication system.


Surprisingly the ’77 Padmini manual says that the power is 47 BHP while my ’91 Padmini says it is 42 BHP (39 BHP with 22mm Venturi and 97.5mm Jet; please read my earlier post in this thread for the details). I know that this may be for ARAI testing reasons and all this may not matter in the real world but however 5 (or 8) BHP is a great difference in power.

So my question is specifications mein itna difference kyon??

Please keep replying
.
Regards,
Adheesh Parelkar

[DHABHAR.BEHRAM]

Dear Mr.Umkomaas1221 - it is indeed very exciting and informative to recieve your reply. Yes you are correct, the Premier Padmini which we have in India has a 10 degree static advance which is different as compared to Fiat 1100 specifications. This was done specifically to be able to operate the car on a leaner mixture in order to obtain maximum fuel economy as possible. In India, this car is mainly used by taxi operators for whom fuel economy is of prime consideration. Also rudimentary emission norms came into effect in 1991 in India (similar to ECE15.03), for which delay valve and throttle opener were provided on the carburettor to reduce Hc and NOx. The Indian Solex PBIC is also tuned for fuel economy rather than power, therefore PBIC became BIC as the P (for pump) was removed. The India BIC also has an econostat and an internal vent.

As far as the Weber carburettor is concerned, I am still searching for a twin choke DCLD7 which was fitted on the 103ETV model but it is almost impossible to get it now. Even the side draft manifold is not to be seen.

Best regards,

Behram Dhabhar

[sushil_n79]

dear DHABHAR BEHRAM sir,
its been a really long time since i spoke to u. in fact i was out of country on a/c of some official wrk... well when i got bck to team bhp was really happy to know that there are thoughts abt relaunching the premier padmini. and i m sure that like its counter part the ambassaddor which is still going strong the premier will also be following the same trend set up by the ambassaddor.its all abt possibility thinking i will be going to bhopal this friday so will get the pics of my dad;s premier and will keep u infrmed.

I wld like to take this opportunity to sincerely thank you on behalf of all premier padmini fans for all the valuable suggestions u ve given to all of us in this forum
thanks once again.
take care
regards
Sushil Narayanan

Note from Mod : Please take the time to type out your posts in full words as per Team-BHP rules. Avoid the use of SMS language (wld = would, abt = about, etc). Thanks.

[DHABHAR.BEHRAM]

Dear Mr.Sushil Narayanan - nobody has mentioned anything about relaunching Padmini. In today's scenario (meaning emission norms + safety norms + customer expectations + JDPower CSI SSI and IQS demands), it will not be worth it. So although you will be disappointed, please remove this from your mindframe completely. I await details and pictures of your Premier Padmini in Bhopal. It is my pleasure to help and as you said if people are finding benefits, I am happy.

Please accept my best personal regards,

Behram Dhabhar

[kunaalsaigal]

Hi everyone... firstly let me congratulate you all. I am a die hard automobile enthusiast. I have grown up with Fiats in my family, and the last one my family bought was a 1994 Premier Padmini.

I always thought that I was passionate about cars but stumbling on your forums was a positive surprise.

A few days back I almost bought a 1957 Fiat 1100/103 from an old gentleman who had owned it for the last forty five years. The deal was almost through when the gentleman suddenly did not feel like parting with it. However for me the quest continues... so if anyone knows of anyone who wants to sell a Fiat 1100/103 1950-60 pls let me know. I can promise I will really take care of it.

Regards,
Kunaal Saigal
+91 9324594379