What to do about engines

R

ray306

New Member
Jun 26, 2007
171
Hollywood, Fl
Boat Info
sundancer 350 1990
Engines
502 mpi
We own a 1990 350DA and live in the Ft. Lauderdale area. We purchased it over the summer, had it surveyed and we're quite happy with the boat. We use it a fair amount here in the land of year round boating.

Last week I heard a funny sound coming from the starboard engine, called the mechanic, he says low compression and water in 5 and less than optimum compression in 6. These are carburated gas engines(454's) and have approx. 750 hours on them so it is clear that these engines are probably in the last 1/3 of their lifespan. Since the engines are raw water cooled that is salt water in the cylinder. My quandry is: What to do now.

I'm looking for some insight and/or advice.

Here are the options, as I see them, from lowest cost to highest cost. 1) Have a mechanic do a quick rebuid on only the bad engine ( approx. $4000). 2) Found a used set of 454 engines that supposedly has 200 hours on them.....??but the engines are 1988's??Though they do have fresh water cooling. Mechanic has already started them and checked them out(approx $7000 to do both).3)Have a complete and thorough rebuid; new long block..everything back to factory specs...1 year warranty(approx. $15,000 to do both engines)4) Replace both gas engines with 2 new EFI gas engines(approx $13,000 per engine..should probably do both so $26,000)and finally 5)replace gas engines with a pair of diesels(approx almost $40,000 which does not even take into account the brand new gas genset on the boat)

Now, I am not so much concerned about resale as I tend to keep boats for a long period of time but it is an issue to consider. Our use of the boat is in the intracoastal near Ft. Lauderdale, the Florida keys, runs to the Bahamas, etc.Considerations may be increased speed, range, and fuel efficiency with diesels though maintenance is more expensive. Finally, how much is too much to spend on a 17 year old boat that both the Admiral and I love.

Thanks for your input/advice

Ray
 
I'd be concerned about how water got in there in the first place. You wouldn't want to put brand new engines in and have the same thing happen first time out. And 750 hours are the last 1/3 of their life? I'd always figured around 1,500 - 2,000 hours, but you are right most of the time they die for other reasons like ingesting water or improper maintenance.

Before spending $40,000 on Diesels plus $10,000 for a generator, I think I'd look around for a boat already equipped just to see if it might be easier to trade than repower. You will incur some downtime during prime boating season and $40,000 seems low and is just an estimate. What other gremlins will you incurr like tanks, gauges, wiring, etc,.

Boating never makes sense. You have to determine what makes YOU feel good about the decision you make. I'm sure you could justify any of the options. After all it's only money!
 
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Since you are new to the boat, I would have to favor just doing the top end and see where that leads you...

From the questions you asked, I would say that your thinking you want a new to you boat with newer long life engines so you dont have to miss those all year round days.....

Good luck and Merry Christmas!!!
 
I've been almost exactly where you are with an '88 390EC.....only I never got water in the engines.......and my solution was a 450DA with Caterpillars.

The water almost certainly came from the exhaust system....risers corroded and failed, riser gaskets got brittle and failed or the exhaust manifolds corroded and failed. Rebuilding the top end may solve the mechanical probelm with the engines but you still have to address the leak. With 15 years + and 700 hours on sea water cooled engines this is not the first set of risers and manifilds its had. To do this right you are looking at replacing all the exhaust system castings, the circulating pump, thermostat housing, thermostat, timing covers (Mercruiser paints the engines after assembly and the center of the timing cover is bare metal and is rusty, so now is the time to fix it too.) Figure about $4000 for all that in addition to your rebuild cost.

But, the bad news is your mechanic is more than likely going to discover that the engines cannot be rebuilt because the blocks are full of rust and corrosion sediment. Even vatting a motor will not remove rust particles in the skirts of the engine blocks. As it builds up the engine gradually loses its ability to cool since the block sirt is pretty much a solid mass with the corrosion build up.

