Detroit diesel 8v92

1. I would be concerned, but removing the airboxes and looking into the cylinders should tell the tale if everything is ok or not.

2. Look at the condition in the racors and assess it there. How much fuel is on-board? Running it all out along with something like clear-tank diesel from Diesel Kleen, as well as changing filters might be your best bet.

3. I've found that polishing it only takes out 90% of the algae and it tends to spread back like cancer. See #2.

4. I've run detroits a lot at say trolling speeds or 1000 rpms, while not recommended for long long periods of time, I run them up to cruise for 30 minutes every 4-6hours.

5. The 92 series is not considered as durable when it comes to longevity as the 71 series.

6. Run them under a load and often, use the boat at least once a month, start and run them at least every 2 weeks, block heaters to keep humidity out helps but also uses a lot of electricity. Change the oil and filters once a year, coolant every 2 years and raw water pump impellor and belts if equipped. Make sure air cleaners are kept clean also, if equipped.

Thank you VERY much Capt J. I may get a chance to look at this vessel tomorrow. I'll keep your list handy.

Does anyone know what the cost of an overhaul on a 1990 8V92 goes for in the north east?

This might be a cheap way out, with Jake Brakes on it it looks like it has been in an automotive application.

http://www.powerlinecomponents.com/...+PCI&serialnumber=&formspecificserialpublish=

There is no way to remove and replace the engines without cutting the boat in half. I am thinking of an overhaul while it is in the boat.

It depends on many factors and access is one of them. But figure around $35k including rebuilding turbo's, injectors, cleaning all of the heat exchangers etc.

The bottom end parts seem cheap enough: http://dieselrebuildkits.com/k2/die...sel-series-92/detroit-diesel-8v92-rebuild-kit

What sort of boat is it in , do you have one or two engines? Have you looked at removing the saloon sole rather than chainsawing her in half?

The parts are relatively cheap, it's the labor that's expensive. The detroit diesel dealers here charge around $112-116 an hour per mechanic from the moment they leave their shop. Think of how many hours (for 2 guys) and trips to the boat there are when doing an in-frame rebuild.....the bill adds up very quick.

It is a 60' Viking Motoryacht. I checked and there is no way to life the engines out.

You should be able to rebuild them in the yacht if need be.

If he can't remove them he doesn't have much choice does he

And he was already on to that idea, as stated in post #25:

"There is no way to remove and replace the engines without cutting the boat in half. I am thinking of an overhaul while it is in the boat."

There is always a way. Don't stop at one yards opinion. MY's have some extra hardships but going thru the saloon deck and coach roof was the answer on a Southern Cross MY. Did'nt like that headliner anyway.

I'm no mechanic or engineer, so I'll leave all that to you guys who are. What I will add though is that I've run a lot of crew boats, LCMs and such with 8-92's, and Valhalla has 8-92 TI's. With her running since 1981 I don't know how many rebuilds they've had, but they've currently got about 800 hours. We've done about 3900 miles in the last year and a half, and I love them. We had to replace a foward seal last winter and are currenly replacing the oil pan seal, both on the port motor. There's been no smoke and their oil analysis have all been good.

He didn't ask about removing them. He asked how much it would cost to rebuild them. We don't remove engines over here in the States to rebuild them, unless it's super easy to remove them, or you have no other choice (need to line bore etc). I'd say that 97% of the time all overhauls on yachts this size are in-frame majors.

Some comments were made about removal.

I would think if Viking Corp was contacted, pulling options and diagrams (maybe cutting templates) could be obtained.

Throwing in an extra 2 cents;
I rebuilt my 12s in-frame with a saloon roof factory patch already in place. We had already tore down so much in chasing the problems, we continued the in-frame re-assembly.
My ship was already a mess. No concerns of carpeting, trim & finish getting trashed. No worries of bilge odors wifting thru the ship. Strong backs were available to drag heads and logs in and out. Looking back, it was a good job, but I still wish I pulled them. Could have replaced that rear seal much easier on the port engine (still wonder about that stb rear seal).
I do recommend pulling when you can. It's amazing how clean the engine room (and ship) can be when it's all put together.

Circumstances where I've seen a DD rebuild include removal is when a major refit has the rest of the boat all torn up anyway. With an otherwise intact boat they're rebuilt in place.

I just pulled a 12v92 out the back door of a 54 Bertram. If stripped down, it can be done.

It will surprise many just how small you can strip most engines down to if you really need to, the block which is the biggest lump is not that big when all things that bolt on are removed.

I have rebuilt and done major repairs to a few smaller motor boats with the engines still in situ, I much prefer to do big jobs when access is un restricted to the lump as a whole but as with other things in life one has to cope with the hand they are dealt and if it has to be done in situ it will have to be done that way.

And I hope I never have to do that again! Thrust bearing spun out and scored the block. Had to replace half the block. Brand new engine! Other engine has about 2800 hours but no smoke and runs great!