Hello,
I did interesting test with ACdelco supercharger oil and Mobil jet oil.
I know ACdelco supercharger oil is same with Benz OEM oil.
Anyway I will not use jet oil to supercharger.


ACdelco supercharger oil VS Mobil jet oil







After 5-days later...
The cup filled with jet oil was melted.
I think it can break oil sealing mechanism of supercharger.




Below is my personal opinion.
"The amount of Jet oil of airplane is checked before and after flight by mechanic. Supercharger is not jet engine.
Jet oil can be used at supercharger, but after long time use with heat, it may break oil sealing system of IHI supercharger as it melted plastic on my test.
So the amount of oil should be checked as mechanics of airplane do."


I have used jet oil for 7-years and 40,000 miles(Total 120,000 miles) and found oil leak in this year.
I changed all bearings and seals, but still leaks.
If I can buy supercharger which has no leak, will not use jet oil.

 

You can buy a new supercharger from Benz if you like. They're only $2500.

Im more interested in the process to remove the snout off your blower. My 2nd blower has started leaking, the first one leaked too.

 

All dynamic seals leak - period. If they did not leak the seal lip would not last five minutes, the minute amount of leakage lubricates the seal lip.
Leakage will be more pronounced on superchargers that have a solid pulley retaining screw, the hole through the bolt keeps the pressure in the snout at the ambient atmospheric air pressure. Over ambient pressure in the snout would force oil through the seal lip if there was no hole in the bolt.

 

The AC Delco super charger oil is formulated for a roots-type super charger the kind of super charger utilized in the MB M111 inline 4 cylinder engine. The MB M112k v6 & M113k v8 engines utilize a twin screw super charger for which the AC Delco super charger oil is not specifically formulated.

 

Hello,
Thanks for information.
I think the difference of Roots or Tween screw type is compression method.
It is same that these have two rotating shaft combined with bearing and gear connected with one snout shaft which needs lubrication.
My point is that as Mobil jet oil melts plastic, it will affect rubber seal or break any tightness with longtime use.

Is here someone who expain why jet oil melts thin plastic cup?? Normal engine oil will not.

 

.

 

Some plastics are broken down by some liquids, while another plastic remains unaffected.
If the seal material was damaged by Jet Oil another seal material would be used.
You an buy seals made from different materials that are least affected by the liquid it comes into contact with.
Seal catalogs give ratings for various seal materials and liquids they could come into contact with.
Acetone dissolves ABS, styrene and Polycarbonate among others but does not affect polypropylene.
A thin layer of acetone on two pieces of ABS or Polycarbonate will allow the pieces to be joined together.
The acetone liquifies the plastic allowing the joint to hold together when the acetone evaporates.

 

180, Thank you very much.
You are an encyclopedia!!!
Then, mobil jet oil contains some ingredient dissolving a materials which is not compatible with.

In Applications of mobil jet oil, it says
"Mobil Jet Oil 254 is completely compatible with all metals used in gas turbine construction, as well as with F Rubber (Viton A), H Rubber (Buna N), and other commonly used seal materials.
(All of the builder approvals are aircraft engine builders) Clearly this product is for aviation use only (Turbine engines)"

I think "other commonly used seal material" is restricted to Turbine engines.
Mercedes supercharger is not turbine engine.

Applications

Mobil Jet Oil 254 is recommended for aircraft gas turbine engines of the turbo-jet, turbo-fan, turbo-prop, and turbo-shaft (helicopter) types used in commercial and military service. It is also suitable for aircraft-type gas turbine engines used in industrial or marine applications.Mobil Jet Oil 254 is approved against the High Thermal Stability (HTS) classification of U.S. Military Specification MIL-PRF-23699. It is also compatible with other synthetic gas turbine lubricants meeting MIL-PRF-23699. However, mixing with other products is not recommended because the blend would result in some loss of the superior performance characteristics of Mobil Jet Oil 254.Mobil Jet Oil 254 is completely compatible with all metals used in gas turbine construction, as well as with F Rubber (Viton A), H Rubber (Buna N), and other commonly used seal materials.
(All of the builder approvals are aircraft engine builders) Clearly this product is for aviation use only (Turbine engines)

 

In a previous thread you discuss Jet Oil (Ref:https://www.crossfireforum.org/forum...ngine-oil.html)

Clearly in that thread and this a lot of research has been done.

