Engine/Transmission (1994 - 1998) 12V vs. 24V cylinder head

[400Magnum]

Hi all,



I'm working on a project for a class, where I'm trying to do an airflow study using the CAD model of the cylinder head to define my flow paths and areas. I have sort of already committed myself to doing a 12V cylinder head because I thought I had a CAD model for that head available. Now I find out that the CAD model is actually for the 24V.



My question is, can anyone tell me the differences in the air flow passages between the 12V and the 24V cylinder head, or at least point me in the right direction so I can find the information. Is the portion of the cylinder head from where the air enters the head the same on both heads?



I'm sort of bummed because I was hoping that I could find some worthwhile improvements that I could make to the OEM intake manifold that may be a cheaper alternative to the Banks Twin Ram intake. But if the cylinder heads are vastly different, then I don't know if improvements made using the 24V will transfer to the 12V.



Any help would be appreciated.



Thanks.

 

[Reb.B]

the air intake on the 24v's is the same as the 12v's. The exhaust is slightly different. The passage ways are different and more complated on the 24's. The twin rams don't do any more for our motors, . . u have to remember that the air going into our motors is compressed and not under vacuum. there are a lot of restrictions on out trucks, . . the intercooler that shrinks down to 2", the fins inside the tubes of the intercooler, then the inlet of the mainfold. If u need a 24v head i have an extra that has small cracks that i could send to u if u don't mind paying shipping.

 

[bighammer]

Sounds like a neat project. I hope you will keep us posted as to what you find out.



Glad to see another Michigan member too.

 

[JGK]

Contact Piers or Al. They ought to be able to tell you.



-Jay

 

[400Magnum]

Thanks for the replies.



If the project gets anywhere, I'll be sure to let you know what I find out.



Reb B. , Yes, I do realize that the air entering the engine is under pressure, but there's always room for improvement. The room for improvement in this case would be to more evenly distribute the air volume under high airflow (higher rpm) conditions. In a static or low airflow speed environment, there won't be much benefit to modifying the airflow entrance or path, as the pressure from the inlet charge air will tend to "overcome" obstacles in the flow path. However, as the flow speed (volume) increases, any obstacles or restrictions to flow do start to add up. My hope is to be able prevent the front cylinder from being air-starved compared to the other cylinders, especially under load like when towing or even just cruising at a high rpm going down the highway.



I know that the inlet runner to the front cylinder runs at an angle backwards from the direction that the air approaches the runner, essentially the air has to sort of reverse directions, more so than it would have to do with the other cylinders. This will theoretically cause the first cylinder to receive less air than the others at any given speed, and by the same process, if the rear cylinder has the same inlet runner orientation, it will receive the greatest amount of air. The greater the engine speed, the greater the difference will be in the air supplied to the cylinders as it goes from front to back. Of course, there are always ways to overcome this like increasing the boost pressure, but I was hoping to find a solution that could be applied to almost any truck, from bone-stock to very modified. I doubt that it'll make much, if any difference in power output, but it may help a little. The real benefit would be in potentially increasing durability and maybe smoothing out engine motion.



So, there's pretty much what I'm trying to do. I know that there are lots of things to consider, and that is all part of what the report is going to be about. I may come to the conclusion that there is no real difference to be found in real life dispite what the theoretical differences may be. But for right now, I'm just trying to determine whether the 24 valve head can be considered "close enough" to the 12 valve head for what I'm attempting to do. All of this may be a mute point, as the person that I was getting the CAD data from for the 24 valve head doesn't seem to be responding to my emails for getting the information. So, it might not go any further than what gets discussed here.



I may contact Piers to see if he can shed some light onto the exact differences between the two heads.



Hey bighammer, how's it going? I think there's several members on here from Michigan. I've noticed a few members here are from various spots all over the state.



Thanks for the replies!





Thanks again.