Engine/Transmission (1994 - 1998) 24v head on a 12v engine

[snowracer69]

I was just wondering if any one has put a 24v head on a 12v engine? What would be the advantage to doing this? I know that the 24v head has a lot more flow then the 12v head. If you had a donor 24v engine would it be worth the effort to doing a swap?



Things that would need to be changed:



1. Head - Would the 24v head bolt to the 12v block. I was told

that the 24v and 12v blocks are the same. Is this

true?



2. Pistons - You would have to change the pistons to 24v pistons

Would the 24v pistons work in a 12 engine? Is this

the only thing that you would have to do to the

bottom end of the engine for the swap of heads?



3. Fuel Lines - What would you have to do with the fuel lines?

Could you use the 12v/24v fuel lines? Would the

12v fuel lines work with 24v injectors?



4. Valve springs - I know that I have 60lbs valve springs in my

12v head. Would I need different springs in

24v head? What lbs springs are in a 24v

head?



5. Exhaust manifold - Would you need the 24v exhaust

manifold?



6. Anything else??????



Maybe I’m way out of line on this question. But thought that it would be a good topic to talk about. I did a search on 12v to 24v head swap but did not see anyone that has done this. All the people that I see have the 24v engine and want a p-7100. Would it be worth the trouble in doing this???? What would the advantage’s be and disadvantages.



Thanks, Lucas

 

[ronco]

Lucas, you can add a 24V head to your 12V block. There are a lot of things to consider, and I don't know all of them, so keep that in mind. My mechanic has done it.



1 The blocks are not exactly the same, but the top will have the same bolt pattern for the head.



2 I don't know.



3 Have custom made lines from a vendor. Vendor unknown to me.



4 24V heads have 60# valve springs from the factory. Use them.



5 24v exhaust ports are round, 12V ports are rectangular. Use the 24V manifold.



6 There is only a marginal increase in airflow for this mod. You must either want max. power or max cool factor. IMHO, if you want to go to this kind of trouble, convert a 24V to P pump. As was pointed out to me, there is a lot more interest from the vendors in making 24V H. P. injectors than 12V injectors.



The fact is, I know very little about these engines and diesels in general. What I know I have picked up here and have talked with mechanics that seem to be competent. Good luck on getting all your questions answered.



Ronco

 

[FreeBMW]

Pushrods need to be changed to I belive





Info from www.DodgeRam.org :





The head bolt patterns between the ISB and the B are the same. There would definitely be challenges in doing this swap, the most significant of which would be, in my opinion, that you'd have to fabricate a set of high-pressure injection lines that worked with the P7100 (for '94-98 trucks) and the ISB head.



The ISB's injector & line setup is different from any previous B-series setup, so you wouldn't be able to use old hardware to fit the ISB. On ISBs, the fuel lines attach to the "edge" of the head, and a high pressure fuel connector takes the fuel from the "edge" in to the center where the injector is.



You would also have to change pistons, since the piston bowls are offset in the B (due to the offset, angled injectors), but the bores are the same, so ISB pistons would fit w/o problems.



Some changes were made to the camshaft lobe proflies for the ISB, but they were made with several things in mind, including the 4-valve/cyl head and the variable timing capability of the VP44. I'm not sure what the right answer would be, but I'm not sure either cam would work well with the ISB head on a "mechanical" engine.



You may also need custom-length (or "adjustable") push tubes, since the tappets for the ISB are slightly different compared to B-Series tappets.



It's not impossible, just difficult (meaning, it'll cost $$$ to get right

 

[snowracer69]

Thanks for the replies. It sounds like it would take a lot more then I thought that it would.



1. I know that there are people out there running the p-pump on a 24v. Where are they getting the fuel lines? Are they all custom made? Somebody has to be making them any idea who is?



2. As for the push rods I did not think about that. So how hard are we talking about getting the right ones?



The only reason that I would even consider doing this is because I have a 24v head and pistons already from a wrecked pickup. There are some other parts on there to if I need them. The other reason I was thinking about doing this is that I want to run more boost and lower egt's already at 50lbs. So I’m going to have to pull the head and o-ring, port and polish the head. Figured that I would look in to doing the 24v head first since I already have one and don’t know if my 12v head is cracked or not.



I was doing some research on this and found out that the 24v head flows more then the 12v head..... What do you know I got a spare lying around not doing anything! The post that I read said that if you were do a stage 3 on a 12v head and a stage 2 on a 24v head that the 24v head would still flow more air then the 12v stage 3 would.



