Should I swap to a 6.2?

[MadOgre]

you said it

 

[MadOgre]

Lmao

 

[MadOgre]

you said it LMAO

 

[marks86]

and in the military there are people whos job it is to work on these trucks so it god for bid a 6.2s cracks a head? they replace it and get it ready for action, I hurd that the fleet trucks in the military that are not driven often get started up and ran for an hour every week just to keep them from sitting to long, thats how meticulous they are

 

[Milblazer]

Yea its a military surplus. Still in a military crate. Apparently it was pulled for a 6.5 swap.

I bought one of those surplus motors and it had been recently been rebuilt. I just put the heads from it on my 6.2 when I was looking for my overheating cause. Everything was in excellent shape except for the precombustion chambers. They had some cracks but if they were within the margins for being reused. I got lucky getting a rebuilt engine I only saw in online pictures. Plus I turned around and sold that heavy ass green container for scrap and made some money back.

 

[columnshift]

So I currently have a perfect running 454 in the C30, love every bit of it except the 6 mpg. I have been thinking about throwing in a 6.2 any thoughts? I found one for cheap that might have a blown head gasket (all it says is coolant in the oil) that came out of a 1990 humvee. I could get it for under $400. What do you all think?

My thought is that then I could drop the 454 into my Camaro without having to rebuild it...

Maybe!

(note I didn't read anyone else's comments in this thread yet so what I say may be redundant)

From everything i've obsessively researched myself, 6.2's and 6.5's have a tendency to spontaneously DIE sending the crankshift south through the block. It is semi irrelevant to mileage - it sounds like you could have a super low mile 75k 15 year old one that could die tomorrow after running perfectly, and a 200k one that will soldier on. They are blamed for having weak crankshafts, which apparently is not true, and weak main bearing caps, which is also apparently not true... by what I can find, the problem is that the main webs crack due more to thermal cycling over time (not wear related) so that even with billet main caps and a billet crank it would still happen.

I'm not fully sure of the proper counters to this problem other than 1) don't care (use it for local use only and not worried if it breaks down), 2) fully inspect the block especially the main webs for cracks/probably to the magnaflux level, and it sounds like most WILL have cracks just an issue of how bad and how long it will run with them... since many are running, yet have cracks, obviously they can run with cracks, but also they can go just like a dam with cracks can hold water too but you can't know for another day or another year..., or 3) it sounds like the newest of the new AM General Hummer engines are built with new castings that finally solved this problem but i'm not even sure if they are in civillian junkyards necessarily.

 

[Stewzer55]

If you want to know how to make a 6.2/6.5 run, check out Heath Diesel Power.

 

[Chuck]

The new style hummer 6.5 are suppose to have no crank issues and a rebuilt one is 2500. I think they make more power.


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[da_raabi]

Lookie what I got!

Well after a long while I finally made the plunge. I had a guy offer to trade two 6.2 J-code diesels for an old big block I had so here they are! We made the trade last night!

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Real J-Codes from 1985. He said he knows one of them only had 40k miles on it!

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He asked if I was going to turbo, so I said yes. He goes "Well I've got a present for you then" and drops this monster in my hands:

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He said he got it out of an astro van he got that someone had put a Cummins and 1-tons in! Can you believe that? An Astro Van???

He was a really cool guy, it turned out to be one of those craigslist deals where you come away thinking there are still good people out there. Hell he even said if I wanted to drive out to his place that he's got one of those over-size military radiators I can have. Really nice guy!

Oh and Mr UPS man dropped this off yesterday too. 1 down, 3 to go!

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[marks86]

nice man, those are both cucv 6.2 diesels, those alt. and starter are wired to run 24v, f I were you I would just get a new starter and remove one alt

 

[da_raabi]

Thats the plan. I'm planning to do a decent tear-down and prep the block for a turbo setup. Looking at main studs/girdles, head studs etc. Should be fun, and I've got lots of extra parts!

 

[marks86]

Thats the plan. I'm planning to do a decent tear-down and prep the block for a turbo setup. Looking at main studs/girdles, head studs etc. Should be fun, and I've got lots of extra parts!

nice! do you have a fuel filter?

 

[da_raabi]

Not yet. I intend to run a fuel filter, oil cooler, intercooler, all kinds of extras. Should be a goo running motor when its done. I'm hoping I can make it perform too - hoping for around 250-300 hp.

 

[towjoe]

I have a M1028a2 with the 6.2. It has the 4:56 gears and all. If I drive it sensible around town I can get 15-16mpg. No towing or load just running around cruising. I bought a M1009 I was going build a daily driver out of because of the mpg claims. We started driving late 80's early 90's 350 tbi trucks. They average 17 mpg. My 454's only run 5-7 mpg in my one tons. I put a 350 in last k30 and it only gets 7 mpg. Been considering 6.2 in it. I just pulled a 6.2 out of a 93 Chevy bus

 

[marks86]

Not yet. I intend to run a fuel filter, oil cooler, intercooler, all kinds of extras. Should be a goo running motor when its done. I'm hoping I can make it perform too - hoping for around 250-300 hp.

my advice is run a screw on filter