rebuilding our 12-71s - photos

[Tawney1]

Well..., Covington Diesel (Wilmington) began rebuilding Miss Mary Alma's 12-71s a couple of weeks ago. The port engine has been broken down and the rebuild/reassembly on it is about 60% complete as of today. The camshaft on the port engine was bad, so it will have to be replaced. Other than additonal costs, the other problem there was that it could not be completely removed from the engine block because of the bulkhead in the engine room. As a result..., we had to cut a hole in the bulkhead..., which will necessitate repair and new veneer on the rear wall in the VIP stateroom. $$$

Yes, we saved the removed pieces of bulkhead to glue back in, but it is no longer a solid wall.

Also, no A-frame was built to raise and turn the block, as after the removal of the oil pan there was enough room for a guy to actually get completely under the block.

As requested earlier when all of you helped me with comments and suggestions on the rebuild, I am attaching pics.

Any "while you're in there"s I should consider other than engine room detail after the job is done? Are there water systems smaller than the monster that's now in there?

Also, the mechanic is telling me not to buy Airseps. Something about negative pressure.

Thanks,

Paul

[Tawney1]

More pics.

[Tawney1]

More pics of the rebuild.

[Brian Degulis]

Hi I've got the same boat as you. Are they doing the bottom end without lifting the engine? If so I'm wondering how that's possable looking at mine I wouldn't think there's enough room for anyone to get under it and work on it?

Brian

[Will]

Tawney1

What does you rmechanic say about RACOR CCVs in lieu of the AirSeps?
Will

[MikeP]

Someone was actually able to get under there? Wow! That's a good thing of course, since it's the only way the bearing clearance can be checked.

Re AirSeps/CCVs the consensus (there are lots of posts here and on Boat diesel on this subject) is that the air seps are a poor design and better performance will be gained by using a CCV on each engine and a K&N or similar filter on the intakes.

Here's a pic of a CCV and K&Ns on our puny 8v71s!

[Tawney1]

Hey guys, yes, after they removed the oil pan, the mechanic was actually able to get under the engine. Actually, sans oil pan, there's a lot of room under there.

I did ask about both air sep and racor. The lead mechanic suggested saving my money and staying with factory OEM air intakes..., with the comment..., "just keep 'em clean."

[jim rosenthal]

Any advice on this? AirSeps seem generally to be in poor repute these days; the concensus seems to be to get CCVs and just drain them frequently. The "savings" in maintenance one gets from having a system that supposedly recycles oil into the crankcase (which I don't believe actually happens) seems offset by the material fact of blowing dirty material into the intake of tthe turbo. Great idea in theory, lousy in practice- I'd rather have CCvs, and just empty the oil out now and then so I know where it's going. As opposed to not being sure.

[Passages]

Let's see what the consensus on Racor vs AirSep really is with the new poll function. I'll set it up and we'll let the experts weigh in.
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OK, I just learned something - Polls can only be attached to the first post of a thread. I'll set up a poll in this category.

Here is the link:
http://www.samsmarine.com/forums/showthread.php?t=7112

[Tawney1]

Good deal! I'll then take the results to Covington Diesel's lead marine mechanic and get his reaction/input!