3. Does anyone now what the flow rates are on the 24v and 12v heads stock and stage 1, 2, 3???????





So the list so far to do this swap would be:



A. 24v head

B. Custom fuel lines (any one know of a vender that makes them?)

C. Custom push rods (how would you go about figuring out which ones to get?)

D. 24v pistons

F. Cam shaft (what cam shaft are the 24v guys running with the p-pump on there?)

F. What about the coolant flow anything have to be done with that? Will it all hook up to the 12v system?





Again thanks for all the info



Lucas

 

[KLockliear]

1. The head will bolt up to a Storm block without much problem.



2. Yes, you would have to swap pistons. The 24v piston dome is symmetrical, as the injector is directly above the piston. The 12v pistons' chamber is offset as the injector sprays in from the side.



3. Custom. I believe Scheids will build it, but don't expect it to fit right or look good out of the box. In the end, you might end up bending your own set from a set of test lines - but they will need custom ends for one end to fit a P7100 pump and the other end to fit a 24v head.



4. 60# springs are stock in the 24v. Those are OK.



5. Need the 24v manifold as well.



6. Anything else? My suggestion - don't even consider this.



I'm not sure who told you the 24v head is better, but from a performance standpoint, the 12v works just as well, and will make less EGT for the amount of power you are making. If you have a 12v now, you're already set. The 24v head was designed to meet emissions requirements, not for power.

 

[Todd G]

Sell the 24v head and get your 12v head ported. No expense and better flow.

 

[snowracer69]

I found this last night on piers web site.



#ad

 

[KLockliear]

CFM on a flowbench isn't everything.

 

[Sled Puller]

Figure out cost per cfm.

Then figure out HP gained per cfm.

Add in headache factor... fuzzy math... ... ...

 

[BV]

PDR (Piers) does the p-pump conversion on the 24v's so he would probably have or have a good idea where to get the lines.



I think before I would swap heads and increase the risk of cracking between the valve seats, that I would go with a stage 2 porting job.

 

[HoleshotHolset]

Haisley does the P-7100 - ISB head lines... . you have to order 'em, though. Prices and participation may vary, batteries not included.



Matt

 

[onestackdram]

you know i thought about this once. and since i have one of each in the driveway. the farthest i got on it was going out there opening the hoods and WALKING (didnt even bother to get up in there) and looking at both. I immediatly said phoowee on that. I would rather be down a truck for a day or two three at most i figure (provided I timed it right with the machine shop) than to even consider such a disaster.



JMHO



Russell

 

[zack_76401]

tHIS IS GONNA SOUND CRAZY BUT GO TO www.FORDCUMMINS.COM, THEY BUILD FURDS AND CHEVYS WITH CUMMINS IN EM AND OFFER THEM ALOT WITH 24VENGINES WITH THE P-PUMP. I THINK THEY SALE THE LINES YOU NEED. I HAVE A FRIEND BACK IN TEXAS THAT HAS A P-PUMP ON HIS OVERVALVER CUMMINS AND HE GOT THE LINES FROM THERE.

 

[T. Baker]

Another HUGE FACTOR is that you have to cut off the intake manifold area of the head to clear the P pump and fabricate a new intake manifold. Does that sound fun?

 

[KLockliear]

T. Baker, that is incorrect. You may have to clearance it a little, but definitely not cut it off.

 

[T. Baker]

OK I stand corrected but the guy who made a Cummins dragster cut the whole thing off and built a new one and stiched it on with small allen bolts threaded into the block. You can see it on his website

here

So how much do you have to cut off?

 

[T. Baker]

Here is a good picture

 

[KLockliear]

You don't have to cut much, if any. I would guess Scott did that to try to build a better flowing intake for it.



Here's a pic of one that wasn't modified: #ad

 

[sbentz]

No need to trim

Keith is right, a little clearance for the oil line, and other parts, and they fit. We did the P pump for the 24 v for ease of tuning. The intake manifold was something I thought would help for air flow, but now? Probably would not do again. Saved a bit of weight, and is easier to work on.



Talk about a lot of work for little to no gain, and if we need to change a head, start over.

 

[HoleshotHolset]

Did you see that thread I posted about the aluminum block/head 6BT's?



If you could get your hands on one... and make it run/last... . that would save you guys some weight.



Matt