Dissection of a Stock Head
Casting number 25518445

The Cuts

Features of Note:
  • This is a stock 1987 25518445 casting head that is cut into the sections shown above
  • From these cuts we can see both profiles and cross sections

Cross Section of Chamber

Features of Note:
  • This is an interesting view and shows the cross section of both the intake and the exhaust ports in the bowl area
  • Notice the relatively "U" shape of the exhaust port, while the intake is more convoluted

Profile of Exhaust Port

Features of Note:
  • The exhaust port is relatively straight and should flow fairly well
  • Notice the short side radius and how close it comes to the water jacket. If you are porting and take too much material off on that turn, you're likely to ruin the head
  • Notice the water passages around the valve guides to cool them. It also reduces porting in that area.

Profile of Intake Port

Features of Note:
  • The intake port isn't nearly as straight as the exhaust port. It bends and twists around the head bolts
  • There is a lot of meat in the bowl area that can be removed, but the floor is relatively thin
  • Notice the water passages near the floor of the port

Submitted by:

Freddie Williams