which engine will have more torque, the 350hp M11 or the 355hp C12? how far can they be turned up? which engine is better? any info is appreciated, thanx. Casey

 

In marine trim, the M11 goes to 705hp. The Kat C12 acert goes to 715hp. I think the Cummins has the advantage in this engine size. Either one will have around 1450 for torque

 

My experience is on-highway. It was accepted for decades that CAT was the Rolls Royce of heavy diesel. Since the Series 60 is not on the table with its 1,000,000 mile design life, I would still have to say that the CAT is the better engine.

You did not specify stock engine rating increase or juice it up. With CAT's I had a friend with a 3406(C or E - don't remember). I was at Rush Peterbilt and I heard a truck on the dyno and went over to get a look. It was a friends tractor. He was retiring and placed it for consignment sale. Rush was cutting it back to stock. I saw the reading of 510 HP to the ground and it had a lot left. The mechanic stopped the test because that meant the engine was near 600 Flywheel HP with some left. So he knew what he had to do.

One year at Dyno Days in San Diego a 3408 CAT that had been stock at 450 HP won with a reading of 1,000 HP to the ground! I believe on average CAT's have greater power potential. I have also seen a lot of CAT's go over 700,000 miles. I have not seen that from Cummins.

One of the biggest reasons behind Cummins popularity in the past was cost. They were cheaper to maintain. I replaced a water pump on a Cummins at the same time a friend replaced a water pump on a 1693TA. My pump cost $100 while his cost $1200. We both did our own work. It took CAT almost a decade and a half to implement changes that have significantly reduced the cost of owning a CAT. As a result CAT has gained a big chunk of Cummins former market share.

 

With your particular question- Cat,hands down. The cummins m-11 while used still today by many companys w/older equipment was a terrible and unreliable design. the c-12 from cat is based on the proven 3176 engine platform and is very reliable and a good engine for meduim to light/heavy duty(light/heavy would be a single axle day cab tractor, or city truck) I've seen over a million miles on both designs with no major malfunctions but the cat will make a mill. with less maintanence. In the heavy and med. feilds the best cummins has to offer hasn't been offered in years- the n-14,855 big-cam turbo, and, IMPO, the best engine ole' cummapart ever made(excluding the B and C series) The L-10. The m-11 was supposed to be an upstep from the L-10 but the design changes weren't good. The m-11 brought electronics along w/other changes. We've got an L-10 in an '86 pete 379 tandem dump truck with 1.43 million miles on it and it's never been inframed. That's a good engine!!! The two cat's that we had,1-3176(800,000) and 1-c-12(650,000), were sold last year both still kickin with nothing more than PM done to both. There still haulin in East AL w/no major work yet.

If your lookin for a truck, I don't recommend either engine, go bigger you won't regret it. Older ddc-3 or 4,Cat-3406C or E or c-15, Cummins-N-14.Every engine here is proven and will do the job(the cats are the user friendliest if you do your own maintanence). What ever you do stay away from anything with egr or emmissions control on it.The only one I'd be willing to try is the new cat acert system but that would entail a brand new truck(with a brand new payment).

 

I vote CAT! Worked on both for an OTR company the Cummins were more like the old AMF Harley Davidsons. "Drive a little wrench a little drive a little more wrench a lot". The CAT always seemed smoother we were running at the time 3406A,B,C,E vs the Big Cam IV. The cement mixers we had were powered with the M11 better known as the "M---a-Lemon"

 

The "M-A-LEMON" So true!!!

 

I worked at a Kenworth/Volvo dealer for several years and I am going to say take the M-11 if it is a Plus with a 6662 ECM. The Celect Plus had better ECM wiring. The sensors on the motor had their own wiring circuits. The first Celects didn't. The C-12's were a big improvment over the 3176's which should have been painted green and I liked them because they made me alot of money. Yeh there were several that had alot of miles on them but you could hear one for 10 miles when the compressor was pumping air and I did alot of head gaskets because of the aluminum spacer block and injectors sleeves and not to mention all the timing gear covers that broke at the alternator mount area. Pretty bad when I had a box full of magnets to hold the cam followers up so I could get the cam out without pulling the head to get the cam follower assemblies.

As far as big motors, take the N-14. They had very few "problems" that I saw over the years. Had to in-frame very few. They liked injectors and they needed to be re-programmed every now and then but I worked alot more Cats. If you get a 3406 get an old 7FB motor. The 4CK's , which could have been a B or C engine depending on the serial number, weren't to bad at all either once you re-did the transducer and put the oil pressure sensor were it belonged. The "E"s were ok but they could still cost you alot of money.

The Detroit 60's DDEC 3 were an awsome motor. Besides the piston ear failures that went around in the late 90's and a few soft cam issues they had which Cat did too.

They all have they own little things about them.

 

Thanx for the info guys, we ended up buying a '97 Frieghtliner Fld 120 daycab with an N14 and 10 speed. Its got close to 650,000 on er and she still runs great. These daycab trucks are hard to find around here with big engines. Found a lot with pos M11. My dad would have gone for one of those if I didnt complain about lack of horsepower. I wish it would have had a jake but its better than nothin I guess. I love that jake on our other truck, Its a '90 8300 Intl with a 855 bc 3 in it. I put a different button in the pump and put two 6" curved chrome straight pipes on it. I LOVE the way she sounds!! Especially when I hit the jake. Mighty fine noise!