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Caterpillar 3126

176K views 20 replies 14 participants last post by  quigley73colo 
#1 ·
I was looking at some of the class 6 trucks and noticed that the Caterpillar 3126 engine was listed in several trucks. Each had a diferent horsepower and torque figure listed. One was 275 and I think 750 ft. lbs. torque. Another 300 hp and 800 ft/ lbs. torque. Still another was 330 hp..

Are all of them the same engine with diff. pumps, injectors and turbo's or what?????
I assume they are all mechanical injection. As such gaining hp would not be as easy as with my Powerstroke by just changing the computer programming.

And could you take say a 275 hp version and make the changes to bump it up??? And how far could you bump it without shortning the life of the engine?????


Just doin some lookin and research for when I go to replace "Little Red".
 
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#2 ·
Hopefully this'll help ya, im goin to guess these 3126's are in 99-00-01 trucks which those are electronic fuel injection, CAT uses the Huei fuel system on those engines which you can "bump" them up.. some of which can be done with the computer but there are certain specs where you have to change the pistons maybe turbo or injectors.. best bet would be to call a cat dealer to find out what ur lookin at! also www.cat.com might give you some additional info!
 
#3 ·
i have a 3126 in a 2000 f650,the info i have is a fax i got from cat,it shows all the 3126 engines from 170 to 330 hp,the diff.are injectors,turbo housings,fan pulleys,nothing said about pistons.warnings about rad. size and intercooler size if going up to 300 from 170/190...the 330 is a rv/emergency vehical option.i think you could talk your cat guy into giving you the 330hp!problem is that to upgrade to higher hp there is a 750 dollar charge for the computer work,if your unit is still under warrenty,if out of warrenty its an hour of shop time,$50 at my local cat house..plus the injectors,plus the turbo housings.the pulleys are a judgement call,they just speed up the water pump to push more water for better cooling..3000 dollars to update mine to 300hp..i'm gonna wait till its out of warrenty to do it!!save 700 bucks!mine pulls very well and its a 190hp .the problem with these trucks is the rear end ratio,the highest that ford offers is a 3.91.you can get a 3.73 from rockwell,which is what i did,i changed from a 4.11.it was a good change but was still too slow,75 mph @2500rpm..the thing would pull like mad till 2200 then it was sit back and wait,so i put a aux.3 speed with overdrive in it,now 75 @2000!you can idle along @1500 no problem.now i need to recalibrate the speedo...
 
#4 ·
Someone correct me if im wrong but i read where the 3126Cat @ 330 h.p. is mainly for fire/rescue & ambulance use only .


I have several friends who own 3116 & 3126 Cat motors both & the most hp ive seen in a "cilvilan" truck was 300hp

Yall have a goodone


B-61
 
#5 ·
Thanks guys! That is the information I was looking for.


And I should have guessed that just about everything is computer controlled by now.


Actually the one I am most interested has the 300 hp 800 ft/lbs. torque. with the Allison six speed behind it and 4.88 gears. So it sounds like it is about at the top of the heap....... But maybe a LITTLE room to play.


Now all I have to do is scrimp and save. This so I will be able to go for it when the time comes to replace "Little Red".


Thanks again!!!
 
#6 ·
I own a renegade/freightliner with the 330hp restricted RV rating.
It is for RV/fire and emergency use only...
I have talked with other owners as low as 250hp that have upgraded to the 330hp spec. It pays to find a good service tech!!
 
#7 ·
hello.

i was looking at a 650 SuperCrewzer a couple of days ago. it had a Cat 3126. the sticker said 300/800. the sticker also said $93,000.00+. i kind of forgot the small change in my 'sticker shock'.

it was a really nice truck and i liked the way it drove. the Mrs. and i are gonna be done raising kids in a year or two and have plans to be effectively homeless, or at least to carry home with us.

i have looked at some of the Freightliner and International trucks that were similar and they are all nice.

while i doubt that i am gonna do anything about this very soon, it sure is nice to dream some.

anyone who has any input on this would be welcome to contribute. what we are looking to do is pull a 5'er and do lots of miles. we have kids scattered all across the country and would be visiting them and 'just traveling'.

thanks.
bill
 
#8 ·
The supercrewzer is RIDICOULSLY overpriced!!


Have you done much research yet??
Check out www.crewchief.com they start at $75,000 and offer a heck of alot more truck.
 
