Cyl. Head Cross Section(s)

[Anonymous]

Is a 240 head cross section through intake and exhaust valves the same as a 300?

Does anyone have or know of accurate cross section pictures for either? I am planning to do some bowl work on a 240 head, and want to see exactly what I'm cutting into.

Without pictures, If someone could definately state that the two are of the same design and dimension, I'd be willing to buy a junk head, get it hacked, take pictures, and post for future reference. I'm guessing that I'm not gonna be the last forum member who's (insert adjective of choice - brave, ignorant, etc.) enough to try this instead of taking it to a "pro".

 

[Thad]

Guide line for porting 240 / 300 head are simple.

Blend bowl/ valve pocket, work short radius to more rounded configuration and then only smooth the floor and sides of port. Any enlargement ot the port should be in the roof tapering bigger from the top of the valve pocket to the port at the gasket surface.

It would be best to have your intake manifold handy to see how much you can open the port. The intake manifold IS a limiting facture. The head can be opened up larger than the available intake manifold can be.

Learned that the hard way the ID of my intake ports are LARGER than the OD of the runners on Clifford intake.