Used engine bear some risk, but if they were FWC, you shouldn't have the corrosion build up problem. You will need to add FWC if you plan to keep the boat, or face a do-over in about 5 years.

One more bit of bad news is that your guess at repowering with diesels is very low. This isn't just a change in engines or the cost of 2 diesel motors. You will probably need new transmissions to get counter rotation and to withstand the additiional torque, and to handle the lower rpms, you will need new shafts.....1 1/4" are too small for diesel torque, new props because of added torque and lower rpms, a new generator since you don't want a diesel boat with a gas generator, a new fuel system plumbing to accomodate the fuel return system on diesels, depending upon what diesels you select, you may need larger sea water intake grates,sea cock and strainers. Probably the lowest cost approach to this is to use Yanmars which are higher rpm diesels and are smaller and a little easier to fit in than other makes. Even so, the cost is going to be closer to $70K than to $40K.

In my case, I decided that investing an additional $60K in a $100K boat ( at the time) to end up with a $125K boat made a lot less sense than selling the 390 and replacing her with a later model diesel boat.......although we loved the 390 and would still own her if she had been diesel powered. If you think this thru, you will probably come to the same conclusion on the 350DA. And, that may answer your final question......if your total investment gets you well past the replacement cost (relative worth on today's market) of the boat, then consider upgrading to a later diesel powered boat. There are a couple of diesel late 90's 370DA's on the market in your area for under $160K.
 
The first year or so of boating is a real learning experience, and your interest and priorities will likely change. Also, on that age boat, you will need a slush fund for other system repairs & upgrades. I suggest rebuilding the damaged engine, and checking the other for signs of a similar problem developing. That will give you time to see how much of your expectations are practical, and if this is the best boat to persue them.
 
Frank's answer came in while I was typing, and he makes a lot of sense. It's always a bummer to buy a used boat and run into serious maintenance bills before you get much use out of it. Your initial problem could be a sign of unending future repair work ahead, and a fresh start might be the best move now. However, one reason that I favor a moderate repair is that it gets you right back on the water so you can continue exploring your interests and capabilities. You also can see what other boaters have, and what they are doing that may interest you. That might shape your choice of the next boat.
 
Ray,

I agree with pretty much all of what's been said. In the end, of course, the decision is yours.

Frank is completely correct in saying that the blocks are probably not rebuildable because of being raw water motors that are now 18 years old. I've seen this with several trailered go-fast boats locally that weren't religiously flushed after every run. When cooled with raw water the motors become disposable. You won't get a credit for a core charge if you go to remanufactured blocks.

The thought that you might just do the heads on the offending motor is a good one, but be prepared that they might also be too far gone to rebuild, though buying a good used set to do a valve job on will still be a big savings over a complete long block.

If you decide to replace one or both motors with rebuilt ones, here's a very good builder-

http://rebuilt-auto-engines.com/

Don't let the name fool you. They will do a marine 7.4. They automatically do an upgrade to hyperutetic pistons (the originals are cast), install the exact cam profile, and give a full one year warranty for marine use. EVERYTHING is new except the cast iron pieces, the block, crank (not ground more than .010" undersize), rods, and heads. I bought mine from them, and am very impressed. The are top notch professionals. Cost per motor is $1782 plus $500 for the core for the standard (port) side, and $1882 plus $500 for the reverse (stbd) side, plus shipping. You can trust these folks.

I wouldn't do just one motor, as you'll want to add fresh water cooling to both. You won't get all of your money back at resale, but keep all of your reciepts and you will recover some of it, and have peace of mind for the year or two (or more) that you use the boat. It's hard to sell a boat these days anyway, let alone sell one with original raw water motors.

Just my 2 cents, as they say. Good luck- this is not the end of the world, just an opportunity to know what you have and feel good about it.
 
Once additional thought, please.

Mercruiser manifolds are notoriously bad about allowing water ingestion. Crusader is far better, but Brunswick owns both Sea Ray and Mercury so that's what we get.

