mhuppertz

Anyone know if Cummins used a larger rotary style pump on the bigger sixes?

JQmile

Yup. Back when Diesel Power Mag was at the Wilshire Blvd address, the backup generator for the building was an 1150 cid KTTA Cummins. Had a big rotary pump. Won't work on a 6bt or so I was told after I saw it and asked a few people

pulltilbroke

A lot of people say we can't make any power with a VE also, I'm sure there is a way to make one work.

mhuppertz

How is your 14mm pump holding up? Are you going to run against the 2x4 Ford in the mag?

JQmile

It's holding up fine...I have about 600 miles on it and 10 dyno pulls....still doing great, although I think a lot of that has to do with having a 3200 spring and 30 psi of inlet pressure.

mhuppertz

Have you run it down the 1/4 mile yet?

What are your best dyno numbers?

dzl_damon

exactly. They can put a P pump in a powerstroke, I'm sure someone could get that larger rotary pump to work in a B series.

kensmachine

The pump on the KTA and NTC engines is not a rotary pump the system is called P/T = Pressure Timed all the pump dose is supply pressure to the injectors and the cam activates the injectors its nick name was Part/Time ken

wannadiesel

Yup. We cant use it for the same reason we can't put a "real" jake brake on the 5.9 - no injector lobes on the cam.

dzl_damon

Gotcha... unit injector set up I guess?

pwrtripls1

Exactly, I've got 3 KTA50 Cummins GenSets with 1050kw 600v gens and they are the hardest things to tune. I run them all with Woodward 2301D governors and trying to build the program to run those pressure timed pumps is a headache. I finaly have a generic tune I load and tweek from there, but I'd much rather have a 3506 Cat in there place. The Cats respond to load instantly and have way less problems than the Cummins crap we bought. I'm sure in a supply boat they are fine, but on an oil rig as a genset they seem to suck!

mhuppertz

Are those big V8's? Too bad they are giving you problems. We found the CAT motors were loose and ate a lot of oil and parts in backhoe's. The Cumminds motors always outlasted the booms.

pwrtripls1

They are 50Liter V-12's designed for boats where the engine load is fairly steady, not for gensets where the load comes and goes really fast. Its like trying to drive a tanker in stop and go traffic.

The Cats we use mostly are 3512's, which are V-12's, but we do have 2 3508's and they have plenty of power to run a top drive so I'm looking for a few of them. So far all 3 cummins have been in for total overhaul at 5-8k hours, really not the downtime you want on an oil rig. Plus when the rigs go down I dont sleep!

93old smoke

You still have the murphy engine controls? The big red rig setups were intended not have much fluctuating in load. They need a modern avr setup with under frequency roll off setting for what ya'll are doing. Would cure all the problems we're seeing on these units. What company are you working for? or pm me.

KD93

Nice analogy!