military to civilian conversion

[bubba]

Let me start by saying hi, i'm new here.

I bought a 94 gmc bucket truck with a 6.5 turbo in it.
I drove it home and now it is smoking like a house on fire....just my luck.

I found a brand new 6.5 turbo engine that was manufactured for the military and i was wondering if it could work in my truck.
I was told i could take all the military stuff offf and just use it like a long block.
the turbo is not in the same place , is that was a problem?
the military motor has injectors on it...can they stay?

if you have not figured it out by now i have no clue about these engines so any advise would be great.

thanks

 

[Husker6.5]

Yes it will, as long as you use the exhaust manifolds and turbo off the 94 (provided the turbo is still good) and use the 94's intake assembly. Swap over the alternator, vacuum pump, A/C, etc and you're good to go. The military center-mounted rear turbo won't fit in the 94 engine compartment (it was designed to fit under a Hummer hood/engine compartment) so that's why you need to use the 94's intake, exhaust and turbo plumbing. Keep the military injectors in the new motor, they'll work just great.

Buy yourself a genuine GM Factory Service manual, either the DVD version or a print copy, (you can find them on eBay) for your '94 and you'll be good as gold.

 

[WarWagon]

Your current engine smokes from the oil fill cap or the exhaust? I would suggest figuring out what is wrong and if you can fix, re-ring, etc. on your engine first.

Possible bad blowby, blown head gasket, timing set wrong, turbo WG not staying closed, hole in piston or cracked heads/block, valve rocker button broken dropping a pushrod off.

The center mount turbo is a van engine. Heads, exhaust, and intake are different. Could also be a Hummer engine but I am guessing. Turbo oil supply and oil drain the center of the block would need to be plugged and use your heads.

I would check out boyceequipment.com out of Utah for a 6.2 engine tested with a warranty. Swap precups, deglaze the cylinders and new gapless rings. Use 6.5 heads for better injector clearance.
The 6.5 engine is bored out 6.2. Major difference is the injector angle in the 6.2 vs. 6.5 heads that causes some manifold clearance issues. Nothing I haven't solved running 6.2 longblocks with a 6.5 turbo. Precups only matter if you are going for a bigger turbo and more power.

 

[Will L.]

Welcome to TTS.
Check the angle of the bolts that mount the intake manifold to the heads. Hummer and van heads have the bolts at a different angle than the truck heads. If you swap the heads off your old engine, you have to replace the head bolts, they are 1time use. Research using new bolts vs. head studs. If you plan on keeping the truck long term, ARP head studs are the way to go.
Before you start turning wrenches, read the stickys, it will save you money, time, and aggrevation.

 

[bubba]

it is smoking from the exhaust, from the dipstick and from the hose at the turbo....and air filter.

so i am a bit confused...do i need to use the heads from the truck or just the intake, exhaust manifold and the turbo?

 

[Husker6.5]

You will need to use truck heads, as the heads for center mount turbos ports are at different angles than truck heads (sorry, it was REAL late at night/early this morning when I posted, pulled an all-nighter). I would be VERY hesitant to use the heads off of your 94, even if they check out good, as the 94's are notorious for head failure due to cracking between the valve seats from over heating (see my signature). Use aftermarket heads or heads off of 96+ trucks, they have about 4lbs more metal in them and don't crack across the valve seats into the coolant passage. Brand new aftermarket truck heads, complete with valves, springs and retainers are available for around $350 each if you shop around (PM me and I'll give you my source for the source for most of them in the U.S. and the lowest cost I could find).

Also, I would SERIOUSLY consider upgrading the motor to '97+ cooling specs (130 gph water pump, bigger fan, '97 crossover with dual thermostats) as the 93-96 6.5's were badly under cooled and that leads to most of the cracked head/blown head gasket leaking problems due to overheating in the heads.

 

[WarWagon]

Military IP will be 24 volt. All electronics on the engine will have to be swapped.

Is this a HD truck?

