6.5 military surplus engine

[56pan]

I was at an antique engine show yesterday and a fellow there was selling new 6.5 mil. surplus engines. I'm needing a new engine for my '93 Chevy 2500 2wd, and at $2500, these are considerably cheaper than other sources I've looked up. I asked him if his 6.5 engines had the NA comp. ratio or the turbo comp. ratio and he insisted they were set up for turbo operation. Has anybody had any experience with one of these mil. surplus engines or knows what other identifying characteristics I can check to see if it's an NA engine? I seem to remember the comp. ratio on my old '85 6.2 was 21 to 1, and on my '93 6.5 TD it's 19 to 1. What block casting numbers should I look for and where are they located? Any help would be appreciated.

[Robyn]

Most all the NA engines are Turbo compatible.

The 19:1 did not come out until tha late stuff. 98-2000 somewhere in there.

The casting number is on the LH side rear right on top of the bellhousing flange, just below the head deck

Last 3 didgts. 929, 599, 506 are all possible

the 929 and the 599 will have 12mm outer main bolts and no oil squirt holes.

The 506 blocks generally are to be shunned at all costs.

The ones early 506's had the 12mm outer bolts and the large oil squirts. These were made for the 97 model year and were very prone to cracking the main saddles through the oil squirt holes.

Been there done that. :eek:

A 599 or a 929 would be an early block.

Any of these can be used with the turbo. Just keep your max boost to no more than around 12 PSI.

All early 6.5 TD's had 21.3:1 comp and were fine with it.

The late stuff had the 19:1. This was GM's last ditch effort to keep things alive a little longer

My 94 has 268K on the original pistons so ?????????/ go figure.

The only real savings with the lower compression is that it will allow higher boost.
Now this said, unless you use an aftercooler more boost (above 12 psi) is a waste anyway due to high intake temps and resultant high EGT's that come with it.

Keep it close to stock and it will be a happy little camper.


Good luck

Robyn

[56pan]

Thanks for your time, Robyn. Just exactly the information I was looking for. Particularly the block casting numbers and location.:)

[midniteplowboyy]

Unless its a 506 AMG block, thats the one to have. Look for two diamonds under the intake cast in the center of the valley of the block, also 506 will be cast in dots on each side of the valley. The 506 is the best or worst block, just depends who built it.

The turbo HMMWV's use van heads, so you really dont want one of them unless swapping heads. Plus most turbo engines were in armored HMMWV's, they were worked alot harder(about twice the weight).

[JohnC]

Why would the military be unloading NEW engines? Past the best-if-used-by date? Caveat emptor!

[midniteplowboyy]

Well some AMG's are not so new now, they been building them for around eight years now. I was just pointing out that all 506 were not bad, to inspect closely you might get lucky.

Most HMMWV pull out engines will be 6.2's, some will be GM 6.5's and a few AMG's will find there way through.

I wouldn't be surprised if there were 50,000 AMG blocks in HMMWV's now.

[56pan]

The fellow selling the mil. surplus engines said the military was pulling the NA 6.5's out of vehicles, (I'm assuming the HMMWV's), and installing 6.5 TD engines. The new ones he has are spares that were no longer needed. Said he had some rebuilt NA 6.2's also.

[midniteplowboyy]

That feller lied. We install around 32 new AMG 6.5N/A engines a day into HMMWV's.

[56pan]

???? First time I'd ever met the guy, and yeah, maybe he's a BS artist. The engine on display had all the looks of a new factory engine and was sitting in the bottom half of an olive drab military looking shipping container. Anyhow, I've got to head back overseas to work for 4 wks. and will go over to his place when I get back. He's just right over in the next county. He said he had 15 6.5's available and would put one of them on the dyno and run it for me before we made any deals. He can do the R&R of my old engine with his new one also. I won't have time to fool with it, but am very careful before laying down that kind of money. I'll post here how this thing comes out when I get back home. Thanks for all the input.

[chevytuff]

He has been getting the motors from Govt. Liquidation, I bought two "Rebuildable" 6.5's from Gov liquidation back in 07 for 250.00, Both had thrown a rod due to a blown head gasket. One of them a 98 block which in the process spun a main bearing and ate the crank up I sold for 500.00 and the other a 2000 or 2001 block (Thickest GM Casting been a minute since I looked at the date code) before AMG took over I have sitting on an engine stand torn down waiting to be rebuilt. A quick way to tell scammer from something that could be legit is does it appear to be freshly painted? The heads are usually the telltale as the front and rear "Accessory mounting surfaces of the head should be bare metal, You should also see factory "Paint" inspection dots on these surfaces, these can be multi colored and are about the size of a dime. Look where you accessory brackets would mount up for these. If it is a "New" motor andt if its not an "AMG" it should have a "General Engine Products" label which was the division of General Motors whom produced the Motor for the Humvee affixed to the drivers side valve cover. If it has been freshly rebuilt from the government than it should have a Mylar (Aluminum type sticker Material) affixed to the valve cover with a date of rebuild stamped on it. The timing cover is a dead giveaway usually as well. If it is anything other than Bare aluminum then it has been rebuilt or painted in a non-factory manner. I have bought several items from Gov liquidation and have seen "New Old Stock" Items surplused off at extremely cheap prices, I have also seen people buy Junk at these auctions throw some paint on it and sell them for new prices. I have talked at length with the DRMO People at several of the bases waiting for my turn in line to claim my lot, They are friendly and most will tell you what is and isnt junk and what to watch out for. Most all of the Military Surplus motors New and Used come in the Shipping Containers, The containers themselves weigh 500 lbs a piece. (Dropped the lid of one on my foot and broke 3 of my toes in the process)

[Chief919]

There are some low mileage motors getting pulled and sold. The USMC has been upgrading M998A2's, that have 6.5NA's, to uparmors with 6.5 turbos. My 94 has one I got with such little use the paint was not even worn off the grooves in the pulleys. The last inspection the GEP sticker on the valve cover that said it was exempt from emissions requirements due to national security caused some head scratching.

That said, most surplus motors will be well used. I have seen brand new 6.2's and 6.5's at DRMO, but they are rare.

[56pan]

Thanks Chevytuff for such very good information. And your input too, Chief 919. I'm back home, and am fixing to go see these engines this morning and have printed off the posts from Robyn and Chevytuff to have when I look at them. I think these are possibly the low mileage engines the Marines are pulling and replacing, as I'm located in NC and I've seen these engines offered at LeJeune over on the coast on govliquidation.com. That would be a two hour drive for this guy who's selling them. At least I'm a more informed consumer now.

[Subzilla]

56pan,
Did you buy these engines? Where in NC are you? I'm in Concord and I've got a guy in Charlotte trying to offload a couple of military 6.2's on me. Just wondering if they're the same???

[56pan]

Subzilla,
Yes, I bought one of his new 6.5 NA engines. The guy's name is Jim Henry and he's in Albemarle, in Stanly county. Spent a lot of time with him and the engine before I bought it. We hooked it up and started it. He's been in the surplus business for 25 yrs., and has been burnt on selling these engines before and is very careful to check them out. The military puts all the new engines it buys on a dyno right out of the shipping can, and runs them. He says that he's had some engines that the guys doing the dyno run didn't purge the air out of the cooling sys. properly, and the head gets hotspots and cracks. He always pulls the heads now and sends them to a shop for checkout. We left the water manifold off with the block full and there were no bubbles. He gives a 30 day warranty on the engines. If the thing doesn't come apart on me, he's saving me quite a bit of money. I'm going to have it installed when I get back home in Sept., and I'll let you know how it turned out after some mileage.