Navarro 8ba Heads

[69a]

Originally Posted by Shoebox

I asked Mike about this subject, his response below.

On Jun 3, 2026, at 9:23 AM, Mike Herman <[email protected]> wrote:

 The electrode is not supposed to hanging out in the valve pocket or it will hit the valve

When the exhaust valve is fully open there is less than 1/16" gap between the valve and the cylinder head. This means the entire plug is up inside the thread. I have seen some heads where a recess is cast into the combustion chamber. The Edelbrock combustion chamber pictured in my previous post has a CNC machined recess to allow for the electrode to extend into the combustion chamber without hitting the valve. The Edelbrock combustion chamber looks great, the other one, not so much.