Jet engines run an average of 10 hrs/day with temps running between 1400C/2552F and 1700C/3092F The metals used in these engines begins to melt at 1300C Keep in mind long-haul flights range between 10 - 16 hrs non-stop. ONLY the materials, science, engineering and advanced cooling techniques keep them from melting and catastrophe failure. EVERYTIME an aircraft lands maintenance meets the aircraft and gives it a thorough post flight check. ALL engines will have oil loss for a variety of reasons.(side note the jet fuel burns around 2000C in the combustion chamber)
I don't understand the enthusiasm with Jet oil

Regarding aviation products, several owners use Nitrogen in the tires for less air leakage/loss and temperature fluctuations. Every 5-6 months requires adding about 3psi (36psi required )

 

Using nitrogen in the tires is a waste of money, air comprises about 78% nitrogen anyway. With just 21% oxygen in the tires oxidation inside the tires will be very slow.Filling the tires with air with little moisture in it is the best and cheapest. Using nitrogen ensures the absence of moisture and that is the best reason to use it.
Tires are replaced due to the condition of the outside of the tire if it has been run at the correct pressure. Use nitrogen if you want but when the tire pressure needs topping up you may damage the tire inside just driving around looking for a nitrogen source. ☹️
If a garage wants to fill my tires with nitrogen for free I would say yes, but I would not pay for it.

 

Thanks copperfieldkid.
The reason why I have enthusiasm with Jet oil is "Oil leak in my supercharger"
Not just scatter a little but sprayed a lot as below pic.
Also I found oil outside seal when I pulled out SC clutch.
Then I found it melts plastic cup so I suspected jet oil may melt rubber seal during long time use.
May the reason of leak is not caused by jet oil but in my experience and circumstances I have to doubt jet oil.
It's my personal opinion and I have no objection jet oil is good for turbine engine.
From now I will stop jet oil issue.^^ Thaks a lot.

 

oneHundred80, your absolutely right with the numbers and observation. There is a tire store three miles away that fills both my cars free. My Lexus came with nitrogen therefore I started using it in the Xfire also. If I had to pay each time I would discontinue usage. There are some that swear by it but I really don't notice any difference. Maintaining tire pressures is the key to tire life.

Ku95, maybe you should consider a future in aviation!

 

Your problem is a failed seal, it has nothing to do with the oil.
Change all the seals while you have the SC apart.

 

Dear, 180
I had replced all seals and all bearings(without snout needle bearing) two times as below picture.
The size of sealing was exact same with original but It still leaks a little as picture.
Last two suspectible reason was jet oil and snout needle bearing.
Now I recognized Jet oil is not the reason, then last one is needle bearing.
I think needle bearing was worn so the axis of snout was inclined by belt tension and it makes gap between seal and axis.
But I did not feel any play of snout axis at that time.
(I might be insensitive to feel the play)
Anyway it was big job to disassemble supercharger twice.
I will enjoy present condition checking oil amount in quarter ofa year untill next disassembling.

 

yes same thing happen to me, and since I am stubborn I try every brand seal available, that was about 7 times had to change that seal, guess what nothing worked eventually they all leaked few weeks later. Now the solution, just take the spring from another same size seal and overlapped over the spring on the seal your going to install. that solved for me, finally no more leak. I think that finally installed one from oringsandmore that had the highest psi rating over others they sell. that one has the strongest spring, then overlapped a weaker spring from other of the sames size seals I had bought. hasn't leak since that.

 

Hello,
Wow, 7 times replace...I respect you.
I inserted one smaller spring but it did not stop leak.
"Two spring" will tighten more around snout axis as you did.
Main reason of leak should be gap between seal and axis caused by needle bearing wear.
Fundamental solution may be replcement of needle bearing but two spring will be more easy way.
Thanks very much srt6prbk!!!
One more question, What oil do you use?

 

yes I think the oem seal is not available anywhere and it has 2 true lips to help seal the oil. the ones we find are 1 true lip and a small flap. the seals available have different springs rate, and I realize due to testing the strongest the spring the more it will last before dripping. 2 springs will compensate for the aftermarket seal not having the 2 true lips the oem had. I always use mobil 1 jet oil

 

FYI

 

Bottom line, don't use plastic seals.

 

What is the part number and maker of the OEM seal?
I doubt that a suitable seal cannot be found.