Switching heads

[cade]

This may be blasphemy to MOST everyone here but I just have to ask this one. Would a 24 valve head fit on a 12 valve block (5. 9l). My reasoning is simple. Most larger diesels in over the road trucks use 24 valve heads. Has to be a reason. More flow? I know the 24 uses smaller valves (duh) and some say are weaker but maybe they have better flow. This way you can keep the big P pump... and not worry about the darn lift pump as well. Just thinking out loud... ...

 

[E7mack96]

The cam in a 12 valve will only run 12 valves, not 24. From what I understand, 12 valve cam has eccentric for pump, 24 valve cam does not, unless you want to shell out 2k for a cam to put a p7100 in a 24 valve motor.

 

[Deezul1]

From what I have read the 24 valve change was prompted primarily by EPA concerns. The 12 valve makes more power and gets better mileage generally speaking than the 24V

 

[Animal]

Piston problem

The pistons on the two engines are different, the bowl on the 12V engines are not centered like the 24V engines. You would have to change the pistons as well. As to the cam, just use an electric fuel pump but I'm not sure if there are any other differences in the cams.

 

[M Barnett]

I will have to disagree that most over the road big trucks use 24 valves.

Michael

 

[Garry Verheyden]

Cade,

The pistons would have to be changed, and you would not get as much flow out of the valves as you would with the 12v. A stock 24v might get a little more flow than a stock 12v. But if you put larger valves in the 12v you will get more flow than if you put larger valves in a 24v. I looked at a modified 24v with larger valves in it and you just can't get nearly as large valves in the 24v because the valves are already too close to the fire ring. From what I have heard, the two large valves in a modified 12v will flow more than the four smaller valves on a modified 24v.

Garry

 

[Joseph Donnelly]

To run the P7100 pump with 24 valve head you need custom injection lines and a few other tidbits. The 12 valve camshaft will run the 24 valves--look at the stock 24 valve setup sometime and you will understand.

In stock form, the 24 valve head might outflow the stock 12 vavle head. With the level of porting that is practical on both heads, I believe the 12 valve head will significantly outflow the 24.

 

[Animal]

Mr. Donnelly

Does the 24V and 12V cams have the same lift, if they don't can a 12V cam be used in the 24V engine for added lift.



Thanks