I ask, because a guy is selling a 98 12 valve , &quot;that has a factory installed 24 vavle block&quot; said to have thicker cylinders for more strenght? I would guessto be false unless just the font covers are different....aren t the cam drives totally different?<br><br><br>

 

i was told by a very knowledgeable diesel tech at a chry. dealership that the 24 valve head would fit 96 up with the right parts. dont know for sure. sure could spend a lot of money finding out for sure

 

The 24 and 12 valve blocks are not compatible. The pistons have different combustion chamber designs, the crankshaft in the 24 valve is different and has a tone ring so the 12 valve lift pump will not fit, and the list goes on and on.<br><br>With enough parts and elbow grease, you could convert a 24 valve to a 12 valve, but the cost is outrageous (about like buying a new engine). I could never imagine anyone being dumb enough to go the other way and convert a 12 valve to a 24 for any reason, but it takes all kinds.<br><br>The 24 valve engine has thinner castings prone to cracking, so run the other way!

 

You would be kinda crazy to convert a 12v into a 24v. First thing is that a 12v has so much high performance stuff you can do to it with out the electrical crap. If I had a choice between a 12 and a 24 I would pick a 12. <br>SD03

 

SD03,<br><br>A 12V motor would benefit quite a bit from a switch to a 24V head. You can put the 24V head on a 12V block with a switch to 24V pistons and the associated 24V/custom head hardware (injectors, lines and such) while keeping the P pump. On the flowbench a stock 24V head flows better than a ported 12V head, so that increase in airflow can only help.<br><br>John

 

Banshee,<br>Is there much difference between the 12V and 24V injectors? Would a 24V head on a 12V with P-pump have any problem with the pop-off pressures on the injectors being different (assuming they are different since the 24V pump is rotary and the P-pump is inline)? <br><br>Don't know, haven't looked into it that far, figured I could ask and learn something......<br><br>Also, the 24V intercooler flows better than the 12V unit - reckon they had to up the flow with the heads being so much better.

 

There is a significant difference between the 24 valve low pressure injectors and the high pressure units used by a 12 valve. You can pick up a set of 24 valve injectors rebuilt for the P pump pressures, but my experience is that the 24 valve heads will not stand the additional pressures of the combustion cycle if you try to up the fuel feed. It will break between the exhaust valves, and dump coolant right in the cylinders.