<VV> Re: Rockers

[Sethracer at aol.com]

In a message dated 11/26/2006 5:34:22 PM Pacific Standard Time,  
wblanning at adelphia.net writes:
 
a question about your VV subject note.  You said:

"That  is why the Corvair rockers have special intake and exhaust and even 
special 140  rockers, since the plane is different in the 140 head. "

This implies to me that there is a specific rocker for intakes and a  
different one for exhaust, as well as specific rockers for 140 engines.  I  thought 
they were all the same?  

Tx,
Wade
 



Good catch Wade!  I better add this to the note:
I was referring to the aftermarket Roller-Trunion rockers, not the  stockers. 
The only engine specific rockers on the market are the SC Performance  origin
ated aluminum rockers. (PS - No matter who sells them, they are the SC  
Performance design) The manufacturer sells them through other retailers as  well. 
There used to be several other Corvair aftermarket rockers available,  Crane and 
Norris (Not Rick!) were suppliers. Clarks even sold a shaft-mounted  set-up a 
few years ago. The stock rockers can be used on either the intake or  exhaust 
- There was a change in the Chevy supplied rocker arm sometime after the  car 
was discontinued. I cannot pinpoint when. The Chevy supplied (through the  
parts dept) rocker in the mid-70s was definitely different than the ones which  
were installed on the line. The easiest way to tell is to inspect the ground  
area that contacts the valve tip. The originals were narrower and longer. The  
later ones were wider and shorter. Many racers have searched out the earlier  
ones, provided the contact patch was "non-dimpled" - you engine assemblers  
know what I mean - and used those. For use with high lift cams, the slot in the 
 bottom of the rocker for the stud needs to be elongated a bit to allow full  
travel. I am working on a replacement roller-tip rocker for the Corvair. 
Slowly  (but surely) marching toward production, I hope. - Seth  Emerson