#9 ·
P.S.


The "AERO-CONDO" is one slick little unit!!
 
#10 ·
Salvage1;
The way I got around the 75 mph limit was I ordered an allison auto as a 5 speed. Seems they deliver a 6 speed w/ the 6th gear programmed out. When it arrived even before I put on the box, I took it to an allison service center and had them program it to a 6 speed. It cost me around $600 bucks to do the reprogram. Now I can't take credit for this clever approach, I had an excellent salesman who knew trucks!

Now I didn't want a truck that would run faster than 75 mph, but I did want to run it around 70mph w/o it being up against the governor. That was my reasoning for the increased limit. When I ordered mine they limited top speed by gearing and governed speed of the engine. I geared the truck to run at 82MPH, at 70 is is very comfortable (In IdeeHoe we can legally run 75!).

Anyway, there are always ways to skin that Cat!!
 
#11 ·
my truck had no speed limit programed in,it simply ran out of motor,too low of a gear,i have the 4 speed allison,no overdrive in it..when you buy used,you get what you get!
 
#12 ·
I don't know if CAT changed it's ratings, but my 97' FL60 has a 3126 w/ 275HP & 860FT.lbs. According to the CAT info I have, the 300 & 330HP remain at 860ft.lbs. The numbers you guys are talking about are lower torque ratings for these models. Also the 3126's w/175-230HP have different pistons from the factory than the models w/ higher HP. I wouldn't recommend bumping those lower HP models up to 250HP or more. The stock pistons are probably not designed for the higher HP. I would also look into what HP is the most efficient for your application. I tow a 13,000lb. 5th wheel camper on open highway. I've found that running about 1800rpm(63-65mph)is the most efficient for traveling. If I bump it up to 300 or 330HP, the motor may burn(waist) more fuel than needed for the job of pulling such a light trailer for the truck, without any increase in torque. I could be wrong, it's just a theory.

I do have a question about the 3126 though! Does anybody know at what pressure my waistgate is opening on the 275 HP model? I'd like to buy a boost & pyro gauge and mount them to the dash. I just don't know how high of a boost gauge to purchase!
Thanks.
 
#14 ·
HP and torque often confuse folks. I will try to describe one way to look at all this; torque is the force that moves you up the hills and down the road. If you remember someone in physics stating that Force equals Mass times Accelleration. Torque is the force part of this equation, it is what moves you.

It is the most important spec when looking at any engine for that matter. For some reason manufacturers always focus on HP, when in fact torque is what makes things move. HP is related to RPM, there is a formula that is: HP ~ torque x RPM (with some other factors thrown in). You can take an 860 ft-lbs motor and through changing the fuel curve have the peak torque hit at different RPM's. That is why you have 330/300 & 275 HP engines w/ 860 ft-lbs of torque. The 300/330 HP engines have the torque curve moved to the right slightly, thats all.

So if you are looking to tow weight up a steep grade, torque is what does the work. You should gear the vehicle to have the torque where you need it most, at the RPM you typically pull. Otherwise you really don't care about the HP factors. If in doubt, take higher torque over HP any day.

Hope that helps...
 
#15 ·
<blockquote><font class="small">In reply to:</font><hr>

hello.

i was looking at a 650 SuperCrewzer a couple of days ago. it had a Cat 3126. the sticker said 300/800. the sticker also said $93,000.00+. i kind of forgot the small change in my 'sticker shock'.

it was a really nice truck and i liked the way it drove. the Mrs. and i are gonna be done raising kids in a year or two and have plans to be effectively homeless, or at least to carry home with us.

i have looked at some of the Freightliner and International trucks that were similar and they are all nice.

while i doubt that i am gonna do anything about this very soon, it sure is nice to dream some.

anyone who has any input on this would be welcome to contribute. what we are looking to do is pull a 5'er and do lots of miles. we have kids scattered all across the country and would be visiting them and 'just traveling'.

thanks.
bill

<hr></blockquote>

Bill,

Keep me in mind when you get ready /ubbthreads/images/icons/wink.gif

Thanks,
 
#16 ·
Has anyone had valvetrain FAILURE on a 3100 series motor??
Check out the thread in general diesel......
I have lost my faith in CAT for now, I hope my motor is repaired with UPDATED parts that fix this problem!!
 
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