1985 DD 6V92 TA turbo modification question

[saltshaker]

When the exhaust manifolds develop and internal leak, can cooling water leak back into aft cylinders as it can in naturals?? That's a significant advantage in my mind for the standard DD "hot" turbo approach. If so it's enough to turn this configuration to a negative for me.

My 6V92TA's Have the single wet turbos and the water cooled exhaust manifolds. According to my mechanic, they are heavier and much more expensive than the standard exhaust manifolds. An internal leak can take out a cylinder. Unfortunately I know this because my port engine is apart right now due to a bent connecting rod and bad #6 cylinder. We thought coolant got into the cylinder from a cracked head but the head seems fine. Mechanic suspects the exhaust manifold is the culprit. I'll know more next week after he checks everything out.

[Brian Degulis]

Check that very carefully. The manifolds almost never fail unless they've been cracked from freezing. If you look at the configuration you can see that the design and shape of the manifold makes it hard to get water in a cylinder even if there is a crack. You've got a short port that tilts slightly down with no water jacket around it then the tubular section is jacketed. So you would have to have a leak in the tubular section and the water would have to almost go up hill to get in a cylinder (assuming the water entered the cylinder while the engine was sitting) That's not likely.

If it is a leak in the echaust system it's probably higher like your water cooled turbo or connecting pieces.

Unless you find an obvious echaust leak I would really check the heads (magnaflux) and the compression seal rings and other head seals and liners if it's a 92 series.

Brian

Brian

[captddis]

The forward plan manifolds are different and have coolant all around the ports. They have been known to crack.

[saltshaker]

Spoke to the mechanic today and he said the head is good. He is checking the manifold since they are the water cooled ones. They have coolant around the exhaust ports and will leak into a cylinder if cracked. He is also checking the rest of the exhaust components with a small camera. I'm waiting for a complete evaluation of the engine but he said it looks to be in great shape otherwise. I'm wondering if I should do more than just fix the one hole since the engine needs to be jacked up to drop the pan. Seems like now is the time for a major but does it make sense to do it on an engine that has run well and checks out OK? Engine has around 1000 hrs SMOH with a new long block, 8 years ago.

[34Hatt]

Spoke to the mechanic today and he said the head is good. He is checking the manifold since they are the water cooled ones. They have coolant around the exhaust ports and will leak into a cylinder if cracked. He is also checking the rest of the exhaust components with a small camera. I'm waiting for a complete evaluation of the engine but he said it looks to be in great shape otherwise. I'm wondering if I should do more than just fix the one hole since the engine needs to be jacked up to drop the pan. Seems like now is the time for a major but does it make sense to do it on an engine that has run well and checks out OK? Engine has around 1000 hrs SMOH with a new long block, 8 years ago.

So Jack

What was the out come of your motor??

[saltshaker]

Only thing faulty was the head gasket. Insurance company sent it to a lab to have it analyzed and determined it was defective, no signs of an overheat or poor installation. They paid for all new cylinder kits, new turbo head for the outboard bank and most of the labor associated with rebuilding the engine. I'm paying for the inboard head, injectors and a few other things.

Unfortunately, we've had a problem getting parts. My mechanic had a hard time getting 6 matching Detroit kits. We had to wait almost 3 weeks for the sixth kit and are still waiting for the turbo. Not a big deal for me as I have been swamped with work and the season has been over for us here in NJ. Hoping all is finished by the end of next week so I can get in one last run before I put her away for the winter.