Yanmar 4JH4E

[Ian_Edwards]

Hi,
Three questions:
1) My new to me boat, has a Yanmar 4JH4E engine, I can find an on line manual for a 4JH4AE, but not for the 4JH4E, is there any substantial difference between the E and the AE models?
2) Does anyone know where I can locate a Key for the Yanmar engine coding, what does each character signify? Some of it is obvious, e.g. 4 = 4 cylinders, but he rest is mystery to me
3) I'm looking for a fuel used versa rpm graph, so I can begin to get a handle how much fuel I'll use. And I know that the actual fuel consumption will depend on the prop, wind and wave conditions as well as the hull shape and mass of the boat etc. I've searched on-line but haven't found one as yet. Does anyone know where I can find one?

As always any help the forum can offer will be gratefully received.

 

[Mistroma]

According to the service manual the 3 or 4 relates to number of cylinders as you mention. and the JH4 part is the engine series. The only numbers listed were: 3JH4E, 4JH4AE, 4JH4-TE, 4JH4-HTE

As far as I can see, AE seems to be normally aspirated with TE turbocharged and HTE a more highly tuned version of TE (aftercooler?). However, I could only find a 3 cyl. 3JH4E and no mention of a 4 cyl. 4JHE.

I did see a 4JH4E listed elsewhere and it seemed to have the same output and spec. as the 4JH4AE apart from a 60A alternator instead of 80A. I also saw a comment saying that the AE was a newer version with a mod. to improve fuel consumption.

I have a 4JH4AE and can pm a copy of consumption diagram and service manual if that's of interest. However, it looks as if the E model might be slightly less fuel efficient than my AE model.

UPDATE: You can download specs. with consumption figures for E & AE models here (scroll to bottom of page).
http://users.comcen.com.au/~minards/marine_jh.html

 

[PeterBoater]

The Yanmar engine coding for my 4JH2-UTE is:
4 cylinders
JH fresh water cooled
2 Second generation
UT Ultra Turbo Charged
E Export model

http://shop.torresen.com/marine_die...getitle=Yanmar+Marine+Engine+Identification++

 

[VicS]

Well here is the technical stuff for the 4JH4E

http://shop.torresen.com/utility/includes/content/yanmar/sales_lit/4JH4E.pdf

and for the 4JH4AE

http://shop.torresen.com/utility/includes/content/yanmar/sales_lit/4JH4AE.pdf

Looks like the AE is a later version with not many differences

The performance curves should give you the information you require

 

[Ian_Edwards]

Thanks

Thanks for the info', it's exactly what I was looking for. I'd spent more time than I'd care to admit to searching the world wide web for the info' without success.

Thanks again and a Happy and Prosperous New Year when it comes.

 

[Norman_E]

When I bought my boat, which has a Yanmar 4JH series engine, E P Barrus very kindly gave me a copy of the original Yanmar Instruction Manual, which contains all the details you need to service it.

 

[Ian_Edwards]

Hi,
Just out of interest I've combine the two fuel versa rpm graphs.

The AE version (solid line) is significantly more fuel efficient at low revs.

Since I now own the older less efficient "E" version, I can't help wondering if it is possible to up grade the engine (it only has 200 hrs on the clock). I'll ask some experts when they are back to work in the New Year, but does anyone on this forum know if an upgrade is possible?

 

[VicS]

Hi,
Just out of interest I've combine the two fuel versa rpm graphs.

The AE version (solid line) is significantly more fuel efficient at low revs.

Since I now own the older less efficient "E" version, I can't help wondering if it is possible to up grade the engine (it only has 200 hrs on the clock). I'll ask some experts when they are back to work in the New Year, but does anyone on this forum know if an upgrade is possible?

I must be missing something

The dotted line shows a lower fuel consumption than the solid line surely ??

The dotted line does not seem to agree with the curves in my links either


I cant see a significant difference between the two engines, at least looking at the fuel consumption vs rpm curves in my links.

 

[Mistroma]

I checked the graphs in the docs. in the link I sent earlier and was able to overlay both fuel curves. So curves for AE & E seemed to be identical.

