[Sudarshan]

^^^ IMHO your observation is correct -- I think the third one is the simplest , I remember that kind of thing on a V8 3.5 Landy I owned few years back & this kind is on a friends defender ( If I remember correctly ) both vehicles dont have pressure cap on radiator. the Caps were on the tank

Sudarshan

[headers]

^^ that is the modern way..

[fazalaliadil]

Originally Posted by DHABHAR.BEHRAM

I need absolutely no resistance between the radiator and the tank.

Now, since this has turned into a "official radiator- degas tank- overflow tank, thread".

Let me also learn.

My question to Sir Behram and others is as follows:

If I just remove the spring loaded, release valve mechanism which is calibrated at 0.9, would that not be sufficient for the flow from the radiator to the degas tank go unrestricted as compared to the present setup?

It will be simple solution, as the vent beside the radiator cap already discharges the flow into the tank with high pressure upon acceleration. Whatever resistance present due to the release valve in the cap will ease out and I can use the same cap without the spring.

Looking forward for inputs before my discrimination against the spring takes form.
Regards,

[headers]

Sir DB is yet to reply to my question some posts ago.

Or maybe he was teasing me.

I'm eager to understand the differences as well.

I would also appreciate if anyone could highlight one system from another

I think the system without the radiator cap is the best..

[DHABHAR.BEHRAM]

Originally Posted by headers

Sir DB is yet to reply to my question some posts ago.

Or maybe he was teasing me.

I'm eager to understand the differences as well.

I would also appreciate if anyone could highlight one system from another

I think the system without the radiator cap is the best..

What Vikram Saar, I don't TEASE anybody (I am a decent guy - you know! ). Lots of work and hectic schedules don't allow me to see the forum, let alone post on it. However, I'll be in flight tomorrow, when I'll open the laptop, type out the whole thing in word and then cut / paste to you all. I'll explain in totality, please hold for some time.

Best regards,

Behram Dhabhar

[Sutripta]

Originally Posted by fazalaliadil

Now, since this has turned into a "official radiator- degas tank- overflow tank, thread".

Hi,
This discussion should be interesting! (With the amount of experimentation Jeepers do, maybe we'll even go to reverse flow cooling systems.)

I really cant understand this setup. I take it that the radiator has a pressure cap. What sort of cap does the storage/ de-aeration tank tank have.

In any case, a lovingly maintained working (as opposed to show) vehicle.

Regards
Sutripta

[vishwaschettri]

@ Fazal saab - great outcome. I am a fan of all the jeeps done by you so far. Your attention to detail is immaculate. Its the small details which make a great vehicle. As they say "God is in the details".

As for degassing tank I have a few questions -

• How does such setup releases pressure in case it gets too much for the system to handle so as to not blow a hose? I am assuming that the reservoir bottle cab should be pressure rated if we are eliminating the radiator pressure cap.

• What is the benefit of this system over the conventional overflow bottle setup? As far as I can decipher this will only increase the amount of coolant (as much as the volume of bottle) circulating in the system thus better heat absorption / dissipation. Any other benefit?

• Can this system be retrofitted to other vehicles which only have overflow tanks ? or for that matter which dont even have that (read MM 550 with xd3p) My 550 can over-heat at times on long inclines. Where do the extra hoses go? A detailed explanation will be very beneficial to all.

cheers

vishwas

[fazalaliadil]

Originally Posted by Sutripta

I really cant understand this setup. I take it that the radiator has a pressure cap. What sort of cap does the storage/ de-aeration tank tank have.

Sutripta,

Thanks for your appreciation.

The storage tank has a pressurized cap with a release valve, but not the spring type. This tank is from Tata Indica.

Now I have been enlightened that the system is not efficient to its optimum due to the pressure cap on the radiator which restricts the flow.

Originally Posted by vishwaschettri

@ Fazal saab - great outcome. I am a fan of all the jeeps done by you so far. Your attention to detail is immaculate. Its the small details which make a great vehicle. As they say "God is in the details".

As for degassing tank I have a few questions -

• How does such setup releases pressure in case it gets too much for the system to handle so as to not blow a hose? I am assuming that the reservoir bottle cab should be pressure rated if we are eliminating the radiator pressure cap.

• What is the benefit of this system over the conventional overflow bottle setup? As far as I can decipher this will only increase the amount of coolant (as much as the volume of bottle) circulating in the system thus better heat absorption / dissipation. Any other benefit?

• Can this system be retrofitted to other vehicles which only have overflow tanks ? or for that matter which dont even have that (read MM 550 with xd3p) My 550 can over-heat at times on long inclines. Where do the extra hoses go? A detailed explanation will be very beneficial to all.

cheers

vishwas

Vishwas,

Thank you for your compliments.

