High hours on John Deeres

[Nick F]

Hi all,
I am looking at a 1974 Grand Banks 42 which has twin John Deere engines. Hours are 7000. How concerned should I be?

 

[Jmarsh203]

What model engine? I’ve seen jd6068 hit over 40,000 hours without the head ever coming off. It had 4 valve adjustments, 1 water pump and 4 idler pulleys with 4 belts changed with idler pulley not because they were bad. Jd engines are known for quality. That was a keel cooled engine btw.

 

[O C Diver]

Which engines? Probably not original.

Owner maintenance will probably be a bigger factor. I have a 4045 in my trawler and expect 20,000 hours. John Deere rated mine 10,000 hours in commercial (mining, logging, and agriculture) applications.

Ted

 

[Insequent]

My guess is that they are the original engines as approx. 145 hours per year seems fairly typical. I say this based on polls that have been made on TF for annual usage of boats like this. Probably weekend and one short annual vacation for the owners(s) over the years.

If the hours were fairly regular, and in particular no long multi-year periods on non-use, then I would not be at all concerned. The proviso is of course that they were regularly maintained with oil and coolant changes etc.

Engine life is better assessed by fuel used rather than running hours but with 1974 engines that info is probably unavailable. These days the instrumentation will give both hours and fuel, which will tell you how hard, on average, they have been worked. I doubt that a pair of old JD's in a GB42 have been worked hard at all - not enough power to plane, so likely to have been at 50-75% throttle nearly all their life.

The engines are likely the old 6404 rather than the newer 6068's. I'm not sure if parts are an issue for the former. Some searching on Boatdiesel.com might give some more pointers. Try and find am experienced engine surveyor - their overall knowledge is just as valuable as their inspection of the actual engines in question.

 

[rslifkin]

I'd definitely consider a good engine survey (including compression checks, etc.). Basically make a good effort to assess the current condition of the engines. If they check out well and there's no indication of things being excessively worn, they should have plenty more life left in them.

It's hard to really nail down the lifespan of an engine as operating conditions, maintenance, etc. varies widely. And plenty of engines get brutally killed by avoidable factors rather than wearing out.

 

[Nick F]

Thanks for contributions so far. Engines are listed as 6404DF/AMMarine 404.

 

[O C Diver]

My guess is that they are the original engines as approx. 145 hours per year seems fairly typical. I say this based on polls that have been made on TF for annual usage of boats like this. Probably weekend and one short annual vacation for the owners(s) over the years.

John Deere wasn't offering marinized engines in the 70's, 80's, and maybe not till the late 90s.

Ted

 

[rslifkin]

John Deere wasn't offering marinized engines in the 70's, 80's, and maybe not till the late 90s.

Ted

Other companies did marinize JD engines before that though. Such as American Marine with the JD 6404 and then Lugger started marinizing some JD engines as well. Both were available in the 70s IIRC.

 

[koliver]

John Deere wasn't offering marinized engines in the 70's, 80's, and maybe not till the late 90s.

Ted

Ted:
Nick is looking at a 70s GB with original marinized Deeres. Another 70s GB in Nick's and my own YC also has original marinized GBs. Those are in BC, Canada.

 

[Comodave]

I would do some checking on parts availability before buying. Some of the older marinizers may not be in business anymore.

 

[Nick F]

The engines are "American Marine", so I guess that American Marine was the marinizer.

 

[Comodave]

The engines are "American Marine", so I guess that American Marine was the marinizer.

Then do some research and see if parts are available or not. That may make the decision for you as to whether or not to buy the boat.

 

[mvweebles]

The engines are "American Marine", so I guess that American Marine was the marinizer.

American Marine (GB) did the marinization. Internal engine parts are likely available from Deere. Not sure about the transmissions (these were counter rotating engines). Marinization will be hit or miss. Pumps will be easy. Items such as exhaust manifold might be difficult and expensive if you're lucky.

Your best source will be a GB club.

Good luck

Peter

 

[sunchaser]

Hi all,
I am looking at a 1974 Grand Banks 42 which has twin John Deere engines. Hours are 7000. How concerned should I be?

An off topic question, is the vessel wood or FRP?

 

[Nepidae]

High Hours

First, I'd think that a GB in the '74 timeframe would have Ford Lehman engine(s). I believe that most GB came with 1 of those.

I'd contact GB and ask if they have records on that yr & model. A great benefit that GB is still producing boats.

Second, while 7000hrs on a diesel engine aren't necessarily a lot the best way to 'test' the engines is with an oil analysis. There are several companies that you can send a sample to that will give you a full rundown of the health of the engine(s).

That way, no doubt.

Good luck.

 

[Nick F]

An off topic question, is the vessel wood or FRP?

She is fibreglass. This was the transition year. Hull looks good, although not yet surveyed.

 

[Nick F]

I'd contact GB and ask if they have records on that yr & model. A great benefit that GB is still producing boats.

Second, while 7000hrs on a diesel engine aren't necessarily a lot the best way to 'test' the engines is with an oil analysis. There are several companies that you can send a sample to that will give you a full rundown of the health of the engine(s).

Oil samples are at the lab right now. Waiting for results.

