<VV> New heads, an approach...

[jvhroberts at aol.com]

As with all things, if one were to design a new head for the Corvair engine, there needs to be a rational and sound approach to it. Given that, here's my thinking:

1. Not everything GM did was wrong. 
2. Most of what GM did works pretty well!
3. To maximize marketability of this, the new design needs to be as close to a direct bolt on as possible. 
4. With these in mind, identify the shortcomings of the factory head, and identify the areas that can be MATERIALLY improved. Essentially, improve the factory head. 

With some of these as constraining issues, it does help simplify the engineering, which will be challenging enough as it is. 

Areas of improvement:

1. Cooling. Increase the number of fins to increase cooling area. Increase the open area. As contradictory as these two may sound, many aircraft engines have VERY thin machined fins to achieve these goals. With modern casting techniques (even some not so modern techniques!), I believe this can be achieved. 
The other cooling issue is the fan. Improving this is ESSENTIAL for a high output, especially a turbo engine. I looked at some 911 heads, and although they are more heavily finned than the Corvair head, they are not so, in proportion to their power output. Something line 30% more fin area on engines making 2-4x the HP. So, the fan, although a separate issue, needs to be addressed. 
2. Flow through the intake ports. CLEARLY this stinks on ice in a Corvair engine. Straighten the ports, add metal to allow bolt on manifolds, etc. Personally, I'd keep the original cast on manifold, and simply machine it off and drill and tap the bosses for those who want something else. Eliminates the need for a separate manifold for those who want to keep it easy and simple. Offer it both ways. 
3. Flow through the exhaust ports. Angle the port, and keep the port as short as possible in the head. Use pressed in steel tubes, as this actually works pretty well in both the stocker and certainly in the angled port engines. Keep the donuts, only because they allow some movement as things expand and contract. Bigger than stock, of course. And here, a better exhaust manifold/header is a must. 
4. Improve the combustion chamber shape. The LSx makes the most sense, as it's a proven design. Relocate the spark plug tip, but maintain the terminal end as close to stock as possible to allow use of stock shrouds. 

If someone thinks there are other major shortcomings, please, chime in, by all means!

>From where I am sitting, there's no reason why this approach, well executed, shouldn't work VERY well indeed. 

And the guys who just want something better don't have to make all kinds of pieces to bolt these on! And the guys who want to go crazy will have everything they need as well. 

>From a manufacturing standpoint, I was thinking of investment casting, but high quality sand casting may be just fine. And by ALL means, ALL finish machining should be done by an automated machining center, from both a quality standpoint and a cost standpoint. 

So, whatcha all think? Scotty got just about all of this in his design, I'm just trying to bring it home to as many buyers as possible.