The smoke sounds bad from blowby and possible cracked or hole in a piston. Still possible a pushrod fell off due to a rocker button breaking, but, that doesn't solve the blowby.

 

[Will L.]

If it is an HD truck, being taller body - would he have room to drop in the center mount turbo, then just a little exhaust work to the gm6.

 

[handcannon]

I'm just guessing here, but I don't think there will be any difference in the clearance of the motor to the firewall in the HD truck. As near as I can tell from what I've seen, the big difference with the height of the HD truck over the standard truck is in the suspension. The front axle setup raises the whole frame up in the air more. Then to compensate for the front bumper distance to the ground the front frame is shaped different putting the bumper in a lower plane, which then requires the spacer between the grill and the bumper.

Again, this is not from being able to put the HD and a stock 1500, or 2500 side by side and measuring.

Don

 

[Burning oil]

WW touched on it, is the hummer engine a DB2 (mechanical) injection pump? If yes you'll need to swap in the 94 IP and lines to it.

 

[Husker6.5]

From 19 years in the Army, and a former Maintenance Officer, ALL MILITARY 6.2/6.5's are mechanical injection, I don't know about the civilian Hummer H1's. EMP - battlefield survivability - by NOT having any unnecessary on board electronics/computers. Certainly you'd have to switch from the military alternator set up to the 12V during the switch over. Of course, we were turning up the IP screw on our 6.2 and 6.5 HMMWV's, I remember one run down I-15 when I was at the NTC from Barstow to Victorville in one of the Hummers my mechanics "juiced" staying with traffic at 80+ mph. Damn that canvas top was noisy! WAY back in the day, I remember the maintenance section in the unit I was in at the time working on our Gamma Goats (an articulated 6x6 with a four wheel cab and an attached driven 2 wheeled trailer) and "tuning" the 3-53 Detroit in them so that little monster would rip down the highway at 85 mph! They were the evacuation ambulances for the Medic Section at the Battalion HQ Company in our Mechanized Infantry Brigade, and they would move! LOUD was an understatement when they were wrapped up that tight, the motor sat right behind the driver and co-driver in the cab, and we had to wear over the ear sound protection when driving them.

Anyway, back to his bucket truck. No, the space under the hood on the HD is no different than a '94 pickup so he'd have to convert over to the side mount turbo on the military engine. IMHO, I would NOT attempt a rebuild on the 94 motor if I had a new GEP military motor available to start with as a foundation. It is a much stouter block. I would buy a pair of NEW p/u heads and go from there and drop in the military motor into the 94. MUCH cheaper in the long run, especially if he rebuilds the 94 just to have the main webs crack on it later. Since it would already have the 130 gph water pump on it, he would just need to get a 97+ dual thermostat crossover and then reuse most everything else off the 94 block in the way of manifolds, etc.

 

[Will L.]

Keep in mind you will be able to sell of those unused parts:heads, turbo, manifolds, and turbo pipe parts to offset some of the cost. Start with maybe a deal w/ Handcannon in the wanted to buy section...

I just did a modification using truck heads mounting up van manifolds that I will post as soon as I can figure out posting pics. Maybe you could build a center intake piece to go from the side mount turbo to the 2rail design intake manifolds then you could run those heads if you dont want to get different heads. Just an idea, but keep in mind I'm a nutcase.
Just a piece of flatbar with 2 bolt holes and the factory seal will take care of the oil supply and return holes under the turbo.

 

[bubba]

Keep in mind you will be able to sell of those unused parts:heads, turbo, manifolds, and turbo pipe parts to offset some of the cost. Start with maybe a deal w/ Handcannon in the wanted to buy section...

I just did a modification using truck heads mounting up van manifolds that I will post as soon as I can figure out posting pics. Maybe you could build a center intake piece to go from the side mount turbo to the 2rail design intake manifolds then you could run those heads if you dont want to get different heads. Just an idea, but keep in mind I'm a nutcase.
Just a piece of flatbar with 2 bolt holes and the factory seal will take care of the oil supply and return holes under the turbo.

cool thanks!