One concern is availability of parts for the John Deere 6404 engine. Does anyone have any knowledge of this?

 

[BandB]

Wifey B: I'm confused. You said high hours in the title. Then you said 7000 hours? Did you mean 70,000? That would be high. We've got from 2000 to 4000 on our Deere's. Now I expect everyone to look confused that we have Deere's. Think a bit people. First who figures it out, wins a year free membership here. Ours are only 8 years old.

Seriously, the hours are just not an issue with tractors. Nothing Runs Like a Deere.

Lot's of great marinizers, but the engine didn't change much whatever label you put on it.

 

[Nick F]

Hi Wifey B,
Thanks for your reassuring comments. I hear good things about the later John Deere power plants, but have also heard negative comments about the American Marine version. It was fitted to a few Grand Banks and then no more for some reason. It may be that the core engine is good, but that if I need, for example, a new marine manifold it is no longer available.
Still trying to sense a consensus in the anecdotal information - including yours.
Thanks for the input!
Regards,
Nick

 

[mvweebles]

Nick - these were only marinized by American Marine - Grand Banks. This is now a 50-year old engine. You really need to find a source via the GB owners group. Your points of failure are not the engine, it's the other stuff. Bottom line is there are only a handful of these engines out there. Transmission and marinization are the failure points, not the engine itself. Sometimes there is a source for NOS (new original stock) items that solves all problems. Sometimes there isn't and it can be a serious problem and an ongoing issue/expense. Some of the early Willards were equipped with Unicorn engines that were ultimately replaced not because of the engine but the marinization.

In short, asking about the eninge is the wrong question. The engine is fine and will last a long time as long as the marinization and transmission do not mutiny to kill the engine.

Just my opinion

Peter

 

[IRENE]

Wifey B - those Deeres are on your big boat generators, me thinks…

 

[BandB]

Wifey B - those Deeres are on your big boat generators, me thinks…

Wifey B: You're such a Lugger, Deere. :lol: You'll end up in Northern Lights.

 

[IRENE]

…and a side of Yanmar too (3YM30).

 

[Comodave]

Nick - these were only marinized by American Marine - Grand Banks. This is now a 50-year old engine. You really need to find a source via the GB owners group. Your points of failure are not the engine, it's the other stuff. Bottom line is there are only a handful of these engines out there. Transmission and marinization are the failure points, not the engine itself. Sometimes there is a source for NOS (new original stock) items that solves all problems. Sometimes there isn't and it can be a serious problem and an ongoing issue/expense. Some of the early Willards were equipped with Unicorn engines that were ultimately replaced not because of the engine but the marinization.

In short, asking about the eninge is the wrong question. The engine is fine and will last a long time as long as the marinization and transmission do not mutiny to kill the engine.

Just my opinion

Peter

Agree 100%. Make sure the marinazation parts are available. The engine parts are from John Deere and are most likely available.

 

[twistedtree]

Does anyone know what marinization parts we are talking about on this engine? If it's just a raw water pump and a heat exchanger, that shouldn't be a big deal, even if you need to adapt an off the shelf heat exchanger. Those are readily available is all sorts of capacities and configurations.


The exhaust manifold is what I'd look at. If Deere offered a jacket cooled exhaust manifold, then I think you are in luck. If the manifold is an American Marine creation, then I expect it's a unicorn.

 

[Nick F]

For sure its an American Marine manifold.

 

[Sailor of Fortune]

For sure its an American Marine manifold.

I would investigate if a Northern lights manifold could be fit/adapted. I know they are no longer made but lots of them around. They used the JD for their Gensets and Lugger engines for years

 

[C lectric]

With the discussion it just occurred to me to ask John Deere themselves.

They now, and for a number of years, do their own marinizations so if the change in policy included that block then J.D. mflds. may be available. It would be worth while asking.

Get the specific engine model number AND the serial number and contact them.

 

[twistedtree]

With the discussion it just occurred to me to ask John Deere themselves.

They now, and for a number of years, do their own marinizations so if the change in policy included that block then J.D. mflds. may be available. It would be worth while asking.

Get the specific engine model number AND the serial number and contact them.

This is a great suggestion, and Deere’s parts info is all online. I took a quick look yesterday, but see there are several variants of the 6404 and I don’t know which the boat has. A full serial number would be ideal. I don’t know how long Deere had been doing this, but on the big sticker on top of current engines are a whole bunch of 4 digit numbers. My engine have probably 30-40 of them. Each describes what the engine has in some specific area. The first two digits are that section of the engine and parts catalog, and the second are the particular config that the engine has. I’m making up these numbers, but let’s say that numbers in the 2400 range are the oil pan. 2401 might be one oil pan config, and 2402 a different config. I saw several exhaust manifold options, but all appeared to be dry.

BTW, a dry exhaust manifold isn’t necessarily the end of the world. Higher HP rated Cummins QSM 11 engines have a dry exhaust wrapped in insulation.

 

[Nick F]

......... A full serial number would be ideal. .............

Thanks for this, TwistedTree.
The serial numbers are 378727R and 381049R. I will do some online digging as you suggest.

Regards,
Nick