I decided to perform some minor cylinder head porting and polishing when my engine was apart for a minor overhaul. Researching the forums and looking at common practices with high performance motorcycle and car engines I decided to do some basic cylinder head modifications. If you have any questions or comments pls post. Are there known porting or valve rework technics that help to make our trucks flow better?
The exhaust port recieved the bulk of the work. Matching exh ports to exhaust manifold this resulted in a 3 mm larger port. Open up the bowel below the valve seat. The short side radius of the port is horrible and no easy solution it is just about a 90* turn.
A standard 3 angle valve job and thats about it.
The intake ports in the head are a fairly good size but I am unfamiiar with this swirl port head design. Googled it a bit and it seems this similar to the vortec heads from GM.
Minor cleanup of the ports with alot of material removed from the inside diameter of the valve seat insert. The insert was creating a 1mm step right before the valve seat which causes turbulence of the intake air just before trying to enter the cylinder. I enlarged the inside diameter of the insert almost 2.5mm. The intake was finished off with a 5 angle valve job.
The intake manifold ports are considerably smaller than the ports on the head. I die ground a radius as large as a I dared because the manifold is paper thin. See pic of gaskets to view the difference
Stock valves were ground back to spec and seats were cut using a Neway cutter set. I also back cut the valves.
The focus of the valve work was to improve low lift flow.
I am not an expert cylinder head builder. The work performed is what I thought was best for my application.
So far so good I am very happy with the way the Cruiser is running.
The 2H/12H-T/1HZ/1HD-T/1HD-FT Gturbo Alternative Tech Thread
I used information from David Vizard,s book
Developing Highly Functional Cylinder Heads for Performance Applications - Part 10
The exhaust port recieved the bulk of the work. Matching exh ports to exhaust manifold this resulted in a 3 mm larger port. Open up the bowel below the valve seat. The short side radius of the port is horrible and no easy solution it is just about a 90* turn.
A standard 3 angle valve job and thats about it.
The intake ports in the head are a fairly good size but I am unfamiiar with this swirl port head design. Googled it a bit and it seems this similar to the vortec heads from GM.
Minor cleanup of the ports with alot of material removed from the inside diameter of the valve seat insert. The insert was creating a 1mm step right before the valve seat which causes turbulence of the intake air just before trying to enter the cylinder. I enlarged the inside diameter of the insert almost 2.5mm. The intake was finished off with a 5 angle valve job.
The intake manifold ports are considerably smaller than the ports on the head. I die ground a radius as large as a I dared because the manifold is paper thin. See pic of gaskets to view the difference
Stock valves were ground back to spec and seats were cut using a Neway cutter set. I also back cut the valves.
The focus of the valve work was to improve low lift flow.
I am not an expert cylinder head builder. The work performed is what I thought was best for my application.
So far so good I am very happy with the way the Cruiser is running.
The 2H/12H-T/1HZ/1HD-T/1HD-FT Gturbo Alternative Tech Thread
I used information from David Vizard,s book
Developing Highly Functional Cylinder Heads for Performance Applications - Part 10
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