<VV> Synthetic oil, types , uses & seal compatability

[Silveyyevlis@aol.com]

Few people using synthetic lubricants  realize that there are at least  two 
basic types of synthetic lubricants. The lowest priced and probably the most  
commonly used one is Mobile ONE. ( there are other names but I don't recall  
them)  This type is made of regular petroleum oil but the molecular  structure 
or chains are modified by the addition mainly of carbon and other  elements.  
They are called pumped up hydrocarbons by some chemists.
 
These lubricants are very good but their characteristics are not good as  the 
true synthetics that are used in high temperature applications.  I do  not 
have much experience with Mobile One except in my portable air compressor  where 
I have had no problems. Mobile One probably is better for the production  
Corvair oil seals since it is basically a petroleum oil.
 
The other synthetic lubricant is called an ester based synthetic which is  
made from ester alcohol.  It is what is used in almost all turbine engines  
especially those that are flying. and many other high temperature  applications.  
I first used the ester based oil in my 67 
Monza at 90,000 plus miles and cut the oil consumption by at least  half.  
Ester based oils are not completely compatible with most automotive  seal 
materials. In my 67 I had no more seal problems than I had with regular  petroleum 
oil.  Also,  when the temperature dropped to minus 35  degrees in central 
Indiana our 67 Corvair was the only vehicle in the community  that started.   
However, my experience with an Allison turbine engine  where we used the lowest 
cost but satisfactory seal material with petroleum oil  we had no problems until 
we changed to ester based aircraft oil.  By  checking in a Parker seal 
materials catalog I found that the  two most  common seal materials that are 
compatible with the ester based oils are  Viton and silicon. We used Viton and 
eliminated the seal leak problem. Now you  know why I bugged the Corvair suppliers to 
get Viton crank seals for the  Corvair.
 
My 67 Monza was stored from 1989 until 2003. With fresh fuel it started  with 
no problems except the crank shaft seals leaked (not Viton).  The  brakes, 
with synthetic brake fluid, worked as good as when it was put in. Six  other 
Corvairs stored with the 67 had no brakes.
 
If I were to ever get to my 66 turbo convert ready to run it  will  be run on 
ester based oil and that will be Mobile Delvac II (two) or  equivalent.
 
The oils on the market that are a mixture of synthetic and petroleum oil  are 
no doubt good but I have no experience with them.  I called the  producers of 
 Valvoline and was informed that their mixture of synthetic  and petroleum 
oils did not use ester based oil.
 
Ams synthetic oil is an ester based oil and  is probably as good as  any 
available ( a little costly though).  However, I have used their  oil some but 
have used their synthetic grease ever since  it  became available and use it on 
everything that needs grease.
                                                                              
                                                           A WORD OF WARNING! 
 DO NOT get ester based oil on your paint or in  your generator or 
starter--it does a great job of removing paint and electrical  insulation. 
 
Hope this helps some one,  Tom Silvey