Topping out at 62mph?

thats right barroll do not belive the brick theory get the bugs worked out the 903 were what they are but it will be ok

 

This is the kind of post I am sick of seeing. There is no helpfull info, no advice from experience, just another negative post that puts down the OP for no reason. I think barrol deserves better than this crap post. Barrol you are doing a hard thing buying and running that old truck but I think you deserve credit for giving it a go. I for one very nearly bought a k100 when I was truck shopping and I understand why you bought a truck like that. I am sure you didn't buy it just to be cool. Keep working at it and you will get her going good in the end, as for the crap above just ignore these types of posts as they aren't worth worrying over!

 

The hyper mile types around here say you can drive any speed you want. Might want to stay in the right lane though.
Try not splitting your down shifts. Go from 8th to 7th leave the splitter alone. I only split down shifts when I know the 1 split will crest the grade I'm on.
That's a cool ride enjoy it!

 

Did you get your tractor straightened out?I think the 903 would turn 2750 rpm from the factory as I recall I have been thinking about this for a couple days now.I still run a cabover myself, it is a 1994 frieghtliner with a 3406C PEEC engine( these are the engiines I was told that are no good. Mine has been very good although a mechanical 3406C will walk all over mine.It averages 6mpg over a years time. 10 speed overdrive transmission and 3.91 rears with 11X22.5 tires.I pull a flatbed myself and haul steel so heavy most of the time. I did not mean to impune you when I asked if you got that tractor to be cool (they are already cool. The 903 was what I was talking about,and as far as going to a KW dealer that can eat you alive, according to your reply you did what you had to do. Good for you keep it up.Anyway you might try running that up to about 2300 or 2400 and the go for your next gear I would split on the upshift and not split on the downshift Maybe downshift up around 2100 or 2200 and see what happens. these are old engines and you have to run them different than the ones we have today. maybe try the fass system (which I have on mine ) and see if that helps. It would be great if you could get 5.5 mpg out of that thing and I hope you can. PS I applaude you and think your tractor is cool. I am hopeing we can become friends and exchange stories and ideas. Keerping the dream alive.

 

Well, got the truck out of the shop. They adjusted the throttle rod (I thought I got it all the way out, but after looking at what they did, I was about an inch and a half short of full travel), noted the turbo was running at 30% boost, and that one cylinder is missing. They also pressure tested the fuel system and found nothing out of the ordinary.

I told them to stop right there, and it only ran me $200, but they said identifying and diagnosing the miss would likely be a 6 hour job before they even did anything about it.

Took it out on the big road, and guess what? Ran 66mph all the way home, 11 hours straight.

Tried downshifting at 1900rpms, and that kept the shifter up against the hard rail all day. Only saw 6th gear going down the road because I missed a downshift going uphill. No more lugging for miles, no more sluggish acceleration, and I got to see the left lane hopping around governed trucks a couple dozen times.

I've been splitting the downshifts, since if I go from 8 direct at 1900 to 7 direct, it puts it up around 2400rpm, which is a bit higher than I like to run it, and 7OD puts it right around 2200, which it will usually hold over mole hills.

My upshifts are at 1600 in low, and 1700 in direct until 7th gear, and I wait until 2000 to hit 8th, then 2200 to get to 8OD. It might not be the fastest way to top gear, but I don't really need to run my 4 ways to do it either.

I was an engineering major my first two years of college, so I don't give any creedence to the brick theory. Unless we're talking about a wedge, a hood is only going to add surface area, which is going to add drag. I wanted so badly to get a peterbilt 372 for their aerodynamics, but I couldn't find one when I needed it, so a split screen K100 is the closest I could get to a wedge. I'm going to do a bit of aerodynamic work on it once I get done with the mechanical and electrical.

I haven't run the numbers for my fuel economy yet, but I'm running the tanks low now that I can shut it off and let them level out, so I can mark off my fuel stick and get some more real time numbers than just comparing my fuel tickets to my log book week to week.

 

glad to hear all that something else you might want to try is putting walmart 2 cycle outboard motor oil in your fuel to help keep the injectors lubed up. The fuel we run today does not have much lube in it and our old engines were not designed to run on it.Split a gallon between each tank about once a week when fueling

 

I'll probably try running the two stroke oil for a few weeks and see how it does.

Something seems to be getting pretty coked up idling overnight, so I usually leave a giant white/gray smoke plume on the first onramp I hit every morning, then its just negligible puffs of light black/white smoke throught the day approaching WOT. Wouldn't be surprised if it was the injector spray pattern getting a bit wonky at those lower speeds for so long, especially with a misfiring cylinder. While an Italian tune up corrects the problem for a day, my long term solution will be a proper APU, since idling seems to be nothing but trouble for the bottom end of these engines.

Also, planning on a full fuel system rebuild down the road so I can run B100 biodiesel. I've never wanted for lubricity running B100 in sub 200HP engines, and a properly set up B100 fuel system cleans and lubricates itself better than any additive has in my experience. Running B100 in one OM617 corrected issues with pop testing I was afraid I'd need to replace the entire set of injectors over. New nozzles helped a bit, but a month running B100 got them all back within spec.