4age bigport head: port & polish

[BenR]

Os7213 Wrote:Hi BenR I got a question about your porting job..Why do you remove material all around the cylinder bore line around the chambers?:


(For the image can you right click and open it i dont know why the image dont work when using left-click sorry )

Or can you tell me what serve this deck and how much material have been remove from Z axis?

Here my second question, i projected a porting job on my 4age smallport 16v head , and here my idea for the chambers... My idea is to reshape the chambers to the cylinder bore-size for more sqish area do you think this is a good think or it will ruin the head?



Sorry i hope im not too off topic since the question is about porting.

Thank a lot in advance
Ugo

Ugo, sorry it took me so long to reply, but i do not check on here that often.

The Chambers were recedded in the quench areas because we were running a special piston combination that saw them sit 20 thou proud of the deck face.

And in my opinion, do not open up the side of the chambers to the cylinder bore size like your drawing indicates. You want to run the smallest piston intruder as possible, and the larger you make your chamber, the larger your intruder has to be, which impedes flame front propagation.

In our extreem applications we actually weld the head into cloverleaf design and run a specific piston to maximise the quench area available for effective combustion and to reduce the chamber size so we can run less ignition timing and a faster burn.