I have a few question for you guys. I purchased a used Dump truck yesterday. 1984 Ford LN7000. I was told it had a 3114 Cat re-manufactured engine. I paid $2900 which seemed reasonable.He wanted $4200. Did I get a good deal? when I got the oil cleaned off the sticker said Cat Re-manufactured 3208. I Feel like I was lied too. I am looking for a service manual and the number I found stamped on the valve cover is 9L7429. Do you know what service manual I need? Just curious which motor is better 3114 or 3208? I read negative about both. 328,000 miles on truck odometer. Service meter reads 1839. It has a new battery, 4 new rear tired and a new muffler. Small leak out of PTO. I am new to the dump truck world, just doing some work at my acreage. Thanks in advance, Tim
3114 is a straight four and 3208 is a V eight so you should be able to tell which you have easily, but going from your part number of 9L7429 I can tell you have a 3208. I have little experience with either of them in on highway applications, but not many other people have much good to say about the 3208. In industrial/offroad applications I have found them both to be fine within their limits given proper care.
Cmark has it right about proper care but then that applies to any truck/engine. I've driven an 8 yd dump with the 3208 and it's a tad underpowered in hilly country with a full load. It's not a heavy duty type engine but in a 5 yd dump, should be fine as long as you stay within it's limitations. Best power range I'd found was to keep it between 1500 and 2000 rpms, shifting as needed.
the 3114 wouldn't be found in a truck like that. The 3116 came out in top kick gmc trucks about 1988. The 3114 would be too small . The 3208 can be a good engine if tuned right and taken care of. They started good and pulled pretty good too. I would recommend a valve adjustment periodically which will catch failing valves seats and guides which seemed to be a common failure. You will probably have better luck with the 3208 then you would with a 3116/3114 . There are less fuel system parts and adjustments.
One thing to watch on the 3208 is overspeed going downhill. They're a short stroke V8 so they don't have much compression, not that any diesel does, so it's easy to exceed the redline on the tach coming off a hill with a load on.
Thanks for all the information. Any idea what service manual I would need? I will be doing general maintenance. Cat 3208 with 9L7429 stamped in the valve cover.