I imagine that the links in later posts pointed to the same docs. as VicS said he couldn't see a difference either.

As far as I could see, the AE mod. was only meant to improve the economy slightly. The graph certainly agrees reasonably well with my own records for fuel usage on AE model. We did 2000nm this year and have had the boat since 2009 so I have quite a lot of data. I think you'd be reasonably safe using these graphs as a rough estimate of likely fuel usage.

 

[Ian_Edwards]

Mistake

Yes, your right, I made the mistake of matching the lower end of the curves, the top ends meet at 3000 rpm and 12L per hour. But the lower end of the "E" ends at about 1600 rpm and 1200 rpm for the "AE". I'd assumed that the rpm at the low end of the graphs stopped at the same rpm. And I got the to lines mixed up!

 

[Latestarter1]

Ian,

4JH is a brilliant little motor but I think there is a risk when you drill down too deeply into any engine spec sheet.

Unlike larger brothers Yanmar use realistic ISO 8665 for the JH which is good, however #'s carry the health warning that they are crankshaft #'s obtained under laboratory conditions with a +/- 3% tolerance, which is also extremely good as manufacturing norm is +/- 5% with some engines being as high as +/- 6%.

Also remember that the #'s are quoted at crankshaft, losses in KM4A transmission are typically around 5%.

Just enjoy the engine.

 

[Mistroma]

Ian,

4JH is a brilliant little motor but I think there is a risk when you drill down too deeply into any engine spec sheet.

Unlike larger brothers Yanmar use realistic ISO 8665 for the JH which is good, however #'s carry the health warning that they are crankshaft #'s obtained under laboratory conditions with a +/- 3% tolerance, which is also extremely good as manufacturing norm is +/- 5% with some engines being as high as +/- 6%.

Also remember that the #'s are quoted at crankshaft, losses in KM4A transmission are typically around 5%.

Just enjoy the engine.

OP was asking for a graph of "fuel used versa rpm graph" and docs. provided gave that information. I don't think he wanted much more detail, just a rough idea of the likely consumption. I think that the graphs are good enough for that and not far from actual figures I've been getting. Could be wrong but imagine he'll be happy with +/-10%.

 

[Latestarter1]

OP was asking for a graph of "fuel used versa rpm graph" and docs. provided gave that information. I don't think he wanted much more detail, just a rough idea of the likely consumption. I think that the graphs are good enough for that and not far from actual figures I've been getting. Could be wrong but imagine he'll be happy with +/-10%.

Did not seem that way to me.......

'Since I now own the older less efficient "E" version, I can't help wondering if it is possible to up grade the engine (it only has 200 hrs on the clock). I'll ask some experts when they are back to work in the New Year, but does anyone on this forum know if an upgrade is possible?'

 

[Mistroma]

Did not seem that way to me.......

'Since I now own the older less efficient "E" version, I can't help wondering if it is possible to up grade the engine (it only has 200 hrs on the clock). I'll ask some experts when they are back to work in the New Year, but does anyone on this forum know if an upgrade is possible?'

Ah, sorry. I assumed that was just because he'd seen a significant difference (i.e quite large) based on 2 graphs. However, it was pointed out that there wasn't a difference and graphs were identical (or almost identical). So no point in considering a modification that wouldn't make any siginificant difference to fuel economy.

Sorry about that, you are correct and I was jumping to the conclusion that OP wouldn't want to follow up on the mod. if it only made a few % difference (if that). The comment about help with a mod. came when OP saw differences at bottom end of 1.5 - 2.5 litres/hour in post #7 (pretty big % diff.)

When I overlaid the graphs they actually matched exactly so I couldn't see any difference at all.

 

[Norman_E]

As far as I am concerned the big issue about any marine engine is not consumption but reliability. My own 4JH series Yanmar has amply demonstrated its reliability, and has now run over 5000 hours. With the manual on board I cannot now be certain of its exact output, but 87 bhp at 3600 revs for short periods and up to 3400 rpm continuous rating comes to mind. It is model 4JH2DTE.