12v + 24v = ?

[OldCrank]

I'm sure I'm not the first to have this thought...

Will the 24v head bolt onto the 12v engine (assuming piston change for combustion chamber difference), or alternatively and likely more reasonably, will the 12v exterior fuel injection control mechanicals (non-electronic control) fit onto the 24v engine?

The thought here is to take advantage of the freer-breathing head design of the 24v and to retain the flexibility of the 12v fuel injection and air control. There probably would be issues to resolve of some sort, such as injectors, timing, intake and exhaust configuration, but that's part of the fun. What's the word on this? Thanks, BK

p. s. Uh, naturally all consideration would be given to maintaining correct and legal smog issues.

 

[Don M]

Actually the 12 valve head flows more air than the 24. So no advantage doing the swap as far as air flow goes.



A few guys, I have heard, did install a P7100 on a 24 valve engine. Dont know how it all turned out though.





Don~



12 valves still hold the high HP level wars as of now on #2 alone.

 

[cumminsgetme]

I agree Don, I'm not impressed with the 24V head. Comparing the two side by side it becomes pretty obvious.

 

[OldCrank]

Hmm, sure would like to get a pair of those heads side by side to see why Cummins would go to all the trouble to design a new head that fails to produce any of the advantages that should be expected. I'd heard that the 24v engine didn't produce any special hp/torque numbers, but I figured that it was related to fuel mapping and smog considerations.

 

[Don M]

For overall airflow and HP the 12 wins. I am sure the 24 is gonna give more low to mid power though.

I guess I was thinking you wanted to make a high HP motor with the combination you asked about.

Better combustion efficiency was the goal with Cummins. Not big HP.

I hear tell the 24 valver helped the emissions to lower as well. Prolly had more to do with the computer controled fuel system than anything.



Don~

 

[OldCrank]

Yep, horses is the goal. Has anyone you're aware of done any serious porting/polishing and/or valve resizing/cam profiling/rocker ratio type of analysis with these heads? I guess what I'm visualizing here is a fully reworked 12v/24v with one of the newer belt-driven superchargers to use for playtime at the local drags. It would be a huge (and $$) mistake to just start putting pieces together and hope they enjoy each other's company without looking for some folks who have done it first.

 

[gitchesum]

Go take a look in the Cummins conversion section of the boards. THere's a post by a guy that put a P7100 pump on a 24 valve motor and then stuffed the whole thing in a Hummer. Looked like a real nice install.



Here's the link

 

[Don M]

Yeah, Some guys have done port work and some have resized the exhaust valves to larger. All this in an effort to reduce exhaust gas temps. Joe D reported no gain from port work when he was at 400 HP. Maybe after 400 some gains could be had.

High lift cams are not available from the big aftermarket companies. I know several have custom ground cams like AutoWurks in New Jersey. I dont know the extend the cams have helped the HP.

Joe has said in the past our stock cams are pretty good after all for our Rams. He has pushed 609 HP with his and it used the stock cam. He has the record for top HP with #2 only.

The demand for hard parts like cylinder heads and the like is not great enough for the development from the aftermarket.



So... go design a cylinder head and sell the thing to us guys! hehehe!





The supercharger thing could be cool too, but I favor turbos because the parasitic load of the supercharger is too great even at low boost levels.

You end up making HP but loosing it through the belt turning the supercharger.



Don~