Cracked block- might as well upgrade.

[ppillard]

1997 M1078. While replacing my oil pan gasket, I discovered 2 hairline cracks in my block, consistent with death by driveline vibration (which I have been wrestling with on this truck)

Drivelines were balanced and replaced last year, and I’ve been repairing the collateral damage ever since.

Curious: who has upgraded to maybe a 3116 from an A1 or even a C7. Is a 3306 an option? Are you pleased or discouraged?
I’m not interested in non-Cat swaps.

I’d love some more horse power, and I have 3.07 gears sitting in the garage, so I fantasize about doing 70 mph on the highway.

 

[simp5782]

Grind the cracks out and weld them up with nickel rods I've had to do it to a few 3126s. Still holding for years later.

3306 is pretty much indestructible but it is a 10L vs the 7 liters

 

[Ohiobenz]

I've got a 3116 block you can have cheap

 

[fuzzytoaster]

Upgrading to a 3126 or C7 would require rewiring the truck so best stick to the 3116 by finding a 290 hp take out or follow simp's advice to keep it going longer.

 

[simp5782]

I've got a few 3116 take out engines as well.

 

[Lothar]

You're not to far from me. I could help with the welding possibly on a weekend. Got a mobile weld truck and need to get up to my house in Buffalo Creek soon anyway. Think I even have the nickel rod up there.

 

[Lothar]

Duplicate post

 

[ppillard]

You're not to far from me. I could help with the welding possibly on a weekend. Got a mobile weld truck and need to get up to my house in Buffalo Creek soon anyway. Think I even have the nickel rod up there.

Lothar, I sent you my phone number. Thanks.

 

[Lothar]

Lothar, I sent you my phone number. Thanks.

Called and replied

 

[dmetalmiki]

I've got a 3116 block you can have cheap

Ha!, But..As said previously,
Grind the cracks out and weld them up with nickel rods I've had to do it to a few 3126s. Still holding for years later.

3306 is pretty much indestructible but it is a 10L vs the 7 liters

 

[dmetalmiki]

Seems like there are too many Death By's On modern military trucks.
Just a thought...

 

[tennmogger]

Before you trash that engine and go to the effort to replace it, take the pan off and magnaflux the block, looking on the inside. I have seen micro cracks on 3116 blocks that do not pass through to the inside. They were aligned with pan bolts, where the holes in the block apparently built some stress. If you are losing oil, it could be simply a pan seal leak. I had one that only could be sealed with no gasket, and Permatex Right Stuff, an excellent sealer.

The vibration of the engine makes sealing the pans a real challenge. One trick is to replace a bolt on each end with a piece of threaded rod to act as a guide for seating the pan so the fresh sealant does not get 'sheared' by sliding the pan around trying to seat it. (be sure to use metric threaded rod!)

Driveline vibrations probably gets the blame for bad paint too, every malady is blamed on that!!

 

[Lothar]

*Update* this truck is back in service! Little bit of grinding, welding, trip to the weld supply store, some more grinding and welding. Crack went all the way through but by working together, one man heating and peening while other man welds, it was a successful repair.

 

[Lothar]

.