Cat 3126 or Detroit 50

ds1450 · Mar 12, 2009

I am looking at a couple of older trucks. One is a 2000 FL 80 with a 3126 Cat @ 600K. Well maintained, no blow by, doesn't burn oil never a problem. Diagnostics and compression check all good.

The second is a 2001 FL106 with The Detroit 50 engine and 450K. Well Maintained (this one sounds real good too) Same as above. Probably a bit better maintained.

The question. Which one will last longer and what problems can I expect with either?

Which has a better track record. I know the Cat is pretty much a throw away engine when it does go. I don't know a lot about Detroit Diesel

Your thoughts please.

truckrnnr · Mar 12, 2009

I own a 2000 FL-106 with the series 50 detroit. I currently have 778,000 on it and it runs like a champ. The power is better, the milage is better. ( I have a 9 speed and get 12.4 MPG loaded at gross (33,000) running 63 mph) I have never gotten lower than 10.5 MPG, but that was running in the mountains and rolling along at much higher speeds.
The Detroit series 50 is actually a series 60 (12.7 liter) with 2 cylinders chopped off. The engines are known to get 1.5 million before needing rebuilt.
The only thing under my hood that ever gave me a problem was an alternator.
I would go for the detroit,.......but before you buy it,let me tell you this,..... If it has the non syncronized 9 speed tranny, they are a pain in the *** to get used to. On the low side, you have to wind it ALL the way up, and it will lose ground speed fast so you have to be quick getting the next gear, this is especially an issue when loaded and pulling out on a grade. You'll not even notice it after a while. Test drive the truck, and pull out on a grade and you'll see what I mean. It also takes the turbo a little while to spool up (everyone i ever talked to that had this motor tranny combo said the same thing) GOOD LUCK. P.S. I will sell you mine if you're interested.

davekc · Mar 12, 2009

Based on the milage and the other truck a year newer, and assuming the same price, I would take the Detroit.
The Cat 3126 is a great engine as we ran one up to 800 plus before selling it, and it is still running. Not sure of the current milage but I would have to think 900 or better. Only repair was a oil pump seal, and a blown water pump. Not bad against that milage. Detroits are major oil leakers, but they are economical to rebuild. Can rebuild a Cat as well, but you like will lose some displacement as they have to be sleeved. Also have to make sure there is no block damage.

ds1450 · Mar 12, 2009

Thanks Dave... Looks like I found a pretty good truck. I'll let you know how things work out as we are still talking.

truckrnnr · Mar 13, 2009

Something else to consider with the FL-106 is the truck weight. mine has the series 50, a 9 speed,72" alumabunk sleeper,24" box and dual 75 gallon tanks. With a full load of fuel and no freight, the truck weighs in at 21,600 lbs. (this is with all my stuff inside,and me) not much cargo capacity if it's a single axle 33,000 GVW. Does the truck have an air tag axle???

greg334 · Mar 13, 2009

Always select the wet sleeve engine over the dry sleeve engine. The quality of the rebuild may be a bit better with the wet sleeve engine because the cylinder and piston can be replaced in frame, where the dry sleeve engine may have to be pulled out depending on the experience of the rebuilder.

3126 parts seem to be getting expensive but I see DD50 parts holding their prices.

guido4475 · Mar 13, 2009

can anyone tell me what is the best tire for my cargo van? brand,treadpattern, etc.where is the best to purchase them? i imagine 10-ply is the best way to go.

ds1450 · Mar 13, 2009

Hi Guido...

please post a seperate thread for tire talk. This is Engine talk. Looks like the Detroit is the winner... sounds like a pretty stout motor.

Thanks.

guido4475 · Mar 13, 2009

i was trying to figure out how to change the tread to just that, but it is obvious that i was unsuccessful in doing that.sorry to interrupt your conversation about engines.