The pressure cap on the radiator is calibrated at 0.9, this varies from manufacturer to manufacturer to suit the engine. The degassing tank cap is pressurised.

Increasing the coolant capacity plus heat dissipation due to circulation and air cooling is the main advantage, in my case a 2500cc XD3P needs more than the size of the radiator on my Jeep. Adding the bottle increased the coolant capacity by about 1.5 liter.

MM550 has a bigger radiator and also an oil cooler which helps in cooling the engine. Should this system be adopted on a 550 for an added advantage can be better explained by Sir Behram and Arka.

I will update here by adding more pics from different angles for clarity of the plumbing.
Regards,

[DHABHAR.BEHRAM]

Dear all – I am copying and pasting here, exact contents of my “Post No 36” which appears on “Page No 3” of the “Premier Padmini Technical Information Thread” in the “Post War” sub-section of the “Vintage and Classic Cars in India” section of this forum. This explains the critical differences between the surge tank and the degassing tank. Please read and interpolate the information as applied to Jeep. The radiator need not be cross flow, the system can be used with vertical flow radiator also:

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

[ex670c]

Originally Posted by fazalaliadil

Attachment 819347

Originally Posted by DHABHAR.BEHRAM

The radiator cap on the radiator is not required, it discontinues the flow through the circuit, please knock it off. Fabricate and fit a small metallic pipe to the radiator top tank at its topmost location and bleed the radiator into the degassing tank directly. Is the radiator top tank non-metallic? In that case, it is not so easy. For our prototypes, we get it molded from the tank manufacturer, the die is changed permanently. For one vehicle, you should be able to manage smething locally known as "plastic welding". Please call me in case you need assistance. In the worst case, as you and I want absolute reliability from our cars, you may need to go back to the copper/brass radiator. Then there is no issue to bleed the system.

Originally Posted by DHABHAR.BEHRAM

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.

Hello Sir,

wrt to XD3P with Oil Cooler, do we will need to add a T-Union to the Oil Cooler Line from the Water Pump and Connect to the Degassing Tank, to suck coolant from it.

Regards,

Arka

[fazalaliadil]

Originally Posted by DHABHAR.BEHRAM

Please give me your comments.

Dear Sir,

Thank you for the very detailed and descriptive information. Now, if Jeepers follow the info provided by you, will not their machines be a lot cooler?

I am attaching pics. of my circut layout, which if correct should compliment your write up and if not, the process of learning can still be derived out of it.

My mechanic had removed the rubber gaskets of the radiator cap when he installed the degassing tank, could this be the reason I see the pressurized (unrestricted) flow from the radiator to the degassing tank, upon acceleration?.

Also, all the way from Hyderabad to Lonavala, plus the 3 days of offroading in AKC & EXAMM and back to Hyderabad, the temperature gauge never went over 80, except for...on the long inclines and traffic jammed ghats from Karjat to Lonavala, where it went marginally over 80.

The traffic in Hyderabad as many know is heavy where I drive in 2nd and 3rd, yet the temp. stays below 80 without a (to be fabricated) radiator shroud.

Your comments please.
Regards,

[DHABHAR.BEHRAM]

[quote=fazalaliadil;2540472]Dear Sir,

Thank you for the very detailed and descriptive information. Now, if Jeepers follow the info provided by you, will not their machines be a lot cooler?

I am attaching pics. of my circut layout, which if correct should compliment your write up and if not, the process of learning can still be derived out of it.

My mechanic had removed the rubber gaskets of the radiator cap when he installed the degassing tank, could this be the reason I see the pressurized (unrestricted) flow from the radiator to the degassing tank, upon acceleration?.

Also, all the way from Hyderabad to Lonavala, plus the 3 days of offroading in AKC & EXAMM and back to Hyderabad, the temperature gauge never went over 80, except for...on the long inclines and traffic jammed ghats from Karjat to Lonavala, where it went marginally over 80.

The traffic in Hyderabad as many know is heavy where I drive in 2nd and 3rd, yet the temp. stays below 80 without a (to be fabricated) radiator shroud.

Your comments please.
Regards,[/quote]

Dear Fazal - my replies to your quotes are as follows:

Paragraph starting / ending with - "thank you / a lot cooler" - yes, of course as the physical quantity of water is more, so more molecules are available to conduct heat away from the engine. The thermostat will in any case control the delta of temperature. You are increasing system reliability at a cost, as you are doing only one vehicle, cost is not an issue.

