<VV> New Cast Aluminum Corvair Cylinder Heads

[Bryan Blackwell]

Hi Gary,

> We have a 110 head and 140 head at the pattern shop now.  The pattern
> maker has asked a few questions maybe some of you guys could help
> with:

If you haven't seen them, I think some of the GM engineering drawings for heads are available.  Getting things like the relationship between the head gasket surface and rocker stud the same as factory might be easier with them.  Answers/opinions inline:

On May 17, 2011, at 2:00 PM, Gary Rockwell wrote:

> 1)  Does anyone make new exhaust tubes for the heads?

I don't think so.  The only ones I know of are for the aircraft exhaust and use a different gasket flange.
> 
> 2) What compression and CCs should we plan for.  The head would need
> to be as univresal as possible becasue we can only make one casting,
> but there could possibly be some machining variations.

I'd shoot for 9.5:1 based on displacement of 2700 cc with no raised gasket surface, for good squish.  An improved combustion chamber would be nice :-)  It should be easy to remove some material or mill the heads from there to adjust compression.
> 
> 3)  What shape piston should we plan for?

99% of Corvair pistons are flat tops.
> 
> 4)  Does anyone know of an engine available?

I'm not sure, are you looking for one that runs to test with, or something else?
> 
> 5)  Is there a temperature sending unit threaded into each cylinder
> head?  ie Does each car have 2 temperature sending units, one on each
> head?

All heads have the boss for a temp sender, yes.  Spyders and Corsas used both.  Other than the balance tube for the carbs, the heads swap left to right without modification.
> 
> 
> Some notes of things most likely to be included:
> 
> Interlocking Valve Seats
> More free flowing exhaust port
> Closer valve seats with a larger Intake Valve
> Top of the Intake Manifold will be a bolt on plate so you may select
> carburetor or fuel injection configurations.
> Spark Plug will be directed at exhaust valve

Sounds great!

--Bryan