Cat 3126E as exchange for 8V-71?

bevans6 · November 18, 2009, 07:00:51 AM

Just blue sky wondering here, would a Cat 3126E be a viable exchange option for an 8V-71? It appears to be smaller in all dimensions, including length which is important in a MC-5C, it has similar or higher RPM requirements so you wouldn't have to re-gear, and it has power up to 330 hp, so you could get similar to the 270 hp of the stock 8V-71 or up to 50 odd more HP. I have never heard this option discussed before... Any thoughts?

http://www.catpower.co.nz/Site/Files/a/06cc20404d351cbaa2520fcd0d5adc3/cc7a5d2c695fd0b8c732ea79642ac04f/3126E.pdf

Brian

luvrbus · November 18, 2009, 07:27:16 AM

Brian, the 3100 series are the worst Cat engine built I put them in the same class as a 3208

good luck

usbusin · November 18, 2009, 08:17:37 AM

luvrbus said;
"the 3100 series are the worst Cat engine built "

Wow! I sure hope you are wrong, luvrbus. I have a 3126b (300 hp/860 lb.-ft torque) with 112,000 miles; going strong and no problems.

What should I look for before it fails?

luvrbus · November 18, 2009, 08:24:26 AM

Gary, you don't have the E those burn pistons and have head problems.

good luck

usbusin · November 18, 2009, 08:27:01 AM

Thanks, luvrbus, you had me scared and wondering!

Is the E the same as the C7? I take it, it is a different design than the B?

Don Fairchild · November 18, 2009, 08:55:06 AM

The C-7 is a redesigned 3126 and is not a bad engine for it's size, but the 3116 and 3126 have had a ton of problems. They are thought of as throw a way's when problems strike.

Don

TomC · November 18, 2009, 09:06:08 AM

We put lots of 3126b's, E's and C7's in Freightliner trucks. While the B's were fairly reliable, they all seem to suffer from eventual injector pump failure. The electronic injectors work by pumping up the engine oil to a few thousand pounds of pressure to power the individual injectors. The high pressure pump has a tendency to not last much more then 100,000 miles. And since the injectors are double wammy's (meaning the high pressure oil is at the top of the injector pushing the piston down to push the fuel in), they are expensive. The good thing is that the engine is about 1,000lbs lighter then the 8V-71, but you have to install an air to air intercooler.
Personally- if I were to select a medium sized engine to replace the 8V-71 and this came up to replace my 3406B Caterpillar in my truck because of smog-until finding out that RV's are exempt- I would choose the Cummins ISL 8.9 liter since you can get an RV rating at 400hp and 1200lb/ft torque. The ISL is also about 800lbs lighter then the 8V-71, has wet cylinder liners, 4 valves per cylinder and now has common rail fuel injection for quiet operation. The main reason to choose the Cummins over the Caterpillar-mainly Caterpillar is out of the truck and bus market-although they are continue making the engines for other markets. Cummins, on the other hand, is going to continue to make the ISB, ISC, ISL, ISX in both 11.9 and 15 liter engines into the future. The only engine that Cummins is cancelling is the ISM, with the ISX being modified from a dual overhead cam to a single overhead cam. Good Luck, TomC

luvrbus · November 18, 2009, 09:14:43 AM

Your cold DON I wasn't going to tell Gary about the problems .
My guys at Cat tell me that Cat and Navistar Truck has taken that engine along with others and some Navistar truck engines and opening a plant in China and are going to change most of the truck engines to a V design.

good luck

TomC · November 18, 2009, 09:21:15 AM

Luvrbus- currently- the only engine that Caterpillar and Navistar are using is the C15. Navistar otherwise is still using their 7.3 liter, DT466, DT530, Maxxforce 11 and 13 liter (MAN engines). No big engines are going to be created in V designs.
I did talk to Cummins factory reps last week, and they are coming out with a 5 liter V-8 and a 3.8 Liter V-6 Diesel for pickup and smaller SUV's! I'm excited about that. In the coming years, you're going to see alot of new Diesel engines for all applications-you can't beat the economy of a Diesel. Good Luck, TomC

usbusin · November 18, 2009, 02:17:19 PM

Injector Pump failures on the 3126b.

At 112,000 miles what should I look out for? Is it a catastrophic failure? Will it leave me stranded on the road? Does it go into "reduced power" mode? What is the cost of the pump?

I thought I had a 500,000 mile engine or so I was told. Now you guys have me nervous.

luvrbus · November 18, 2009, 02:25:14 PM

TomC fwiw Navistar and Cat have a joint venture in engine manufacturing in China I am going there next spring with a friend of mine to the plant.

good luck

Don Fairchild · November 18, 2009, 02:33:26 PM

Clifford; Wasn't trying to be cold sorry.LOL

Don

DaveG · November 18, 2009, 08:12:00 PM

You all know that Cat and Navistar are jointly building a truck...right? That's were the C-15 come into play. Supposedly it is going to be call the Cat Truck...just what I heard.

TomC · November 18, 2009, 11:50:41 PM

USBusin- there is no real warning that the high pressure fuel pump fails. Is it a catastrophic failure-not really. Will it leave you stranded on the side of the road-yes-you'll have to get towed. Does it go into "reduced power" mode-not usually-it just quits, or you can't get it started. I believe the pump is around the $2,000.00 mark-with labor. Yes you do have a 500,000 mile engine as far as the block, pistons, connecting rods, valves, etc. Just the high pressure fuel pump is a Achilles heal. Good Luck, TomC