Cylinder Head Steam Vents

There are a lot of theories regarding the steam vent system of the LS engines, and whether to leave the rear 2 blocked off or not.  The theory is that air pockets form in the top of the head and can create hot spots.  I think it depends on how level your engine is whether you should have them open or not....

I decided to play safe and buy a steam vent kit from the USA which links all 4 vents back to the header tank.  I had to relocate the N/S lambda sensor connector bracket that I placed over one of the ports.  I just made a new stainless steel bracket to mount it and bolted it to the block with a short M10 cap screw.

This also meant that I had to drill out the small plug that blocks off the port on the rear of both cylinder heads.  I used a 3mm drill bit with lots of grease and a hoover to slowly drill out the plug.  Once I was down a little bit, I tapped the hole out to put in a M4 bolt.  This then allowed me to plug out the plug without causing too much mess!

I gave the water jacket a good hoover, to ensure no swarf had entered in.

I plugged the holes with paper towel temporarily to prevent any further entry of bits.  I will provide an update once I have fitted the steam vent kit.