Cummins vs John Deere.....

The friendliest place on the web for anyone who enjoys boating.
If you have answers, please help by responding to the unanswered posts.

BruceK

Moderator Emeritus
Joined
Oct 31, 2011
Messages
13,561
Vessel Name
Sojourn
Vessel Make
Integrity 386
Boats, like cars, have evolved and improved over the last 30 years. The faithful IG36 with Lehmans, though not getting any younger, is largely where I want it after 4 years owned. Staying with the trawler concept, my thoughts turn to a modern version. Here, the essential options are Integrity, Clipper (like MT), Mainship, Alaska, (last 2 much higher powered than first 2), and maybe Beneteau Swift. The old IG still has most features,some better than newer boats. Like trading twins for single, typically coming with thrusters both ends. That`s my threshold question to mull. Especially as it likely involves $250K changeover.
What I`m wondering. Integrity has gone from fitting Cummins 220hp to John Deere 225hp. Clipper still fits Cummins, incl Diamond series, some are 270hp from memory, and there are used single and twin versions.
Without starting a Ford vs GM type debate, is one preferable, or(as I`m thinking) are both good things to have in the ER?
 
Last edited:
I think both JD and Cummins make first class engines. But if I were repowering I would buy the essentially brand new factory reconned Cummins B engine (in hps from 210 to 370) at about half of a new Cummins QSB or equivalent JD.

David
 
I think both JD and Cummins make first class engines. But if I were repowering I would buy the essentially brand new factory reconned Cummins B engine (in hps from 210 to 370) at about half of a new Cummins QSB or equivalent JD.

David

Yup.

Excellent support worldwide, from both the factory and the aftermarket, make the Cummins the obvious choice for me.
 
I think both JD and Cummins make first class engines. But if I were repowering I would buy the essentially brand new factory reconned Cummins B engine (in hps from 210 to 370) at about half of a new Cummins QSB or equivalent JD.

David

Thats exactly what I did for my repower. :)
 
To the extent there are differences, I think it's more due to application than anything else. My totally unscientific take is that the Cummins get run at higher output levels, and get built into boats with marginally designed sea water systems. The result, quite predictably, is problems.

Deere's on the other hand, seem to be used in lower output applications in boats with more thoughtful installation designs. And few problems arise. On BoatDiesel.com, Deere's almost never come up for discussion.

So I would agree with Dave that both are excellent engines, and success depends much more on proper operation, installation, and maintenance.
 
To the extent there are differences, I think it's more due to application than anything else. My totally unscientific take is that the Cummins get run at higher output levels, and get built into boats with marginally designed sea water systems. The result, quite predictably, is problems.

Deere's on the other hand, seem to be used in lower output applications in boats with more thoughtful installation designs. And few problems arise. On BoatDiesel.com, Deere's almost never come up for discussion.

So I would agree with Dave that both are excellent engines, and success depends much more on proper operation, installation, and maintenance.

100% agree! I consider myself a Cummins man having owned 4 of their engines. When considering options for my Cherubini repower I naturally considered a 4BT recon as an option. While the 4BT was a decent option, it clearly doesn't enjoy the reputation that it's big brother the 6BT has. Also it was never really adopted by the trawler manufactures. In this size range the JD 4045 clearly owned the market between these 2 manufacturers. The 4045 is considered a much smoother (less vibration) running engine with better fuel economy and great trouble free life expectancy.

Ted
 
My JD4045 runs smoother than my friends' non-JD engines.
 
Last edited:
About how much would a re man 370 be still in the crate?
 
Seams like the 370 hp version was the problem child when ran at that level of output for any length of time. The 330 didnt have as many problems, even tho it was basically the same engine. The 210, 250, etc (non aftercooled) were GREAT engines. The 4BT tended to shake like a dog $hittin a peach seed, especially at idle. But, the B and C series both shook a bit.
 
About how much would a re man 370 be still in the crate?

In 2011 they were $19,000 each.

Only about a thousand more than the 330's I bought.

In my opinion 370 HP is too much for the 6B block. The 330 does great but it does great, again in my opinion in a situation where you generally run at low power settings and occasionally run at higher power settings.
 
I had a 330 on my Nordic Tug and now have two 370's on the Albin. All good so far.
 
