What if any are the block differences between a 2nd gen 12 valve and a 2nd gen 24 valve block...Thanks

 

one right of the top of my head is the 12v block doesn't have the dip tube boss cast into the passengerside pan rail.

 

Reason for question is need to rebuild 12 valve engine with 53 block, but have the opportunity to purchase a non 53 24valve block, ready to be reassembled for cheap.

 

If memory serves the biggest difference is that the 24v pistons are different form the 12v pistons, also the injection pump gears are different. Other than that I think it's a pretty seamless transition.

 

The 24-valve block uses metric instead of SAE fittings for oil pressure sensor and so forth, can be worked around (ie get the 24V sensors).

 

That might not be an issue, as the 53 is a STORM block, like that of the 24v's.

 

--------------------------------------------------------------------------
txrammer97:

I have a 1996 Dodge CTD 12 valve and when Scheid Diesel did my initial rebuild at 218,000 miles my original 12 valve block had "pinholes" between cylinder liner #3 and the outside area of the block, behind the inspection cover on the side of the block. Anyway, I went with a new Cummins 5.9 24 valve block and have had no problems whatsoever. I have been told that Cummins no longer builds a 12 valve block anymore. All they build now are the 24 valve blocks and the newer CR blocks. As the Members said one sure difference I know of is the extra hole for an oil drain built into the 24 valve block on the right (passenger side) of the that block.

Hope this helps you some.

--------
John_P

 

A 24 valve block is a 12 valve block, but not vice versa

A CR block is much better than the 24 valve block, but it requires custom fabrication to mount a p-pump.

 

The 24V block showed up before the 24V engine, late in the '97 model year, if that makes any sense. There were some differences. Here is some info on 24V block changes http://dodgeram.org/tech/dsl/mt_2_feb98/lower_end.htm

Picture of 12V block for comparison http://www.devilscastle.net/cummins_files/cumbay2.jpg

 

-------------------------------------------------------------------
Vaughn:

Thanks alot for posting that info!

--------
John_P

 

Thanks all fo the responses...Now lets talk connecting rods.... Are all 12 valve rods created equal??? Are 12 and 24 the same?

 

24Valve rods are said to be stronger.
Does the 24V block have any extra holes or ports for sensors that the 24V uses?
Just curious

 

I don't know so much about the rods but I thought 12V and 24V rods were the same. However the 3rd Gen ones were redesigned. Lots of debate as to which are better, supposedly the 3G rods are failing around 1200hp but maybe the 2G ones can take more. The 3G rods are narrower when viewed from the side, but thicker when viewed edge on. Plus they have cracked cap technology for more precise fit. Holding one of each in my hand the 3G rod looks higher quality, they weigh close to the same, but that's just my 2c. If I ever rebuild my 12V I'd probably put CR conrods in it.

Vaughn

 

Everything I read is the old rods are the stronger ones. The newer ones are powder metal forgings, which are apparently weaker. Just what I've read, I haven't broken any rods yet.

 

I was told several years ago that 24V rods were preferable.

When high HP CR engines started being built, the 24V rods were on of the first weak links. I think the builders are using CR rods in CR engines now.

When you have spent the money to make 1200 HP, what is a set of custom rods?

Since no one has a 1200 HP 24V VP pump engine, they have not hurt the rods yet.