The Combine Forum banner

903 cummins

7K views 14 replies 10 participants last post by  CRToney 
#1 ·
what is the proper way to remove the rear crank flange on a 903 cummins? remember doing one with the engine still in the tractor and it was a *****. this time the engine is sitting on the shop floor so looks real easy.you can't push it off so is a slide hammer my best bet?
 
#2 ·
I had to change the rear crankshaft seal on my 4880 massey. I made a "T" puller and used a pipe wrench. I put the pipe wrench on the front dampner pulley and let it hit the frame of the tractor, this held the crank still while I used the T puller to remove the flange. I think you would have a heck of a time removing it with a slid hammer, even if it is out of the tractor.
 
#7 ·
there's only three of us left in the world running the 903's so we are badly out numbered, but you either love them or hate them. could be a long cold winter so lets compare them to the straight six. I will sit back and read the pages and pages of experts.HA HA I got nothing better to do.
 
#9 ·
903s were a decent engine that saw a lot of marine duty and some fire engine use, they ran at higher rpms than the 855, and when they fell off the torque band it was quick. some how the 855 seemed to be a better ag use and truck engine , and the rpm band was aligned with the transmissions offered for them as well as other brands. the one issue with 903s is the v of the block was hard to keep clean and the fact that the injection pump was not as easily accessed. i had a friend who washed his v out, and promptly bent a connecting rod, due to the fact that however had installed the intake gasket did not align it and therefore a crack was open to the atmosphere. it never dusted the engine due to the positive intake pressure from the turbo, but when the water filled in the v it ran into the intake and cylinder, ouch, i fixed it and luckily it is ok now, but about 1500 bucks for parts and labor
 
#11 · (Edited)
I bet in boats they could easily go far beyond 450hp remember water from sea is essentially unlimited cooling i find it interesting you think the 855s ran better in ag applications than trucks in trucks they seem to last forever and ever in ag situations they never seemed to surpass 10,000 hrs. I have seen literally dozens of 9000series ford and nh 4wd s amd case 9000 series 4wd s with rebuilt engines or new engines in the 4-7000 hr range yet in big truxks the N14 s would easily make 20,000 hrs i figured the higher load cycle of ag wore the wngine out prematurely my N14) in my KW is almost at 26,000 hrs internals all original
 
#13 ·
next question, is the camshaft in a 4900 engine that much different then one in a 4800? tore a 4800 engine down,broken sleeve. everything looks good so will rebuild it just because. I have access to 4880 and 4900 parts, and an engine kit is 2700$. they run different injectors and pump numbers but pistons are all the same. simple engine to work on. 60 series detroit would be my choice but frame welding and other changes are a big job.
 
#14 ·
" 60 series detroit would be my choice but frame welding and other changes are a big job. "

Definitely was a lot of hours involved in installing a 6 cylinder engine. For the cat engine We had to Stretch the frame and manufacture motor mounts. Plus all the gauges and such takes time. And just because its awesome we even hooked up the jake brakes to a switch in the cab. Ha. Spent most of a winter tinkering with it.
 
#15 ·
Not a fan of any V8 diesel. 5 mains on a V8, 7 on a I6. Short stroke engines don't develop the torque of a long stroke I6. I6 is simpler and easier to work on. HP = torque x rpm/5252. To get the same hp a lower torque engine needs to spin faster. Lower rpm usually equates to better fuel efficiency. A good read is "The Diesel Odyssey of Clessie Cummins" by his son Lyle. After Clessie was no longer working at Cummins they developed the 903 and the 555. Being a practical guy with lots of trial and error experience he wasn't in favour of their development. The best story from the book was the near death experience that lead Clessie to start development of the Diesel engine brake.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top