<VV> lead additive

[Sethracer at aol.com]

In a message dated 9/3/2007 9:11:44 A.M. Pacific Daylight Time,  
mhicks130 at cox.net forwarded:

>  I've always been under the impression that I needed the lead additive for 
my  64 Spyder.  Now someone says not so.  Do I or don't I?  It is  not 
expensive but every little bit helps.
>  *******************************************

No, you don't.  And  you never did.  As previously stated, it's the hardened 
valve seats that  make that so.  The water coolers of the day had the seats 
machined into  the cast iron head - softer than ours (but they don't fall out).

Lead  is also used to increase octane so you do still need to make sure 
you're not  pinging with the gas you use.

mikeH



Mike is correct. Corvairs never needed "Lead" additives. What you have been  
adding is a Lead substitute additive. Those additives are needed for the 60's  
cars with the fore-mentioned valve seat recession problems. The lead acts  as 
a cushion for the valve when returning to the softer cast iron seats. Later  
cast iron heads used hardened areas to prevent it. Our Corvairs use separate,  
harder, seats installed in the aluminum head (as do all other aluminum head  
motors). The cushion isn't needed for our motors. The original lead added to  
motors since the 1940s (30s?) was intended to raise the effective octane of 
the  gasoline by retarding combustion speed - limiting spark knock - on higher  
compression motors. Current all-out racing gasolines still use similar  
additives, all toxic to catalytic converters, that is why street use is  restricted. 
You can buy unleaded gasoline at well over 100 octane, I think  104 is the 
highest I have seen, but economics prevent general distribution of  them. Racers 
that still are required to run converters use them. The  Corvair motors - 
with the possible exception of the 80HP motor - prefer higher  octane gas. I have 
always used 91 Octane - The California equivalent of the 92  Octane in most 
places. If your car will run well on 87 octane, do it. If not, go  up until it 
is happy. - Seth Emerson 



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