Paragraph starting / ending with - "I am / derived out of it" - your circuit layout as shown in the diagram is completely incorrect, although you have connected the pipes properly. Your directional arrows are wrong. The "suction side" of the water pump is actually its delivery side. The "Indica pipe" location is the real suction side and as it is connected to the main outlet port on the degassing tank as it ought to be connected, the system is working properly. The additional outlet to degassing tank from the water pump outlet is not required. If you have it, it will not harm, but then you need to establish and prove system reliability which you cannot, considering the limited and non-standardized resources that you have at your disposal. As the radiator top tank is above this point, it is needless to bleed this point. Remember that when this pipe goes away, you will need to blank out the second bleed inlet on the Indica degassing tank, to enable it to build system pressure. The production Indica radiator is slightly below the engine, so two bleeds are required, otherwise the system will not bleed the engine.

Paragraph starting / ending with "my mechanic / upon acceleration" - what your technician has done is completely incorrect. By removing the rubber"s" as there are two rubbers, not one, (they all do it, don't they"? - nonsense!), he has bled the radiator to atmosphere. How will the degassing tank work? Your system is now "old gen", open type, except that the filler point has changed. The technician has no idea what nonsense he has introduced in the cooling system. Tell him to see Padmini S1 and learn! Also, tell him to see Indica. I am once again mentioning, what you need to do is completely remove the pressure cap from the radiator, seal the big hole somehow, introduce a bleed pipe at its topmost point and bleed it into the top inlet point of the degassing tank. That is the only correct way, there is no other way. During filling, when water enters, the atmospheric air must come out. Just because you travelled from Hyderabad to Lonavla and back does not technically justify your system configuration at all. Please also note that the degassing tank must not be filled fully. You must maintain around 700 cc (not 500 cc, I have done numerous experiments, so I know that it is 700 cc) of "air space", otherwise where will the cavitated fluid go and separate the "liquid from gas"? The whole intention of the degassing tank is to provide a "harmless release volume" to the cavitated fluid, so that the engine remains "liquid tight" under all conditions. Please read my post again, everything is explained very clearly. IF DEGASSING TANK IS INSTALLED PROPERLY, SYSTEM RELIABILITY QUOTIENT GOES UP TO A VERY HIGH LEVEL.

Dear Arka - for XD3P engines running to 4500 rpm with oil cooler, no additional connection is required as the "oil cooling fluid", in this case, the water circulates through hoses which are not affected by the addition of a degassing tank in any way. ("Elementary, My Dear Watson"). .

Best regards,

Behram Dhabhar

PS - Fazal - yesterday night, I was in transit at Shamshabad airport from 2000 hrs to 2330 hrs as my flight to Pune got delayed. As I was inside security area, I did not call you. If I knew beforehand, we could have met at the airport and I would have explained everything to you on ABD9294.

[headers]

Originally Posted by DHABHAR.BEHRAM

I am once again mentioning, what you need to do is completely remove the pressure cap from the radiator, seal the big hole somehow, introduce a bleed pipe at its topmost point and bleed it into the top inlet point of the degassing tank. That is the only correct way, there is no other way. ("Elementary, My Dear Watson"). .

Sir, I am aware of this system, Thanks for the wonderful explanation. Now, IFF, we implement this system in a 540 running 4.9 DP, can i add an AC to it? The common notion is the 2112cc peugeot cannot handle the additional load.

Also, what radiator type does NOT have a pressure cap? Can we just use the indica / indigo / fiat types or are we to buy radiators based on any particular rating?

[fazalaliadil]

Dear Behram Sir,

That was one hell of a trial and error, error on my part, but will rectify it after your most valuable inputs.

One simple question and expecting an equally simple answer from you.

If I manage to seal the same radiator pressure cap, faultlessly, make a hole on the top and attach a metal nozzle and connect it to the degassing tank with a flexible pipe, will it work? It will also be the top most part on the radiator, right?
Thanks and Regards,

[ex670c]

Originally Posted by ex670c

Hello Sir,

wrt to XD3P with Oil Cooler, do we will need to add a T-Union to the Oil Cooler Line from the Water Pump and Connect to the Degassing Tank, to suck coolant from it.

Originally Posted by DHABHAR.BEHRAM

Dear Arka - for XD3P engines running to 4500 rpm with oil cooler, no additional connection is required as the "oil cooling fluid", in this case, the water circulates through hoses which are not affected by the addition of a degassing tank in any way. ("Elementary, My Dear Watson").

Hello Sir,

You missed the elementary bit about Lines and their connections, because not all XD3P water pumps have 2 Additional Out Lets.

So if the only one is tapped/connected for the Oil Cooler, how do we connect the Degassing Tank.

Regards,

Arka