Recent Topics
Synerlec and warranty
by jk_636
16 minutes 57 seconds ago
Where to buy Volvo S40 brake pads & rotors?
by Ed_Flecko
29 minutes 23 seconds ago
Why different starters?
by GreeCguy
46 minutes 25 seconds ago
Texas CHL holders
by aquariuscsm
Today at 02:31 PM
Chris King RingDrive substitute?
by nthach
Today at 12:08 PM
When to fill up?
by RamFan
Today at 11:46 AM
USPS tracking
by Dr_No
Today at 11:29 AM
2013 Grand Cherokee 5.7 Hemi OCI
by jeepman3071
Today at 10:50 AM
New to me 2008 Scion tC
by ThirdeYe
Today at 09:53 AM
Why Direct Injection Develop Carbon Deposits
by CELICA_XX
Today at 09:31 AM
Found a Repair Manual Site - LEGIT??
by SumpChump
Today at 09:30 AM
Drilling hole in front strut mount bigger.
by MobilinHyundia
Today at 09:28 AM
Newest Members
diematrix5000, sarswimmer1, oldmustangs, CristianJulio, 2010Forte
52674 Registered Users
Who's Online
99 registered (29662, 911Don, 1foxracing, 4wheeldog, 147_Grain, 7 invisible), 1738 Guests and 145 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
52674 Members
66 Forums
225779 Topics
3593331 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG
Page 2 of 2 < 1 2
Topic Options
#3066278 - 07/15/13 04:54 PM Re: Duece and a half [Re: ridgerunner]
2cool Offline


Registered: 07/13/11
Posts: 469
Loc: Delaware
The engines in the olde Truck, 2 1/2 ton, 6X6, M-48, were compression-ignition engines designed by M.A.N. (Machinen fabrik von Augusburg und Nuernberg) built under license for the Army by Mack, Continental, White, and Hercules. The pump was a Bosch single piston distributor type, where the fuel lines from the pump to the injectors looked for all the world like reallly long spark plug cables. As the fuel entered the pump, it went through the Fuel Density Compensator. The density of the fuel would cause an adjustment of the quantity of the fuel injected, and change the injection timing. The theory was that the denser the fuel, the more energy. The denser the fuel, the more time it would take to burn.

IIRC, the Technical Manual called for 1 Qt. SAE 10 oil per 10 gallons of gasoline, just to lube the pump. It would get much lower mileage on gas, but it would go. I believe that even with a turbo, the output was 130 hp. But then the Army only planned on it going 35 mph in line-haul style operations.

Top
#3358955 - 05/01/14 02:42 PM Re: Duece and a half [Re: ridgerunner]
ironman_gq Offline


Registered: 04/30/14
Posts: 147
Loc: MN
The old ones would run on just about anything because the injection systems were a lot more robust and simple. The old injectors were just a poppet valve with a nozzle on one side, it fired once per compression cycle and didn't need to be too terribly precise in metering fuel. Same with the pumps, they ran at a couple thousand psi at most, The new fuel systems on these trucks are using electronically fired injectors that can fire 4-5 times per cycle and pumps that operate at 30 thousand psi. To do that everything must have very precise tolerances, a change in fuel viscosity or a little debris in the fuel and the whole thing falls apart and parts get damaged.

Top
Page 2 of 2 < 1 2