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.
--------------------------------------------------
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!

 

[MikeP]

I would thank the mechanic for his advice and put better air filters on there than oem...especially after spending a bunch of money on rebulids. If you have the old oem filters - big cans with some foam covers that usually don't actually cover the entire perforated area of the can - they are essentially NOT filtering the air at all.

These engines pass a lot of air and any dust or other particles act just like grit on those newly installed piston rings and cyl walls. There is no such thing as intake air that is too clean. K&Ns will cost you about $45 each which is insignificant in the scheme of things!

 

[Tawney1]

Thanks Mike and guys. I have decided to go with Racor CCVs. There appears to be too many questions/issues with Airseps.

The port engine is now about 80% reassembled. I wanted to chrome the valve covers but cannot find anyone to do it. Oh well.

I have a question about the starter(s) and alternator(s). They are not being rebuilt and they have not run diagnostics on them.

We had no problems with them at all to my knowledge. However, I am wondering whether I should have them checked now and/or just bit the bullet and get rebuilt.

Also, our batteries are now 4 years old. I would like to go back with something that takes up less room and weigh less, if possible. Any suggestions or advice?

Advice from you guys about the starter(s)/alternator(s) and replacement batteries will be appreciated. Anything else I should be concerned about?

Thanks,

Paul

 

[Brian Degulis]

I would like to see a photo of the guy who's laying under one of them to do the bottom end. I keep looking at mine and I'm just not seeing how that's possible.

Brian

 

[StratPlan61]

Brian, I second your thoughts. On my boat, it would have to be a thin, short mechanic with 18" arms????? And then, what could he measure or see, much less tighten crankshaft mains. Plastigage in one hand and a torque wrench in the other?????? Hmmm . . . . . .
I want to believe, but a picture would convince me.

 

[hattitude]

I have a question about the starter(s) and alternator(s). They are not being rebuilt and they have not run diagnostics on them.

We had no problems with them at all to my knowledge. However, I am wondering whether I should have them checked now and/or just bit the bullet and get rebuilt.

We have a local shop that rebuilds alternators and starters. The do an excellent job. You can bring them a starter/alternator and they will bench test it and tell you if it's up to spec...//

See if there is a similar shop in your area and have them check them out......

 

[Brian Degulis]

Brian, I second your thoughts. On my boat, it would have to be a thin, short mechanic with 18" arms????? And then, what could he measure or see, much less tighten crankshaft mains. Plastigage in one hand and a torque wrench in the other?????? Hmmm . . . . . .
I want to believe, but a picture would convince me.

Yeah after he mentioned that they weren't going to lift up or turn them I took a second look at mine thinking that maybe when it was striped down a bit it might be do able. And it might be but I'm just not seeing it mostly because of the containment area it's just to short and closed for and aft so I just got to see it.

Brian

 

[Tawney1]

Well guys, when I was first told they would not need to raise the block I was skeptical too. But -- break down an engine, remove the exhaust manifolds and the oil pan, and crawl under. lol. It is true -- at least on our 61'.

I actually saw the mechanic lying on his back and side in the bilge under the engine -- working. Of course, there was another mechanic there topside helping him.

I am 5'9", just under 175 lbs. -- the mechanic is about my size, maybe a tad or so shorter.... While checking out their work and just looking, I personally did not get completely under the engine --did not see the need to do so. But I can tell you that had I been so inclined, it would not have been a real problem.

I will try to get photos when they do the starboard engine.

 

[Genesis]

There ain't a snowball's chance in hell you could have done that on Gigabite

Must be nice to have a 61.....