<VV> Looking for some advice on low compression

[Bryan Blackwell]

It's the extra material that seeps out between the casting molds.  In the case of a Corvair head, there was a top and bottom half, so the parting line is partway down the cooling fins.  Any flash blocks the cooling air, so we want to remove it to improve engine life.

See also:

https://en.wikipedia.org/wiki/Flash_(manufacturing)
http://autoxer.skiblack.com/heads.html#cooling

--Bryan

> On Dec 27, 2017, at 9:16 PM, Hugo Miller via VirtualVairs <virtualvairs at corvair.org> wrote:
> 
> Forgive my ignorance but what is 'flashing'? I'm from the UK originally & I'm not familiar with this term!