New engine for the family truckster!

[njsteve]

I just splurged $8 grand+ and bought a brand new engine from the military HUMVEE assembly line at AM/GEP (via Peninsular Diesel, who have a contract with them).

It's the upgraded 6.5. Not the Optimizer that GM sells over the counter...or used to as they recently discontinued the exact engine for my 1995 model but still offer the other years. This is the 2017 higher-er output military version with super heavy duty block, forged crank, rods, low compression (18 to 1 anodized, instead of 22 to 1 standard pistons) and upgraded cylinder heads. The lower compression pistons allow for much higher boost without causing much higher internal heat and strain.

I bought this 1995 GMC K2500 diesel Suburban brand new back in the Spring of '95. You may recall the fun I had when the headgaskets blew during the MCACN trip in 2013. The headgasket replacement lasted another three years and 15,000 miles but the recent oil analysis was showing some major lead and tin values in the oil - to the tune of 17 times the maximum recommended standard. Every time I'd talk to the oil analysis techs, they kept asking if this was from a running engine or an autopsy? When I told them it was running fine they asked if it had any oil pressure and whether it was making angry, loud, unnatural noises? In fact it has been sounding the same way for the past 22 years and has never been stronger!

And you know as well as I do that a great running engine is always a bad sign that catastrophe is just around the corner. I even towed the SD455 and 24' trailer with it last weekend and it ran flawlessly.

So obviously it was time to go big or stay home.



Here's the oil analysis:

[njsteve]

And here's the new engine. All 875 lbs on the stand.

[njsteve]

Here's the build thread over on the diesel website I hang out at. There is something of a cult following for guys who try to keep this 6.5 diesels on the road.

http://www.dieselplace.com/forum/63-...camper-20.html

And yes, it's a Real Turbo-jet 396. :-)

[Xplantdad]

Cool!

[Tarrytown SS427s]

Nice old Suburban, and looks like you've kept it clean! I always wished they put the 6.6 into the GMT800 Suburbans.

[Tommy]

Originally Posted by njsteve

Here's the build thread over on the diesel website I hang out at. There is something of a cult following for guys who try to keep this 6.5 diesels on the road.


And yes, it's a Real Turbo-jet 396. :-)

6.5 owners like pain and punishment, I'm one too.. Just threw 3000 bucks at mine (again)...

Tommy

[njsteve]

What did it need? I've been tinkering with this one for over two decades now. Other than the headgasket glitch (a known problem) and relocating the PMD (injection pump brain) to behind the front bumper instead of on the 200+ degree engine, it has been a great truck.

I decided against rebuilding the existing engine because it already has the inherent stress cracks in the original heads between the valve seats (which GM declared to be not an issue in their TSBs), so I would have had to spend a couple thousand for some non-Chinese cast heads... and then new pistons for a thousand more...yada yada - til the cost approached a brand new engine that has all the old weaknesses designed out. That's not even considering that possibility that the block could have main web cracks. Certain batches of these blocks, mainly in the 1997 to 2000 range were machined too quickly after casting and were too green when assembled. The main webs crack right were the bolts go in and travel to the location where the oil squirters were drilled to spray the bottoms of the pistons.

So, in the event the block has no cracks, I already have several 6.5 guys wanting it.

[Tommy]

I had new injectors/glowplugs and glow plug relay installed as well as new Turbo and turbo master from Heaths Diesel (with hurricane wheel). Also bought Heaths improved water pump and new fan. I ditched the old crossover pipe and added the larger mandrel bent unit as well as a Diamond eye 4" exhaust. We found several oil leaks and spent some time and money sealing those up. Added a new starter from Heaths too and had to buy a new front starter brace as the last one was installed without the brace. last year I trashed the 4L80E so that was replaced with a new one.

My truck is a Behemoth, a 2000 model long wheel base crew cab 4wd dually with 4:10's and I was hooked the day i saw it. Unfortunately I was never a fan of the engine but the rest of the truck overrulled the engine. In case anyone is scratching their head, yes its a 2000 model. the 2500/3500 kept the 88-98 body till 2000.

Tommy

[njsteve]

You will like that Diamondeye exhaust and crossover. That was my Christmas present two years ago. The 6.5s really breathe with that setup. That factory crossover pipe is a horrible double wall design and 50% of them have a collapsed inner pipe at the bends. It reduces the flow from a 2" pipe to a 1/2" pipe.

I've been running the Heath maxi-torque chip and turbomaster manual boost adjuster for 6 years. My truck is an OBD1 so it uses the old fashioned PROM chip. Good stuff. I also have a delegated laptop that has the GMTD Scantech software on it so I can reset the pump when I install it on the new engine. Without that you have to go to the dealer and they usually had no idea whatsoever on how to work on these trucks (unless you find an oldtimer still working there) .

Never run a starter without a brace on these engines. Many a horror story of guys breaking the ear off the block from the starter loosening the two mounting bolts and then torqueing over without the brace in place.

Let's see a photo! My neighbor down the street has the exact same truck (but a 454) and it's black. Evil looking monster.

My first casualty so far has been the starter - the tiny terminal on the solenoid snapped off...and get this...the AC/Delco solenoid is discontinued and even an aftermarket version is $165!!!! But a brand new ACDelco (not reman) starter is $148 (rockauto). Ordered it yesterday.

[njsteve]

Oh, the joys of getting those last two upper bellhousing to engine bolts. There is no easy way to do it. They are double studs with all sorts of brackets coming off the studs. And not accessible from under the truck. I had to rip the remainder of the inch-thick, sound deadener pads (probably made of asbestos) off the firewall to even see the studs. That, of course is after I pulled the intake manifold, fuel/water separator, assorted non-moveable wiring harnesses, etc,. Luckily I borrowed my friend's ladder-creeper - a real life saver! I used a ratcheting, angled, closed end, 1/2" wrench for the nuts and 9/16" for the studs. - yeah this is a 1995 so they used SAE threaded transmission-to-engine bolts. Everything else on the engine is metric.