How are the local dealers in Australia? I know Deere has good dealers in the Ag industry, we used to work with several in the Sugar Cane industry. How about Cummins?
 
A search suggests Cummins have Australia wide marine service. Are Onan part of Cummins, I think I remember ordering a start solenoid from them in Adelaide, South Aust, they were quick to respond.
 
A search suggests Cummins have Australia wide marine service. Are Onan part of Cummins, I think I remember ordering a start solenoid from them in Adelaide, South Aust, they were quick to respond.

Cummins bought Onan several?? years ago. Seems like a good fit.
 
Two completely different engines. We want to have a Helmsmen 38 built in the coming year or so. The only option on the 38 is the Cummins. Now the base model comes with the 380HP and not the 250HP.

Cummins is high output. No matter how you slice it. More issues and more complexity. Not a good thing on a boat. There is a reason Nordhaven used mostly Deere engines in all its vessels. The N41 and N51 use a different engine. Sure wish Beta made a mechanical 300HP or higher.

I think the Cummins is a great engine, we were a. dealer for them long ago and they were good but times have changed thanks to TierIII Not. a good thing.

When we get ready for our build I will see if there is any way we can go with Deere. Low output, still Tier III. That would be my preference and if not then we will go with Cummins. And keep spare parts, especially the fuel side of things.

I don't think you can go wrong with these two engines no matter what your choice. I'd stern hard to port away from Yanmar or Volvos. Very complex engine.

Love to hear from any John Deere owners out there. And what your experience has been from all angles, including parts and service. That could be a deal killer right there.

Cummins has an awesome network of dealers and parts etc.

And conversely, love to hear from Cummins owners as well. Any issues you see in particular?
 
Despite being relatively high output, the B series Cummins (including the modern electronic versions) has a good reputation for durability. In a Helmsman 38 you'd normally be running that Cummins well below its max continuous output let alone full power. So I wouldn't expect durability to be even a remote concern.

Engine choices in a full displacement boat are a bit different, as you can't really make use of much surplus power. So it makes more sense to choose an engine that makes only slightly more than the power you need and is rated to run at or near WOT most of the time.

On the other hand, the H38 is semi-displacement, so you can almost always use more power. But normal cruising will be much further below max power unless you under-power the boat, so the engine doesn't need to be rated as heavy-duty, as it doesn't need to handle sustained WOT operation. It just needs the "max continuous" power output to be at least as much as required for the fastest target cruise speed.

As an example of typical power usage profiles in faster boats, my own boat has 2x 340hp engines. At a typical fast cruise for us (~17 kts) power demand is somewhere around 180 hp per engine as best I can estimate. Drop to our typical slow cruise of ~6.5 kts and each engine is only being asked to put to maybe 20 hp. At that level, they're very lightly stressed to the point where even a high output engine with a short lifespan if run hard will live a long life at that kind of output (assuming it's not suffering from any issues related to under-loading).
 
Thank you

Thank you for your reply. All great information for sure.

I do believe the Cummins is a good engine. I know there have been some fuel-related issues at times. But usually a faulty pump etc. And just in a few cases. We'd be a single engine and I used to be a diesel tech on boats so I have the tools and pretty good know-how. I would need to get up to speed on the new Cummins engines.

I am a little concerned there is no wing engine or generator backup engine solution for the Helmsmen but not overly so.

Thanks again, any other info is appreciated.

take care,
Kirk
 
Kirk: Our 38E had a 380 Cummins and it performed admirably in all sea conditions during the 2 seasons of cruising SEAlaska and BC. It was coupled with a ZF transmission.
Our 46 due in Seattle this March, will be powered by a John Deere 6090SFM85 rated at 500hp, coupled with a ZF taransmission. The 46 will be about 50,000 lbs loaded and we like the additional power and speed the engine could offer. By the way, Helmsman would happily install a John Deere if you wish in a 38E.
Robert
 
Kirk, in 2014 I repowered with 6bt 210 Cummins. The factory 'recon' engines, with new engine warranties, were $15k each. I now have 1500 hours on these engines and have had no problems with them at all. They start on the first revolution, don't smoke, give good fuel economy. I run the boat up and down to SE AK each summer and consider them to be the most solid, reliable system on the boat.
 

Latest posts

Back
Top Bottom