Exhaust Manifold Replacement

[Ron B]

I would appreciate any comments on the number of hours of labor involved for a qualified diesel mechanic to remove and replace both exhaust manifolds on a DD 8V92TI. I am having it done on my 56' Hatteras. Thanks

Ron B

[Boatsb]

How is the access. Are any bolts going to break off and need to be drilled out? Is anything else going to be a problem? Has your mechanic given you an unrealistic estimate ?

[Canuck Dennis]

I have a stand up e/r and can replace a manifold on one of my V12's in under 2 hrs real easily. I would be surprised if not less than a days work provided access ok and no other unusual obstacles.

[dsharp]

It's almost impossible to answer that question without seeing the engines and engine room. You can spend a considerable amount of time with corroded fasteners. I would start spraying them ahead of time with penetrating oil.

[MikeP]

Totally agree that it could be anything from a cakewalk to a nightmare based on access and the state of the pertinent fittings; one broken stud/bolt at block-level can turn it from "This is going really well" to "Oh $h1t!"

Quoting a fixed time/price can be difficult for such stuff simply because of the possibility of seized/broken fasteners that could easily double the time needed.

I have seen one broken fastener take a 1 hour manifold change (car) and turn into and all day deal: Seized manifold bolt broke off at the block, mech drilled remaining bolt to insert easy-out, easy-out (hardened steel) broke at the same level...lordy, Lordy, LORDY...

The ONLY foolproof way to remove seized fittings is with heat; the "flame wrench" is your best friend!

[GJH]

56MY is full stand up with lots of room outboard of engines, inboard is a little trickier though there are removable panels in the companion way and good access fore, especially, and aft within the ER. So access is as good as it gets overall. The real issue as noted is if the bolts are seized. Get references on a good mechanic familiar with the engines. Where are you Ron?

edit, I should not that when the companionway panels are removed, the exhaust manifold is right there.

[RT46]

just curious, why do u need to replace them?

They seem to last forever and don't have any raw water in them like gas engines.