<VV> 80 vs 84 vs 102hp head confusion

[BobHelt at aol.com]

In a message dated 12/22/2011 1:06:41 P.M. Mountain Standard Time,  
corvairgrymm at gmail.com writes:

So  first, can anyone confirm my belief that the 84hp heads are not the same
as  80hp heads but likely are the same as 102hp heads?  This means  Clark's
catalog needs a correction if it is true.  Second, can anyone  tell me what
is going on with the "machining numbers" in the tech guide  chart matching
what should be casting numbers in the Clark's catalog and  Junkyard Primer?


Thanks,

-- 
Ray "Grymm" Rodriguez  III





Ray,
The 84hp and 102 hp engines both used the same cylinder head. The 80hp  
engines used a different head. The 80 was an 8:1 CR while the other head was a  
9:1 CR. Castings were different.
 
You will find a lot of discrepancies in head number listings. But Kirkman's 
 lisings in the Tech Guide is the authority. All other are suspect to some  
extent. It's a complicated story and we still don't know the applications 
of  some heads kirkman lists.
Casting numbers identify the rough and unmachined head. Several different  
heads often were machined from a single casting number. Use Kirkman's list 
but  be aware that not all heads he lists received production status. the 
list  includes prototypes and experimental types too.
 
If you want an analysis of Kirkman's listing, please see a copy of my book, 
 CORVAIR SECRETS.
 
Regards,
Bob Helt