All the M1123's

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SinDiesel
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All the M1123's

Post by SinDiesel » Tue Nov 15, 2016 3:51 am

I've noticed lately that there are more and more M1123's coming out of Georgia. Almost all seem to have completely black engines including black painted intake manifolds which I remember tends to signify the motor has been rebuilt of remanufactured at one time or another. My question is, shouldn't a remanned engine have oil pressures of 30 psi or better and not less than 20psi like I'm seeing on most of these units. If needed can these rebuilt motors be rebuilt again now pro only being .060" over if not more or is that too close to the service limit or more importantly than the bores can the cranks be reground potentially a second time and matched with the corresponding journal beirings.

Anybody else have comments, concerns, recommendations, or feedback on these units?


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Re: All the M1123's

Post by dilvoy » Tue Nov 15, 2016 12:00 pm

Usually an engine with everything painted black, like intake manifold and injector lines is a sign of a rebuilt engine. You would have to look at the data plate that is attached at the time of rebuild to see what they have done to the bore and crank. As far as photos of low oil pressure, The gauges are not too accurate just like on most cars. The gauges are just a guide and not calibrated for exact performance and even if they were, bad electrical connections from the sender and issues with grounding from years of sitting outside can make them read incorrectly so I wouldn't put too much stock on a low oil pressure reading if the vehicle is running nicely.
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Re: All the M1123's

Post by Retired War Horses » Thu Nov 17, 2016 6:46 am

A little birdie told me the M1123's have Melton rebuilds in them from "reset", those melton motors have Chinese blocks.
I'm told the chinese blocks have no casting numbers as GM and GEP do for identification.
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Re: All the M1123's

Post by Lionel » Fri Dec 02, 2016 11:55 am

Yep, I can confirm. Melton motor with no casting numbers. Thank goodness I've got spares.
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Re: All the M1123's

Post by dilvoy » Fri Dec 02, 2016 3:20 pm

That sounds bad! I wouldn't trust the metallurgy on those "Fire Cracker" replacement blocks from China being as good as what IH was producing.
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Re: All the M1123's

Post by Lionel » Sat Dec 03, 2016 4:06 am

I'm filing a formal complaint with them as it was sold as having an Optimizer. Doubt it'll do much good though.
1994 HMMWV M998A1
1995 HMMWV M1025A2 GMV
2002 HMMWV M1024A2 GMV
2001 HMMWV M1043A2
2001 HMMWV M1123
2000 JD M-Gator
2001 Kawasaki M1030B1 (650)
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Re: All the M1123's

Post by Ted Gates » Sat Dec 03, 2016 4:24 am

WOW! False ad if you ask me IP. Lionel, post that on ss.

Good time to turbo it though.

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Re: All the M1123's

Post by Gadget » Tue Dec 06, 2016 11:17 am

They may just have another 400 of those soon. End of Jan. Bid will be awarded to demil them and then sell in GA.
1100 of them are working thru the system in Ca to sell. Wonder how long till they come down to the 10k mark?
Last edited by Gadget on Tue Dec 13, 2016 7:35 am, edited 1 time in total.

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Re: All the M1123's

Post by SinDiesel » Mon Dec 12, 2016 5:19 pm

Steve,
That little birdie is now also confirming some of what you said as some of the auctions are now showing pics like this one:

Image

If these blocks are in fact made in China, What I would like to know is how are foreign manufactured critical component blocks (by non-Nato countries) finding their way into american equipment. Sounds like Melton might have some explaining to do?

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Re: All the M1123's

Post by Retired War Horses » Tue Dec 13, 2016 7:03 am

I'm no expert on melton, they have been around for many many years. What I know of Chinese caster blocks is only what I know from the internet. I have only heard that the melton rebuild have Chinese blocks. Anyone who has a melton just needs to look for the casting numbers, if it has them, your ok...the Chinese blocks are void of casting numbers from my research.
Remember, these motors were installed along time ago under contract during reset. Everything today comes from GEP, but I'm not sure who is doing eng rebuilds for the govt.
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Re: All the M1123's

Post by 86humv » Tue Dec 13, 2016 7:46 am

I called Melton....they said no chinese blocks.
They did these motors for Marines and Army.
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Re: All the M1123's

Post by Lionel » Tue Dec 13, 2016 9:54 am

Yeah, Uh huh. :roll: Someone must have stolen the casting numbers.
1994 HMMWV M998A1
1995 HMMWV M1025A2 GMV
2002 HMMWV M1024A2 GMV
2001 HMMWV M1043A2
2001 HMMWV M1123
2000 JD M-Gator
2001 Kawasaki M1030B1 (650)
2000 Kawasaki M1030M1

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Re: All the M1123's

Post by Ted Gates » Tue Dec 13, 2016 12:06 pm

I obtained a 6.2 melton and it was new, ran once and now not running. Someone did not set the valve spring retainer correctly and it grenaded that cylinder.

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Re: All the M1123's

Post by johncarrol » Fri Mar 09, 2018 12:05 pm

I purchased a surplus 6.5NA a few years ago from a guy that got it at a surplus auction pulled from a HMMWV. It had a tag on it from the company that rebuilt it with the date of rebuild and bore and crank journal diameters that were marked "standard". I purchased a 2005 M1123 in July 2017 and when I pulled the engine cover off, I was expecting to find either the original GEP engine or a rebuilt one with the same type of tag. What I found was both the 6.5 and the 4l80E with tags that read GM remanufactured engine and transmission with dates 2010. The casting code on the block indicated that it was cast in 1997. I didn't know GM rebuilt engines and transmissions, only produced new ones. At least the quality of the rebuild should be good. Does anyone have any more info on GM rebuilding engines for HMMWVs?

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Re: All the M1123's

Post by Ted Gates » Sat Mar 10, 2018 4:10 am

97-2000 year 6.5td blocks from gm have a casting design flaw on number 8 cylinder. It was on a certain percentage of blocks. Some last a few thousand miles, other serval 10s of thousands mile. Some haven't failed. I have 6 of them with bad #8's.

Best advice is to let engine warm up before revving/hard use. Check oil and coolant often. This is true for all diesel engines!

The trans should be good for many are tested/dyno'd after rebuild.


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