<VV> Re: synthetic in new engine

[Sethracer at aol.com]

In a message dated 3/29/2005 8:31:51 PM Pacific Standard Time,  
turbobraf at cox.net writes:

Problem  with the synthetic at the moment is my engine has only about 1,000 
miles  on a fresh rebuild, put chrome molly on the top ring, so could be 
awhile  before broken in, maybe 5,000 miles, it is still using oil, should 
not put  snynthetic in before then?  I do not understand how many new cars 
can  come out of the showroom floor with synthetic oil. Note that our vendors 
 
do not recommend synthetic oil until after the engine has broken in  
properly.

Bill Brafford



Bill - the reason new cars can come with synthetic is that new  engines (new 
design engines) are built to much closer tolerances than the older  motors, 
including our Corvairs. New design engines have rings that do not have  to 
"wear-in". They seal up immediately. Therefore they can come with Synthetic.  The 
new 2005 Chevy I am driving came with Mobil 1 from the factory. The oil life  
indicator built into it still shows lorts of miles left before a change is due. 
 - But I have had to add a quart of oil to keep the level up. It seems to use 
 some oil, but never smokes or leaks. It has just over 4000 miles on it. I 
will  probably change it at 5000 - just on principle!!
I ran synthetic in a Corvair engine for Autocross, because in the event of  a 
fan belt failure (not likely, of course - grin) I could still complete my run 
 without worrying about overcooking the valve train. The Synthetic oil would  
still lube the valve/rockers/balls at 400+ degrees oil temp - Regular  oil 
would have turned to mush - with the rockers soon to follow. If you have a  
street Corvair, the only way the expensive ($5/qt) Synthetics make sense is if  
you extend the change interval to a year. How much will you be driving this car? 
 If the piston rings have not yet seated leave the regular oil in until  some 
normal interval (be sure to run good oil - even non-synthetic should be SJ  
rated) then perform the changeout. The Corvair engine is not designed with the  
tight clearances needed to use the low viscosity (5W-20) oils, use the 
regular  viscosity, like a 10W30 Synthetic in normal driving. Of course, this is 
only my  opinion. 
 
Seth  Emerson
Sethracer at aol.com
C's the day! Corvair, Camaro,  Corvette