Mil. surplus 6.2 diesels

In regard to the thicker blocks - it had nothing to do with military use. Around 92 and 93 - the same block was being used for the 6.2s and 6.5s - and it was cast thicker - civilian or military. That's when the 14022660 block (1982-1991) was dropped, and the thicker 10149599 block was used in both the 6.2s and 6.5s. The new block also uses a new crankshaft with a one-piece rear main seal. After the #599 block was changed again - to 12552929, 10237141, and 12555506 - it was cast thinner - in all applications. The new 6.5 blocks - being made now - for anybody who has the money - e.g. marine use, military Humvee, etc. - are the thickest and also have the highest nickel content. Also, the main-cap bolts are different to prevent block-cracking at the main-bearing webs. These new blocks are being cast by Remy-International - same company that casts the Ford-Navistar diesel blocks. Also, with the military 6.2s - they were not detuned. They had the fuel delivery rates turned up a little higher than civilian models - and rated torque and horsepower were exactly the same as the J-code civilian 6.2s. But, the military used a lot of 6.5 blocks to replace 6.2s - and those 6.5s were considered "detuned" to match the characteristics of the 6.2s they were replacing. Again - in regard to many failing a 1000 miles - it has a lot to do with the extreme overload caused by the armour added - and being driven in high heat and sandy conditions. Number one failure issue was - and still is - the Stanadyne injection pumps.

" . . With the recent major combat operations in Afghanistan and Iraq, fuel-related problems have
increased significantly as a result of using low-viscosity fuels as the single fuel. In Afghanistan,
much of the aviation kerosene that initially was procured was Russian TS1 aviation kerosene
because the neighboring refineries produce aviation kerosene as TS1 instead of Jet A1 or JP8.
The Russian TS1 aviation kerosene is similar to Jet A1, but it is more volatile because it has a
lower flash point and a lower viscosity.
The fuel being used in Iraq is JP8. However, in both Afghanistan and Iraq, the ground vehicles
and equipment are being used much more extensively than they would be used in normal
service. Considering this added use, the hot temperatures that typically prevail in the Middle
East, and the increasing engine-power demands imposed by the increased weights of up-armor
kits, it is no wonder that the ground vehicles and equipment that have rotary-distribution,
fuel-injection pumps have had many fuel-related engine problems. "

And another:

" July 2004 issue of National Defense magazine, Army Ponders New Diesel Engine for Humvee
Trucks," notes that maintenance nightmares have been experienced in Iraq because engines
regularly break down and often must be replaced after only 1,000 to 2,000 miles of operation.
Much of the blame for this is placed on the bolted-on armor protection that adds weight to the
vehicles. However, the inability of the rotary-distribution, fuel-injection pumps to operate
satisfactorily for sustained periods of heavy-duty operation is probably a contributing factor,
especially when low-viscosity fuel is used in a hot environment. Interestingly, the fuel-injection
pumps in many, if not all, of the HMMWVs operating in Southwest Asia have been retrofitted
with Stanadyne's Arctic Fuel Conversion Retrofit Kit. This kit apparently has done little to offset
the significant increases in maintenance that have been experienced recently. Combat operations that occur in higher temperature environments certainly will intensify the
operational and maintenance problems of diesel-powered vehicles and equipment with
fuel-lubricated fuel-injection pumps. Since almost half of the Army's diesel vehicles and
equipment have rotary-distribution, fuel-injection pumps, a solution is urgently needed. "

We went thru lots of the injection pumps and had several times that vehicles were out of commission as there were no new pumps to be had for our maintenance folks.