I have a good friend who replaces the riser gaskets on his motors ('89 340DA) every season, something we should all do. He's never had a water ingestion problem, because he can see the condition of the manifolds before he has one. Before he puts the new gaskets in, he takes at least his risers to a local machinist and has them cut for a fresh gasket surface. The manifolds and risers last 5 - 7 years doing this, which is time to change them anyway. This is a very good habit to develop.
 
That riser to manifold gasket is a known weak area. Mercruiser has has about 20 parts revisions on the one for the 340hp 7.4. As a general rule of thumb, begin checking the risers at 3 years of use and then annually thereafter, until you replace them. The gasket is a thin paper or cardboard style gasket and ovet time it cooks and gets brittle and eventially fails.

Spending $10 and an hour's labor to replace the riser gaskets (checking the risers at that point is free) seems to me to be a cheap way to avoid a total engine loss.
 
Thanks everyone for your input.

One additional piece of info that I neglected to include was that the risers, manifolds, sea water pump have all been replaced in the last 3 months. It was one of the first things i did after purchase.

Ray
 
Ray,

Can your mechanic shed some light on where the salt water came from in the #5 cylinder if the manifolds and risers have been recently replaced?

-John
 
What would be the technical/'nuts & bolts' solution if the decision is to move on rather than a bilge up re-power? I am not suggesting a blueprint for a 'duct tape and bondo rust repair' kind of thing, just the minimum needed to get the engine into a saleable condition.

I guess the real question is how much of the repair cost is needed to make the engine run without a dead cylinder, and how much is 'while it's a part' and 'I don't want to be doing this next year' logic?

If it turns out that all is needed, is the better strategy to do nothing, advertise as is and let potential buyers decide for themselves, or fix it?

I recognize there are ethical issues, as well as potential local regulations (lemon law type things) that influence this as well, but let's set those aside and just address how to fix situation.

Henry
 
To try to get a good feel again for your personality, I just read your initial post again. You mention that you typically keep a boat for several years, and that both you and your wife love the boat, so let's assume that the size and layout of it fit the bill nicely.

Following up on Henry's post then, how do you approach repair or replacement of your motor (s)? Where do you stop once you're in?

Using the numbers from my earlier post, a pair of well remanufactured long blocks will come to something under $5k, plus shipping. You already have spent the money on manifolds and risers, which is not small chunk of change, so you'll reuse them, of course. If you are this far already in deciding to do a longer term fix, belts and hoses would be a good idea, and you'll have all the tune up parts to buy as well.

Your boatyard will burn up a lot of time removing the motors, disassembling the old blocks, cleaning up the parts that you'll need to put back on the new long blocks, and reassembling it all when done.

Roughly, I'd guess that you could put everything together well for less than half the cost of brand new motors and transmissions, whether you're looking at Mercruisers or Crusaders. Remember that with new you'll need the down angle transmissions becuase that is where the reverse rotation is done on the new motors, so just the motors and trans are about $16k each.

Remember too that if you decide to patch that one engine together, sell the boat, and find another, unless you buy new, you will still end up with a used boat and drivetrain. A good mechanical survey can give you a very good idea of it's condition, but used is used.

You might find that the peace of mind in having everything fresh at once is well worth it. And you'll always know what you have, when it was serviced, and how it was run. This has to add to the enjoyment of your boating experience.

Your 1990 350DA has seen most of the depreciation it will have. From here it should be worth about the same for the next several years, provided it's kept in good condition. If you buy something newer, it could easily depreciate as much or more than the $15k - $20k you might spend repowering.

No matter how you shake it, boats are not cheap, and not an investment in any way. Whatever you do, find a way to use it, otherwise it truely is a waste of money. If you love it, it's the best money you can spend.
 
I guess I'll try one more time on this thread. Isn't it a prudent thing to figure out what went wrong in the first place? He has a mechanic who said salt water was present in the number 5 cylinder. How did it get there if the manifolds/risers/elbows were PROPERLY replaced a few months ago?

It would seem that IF the ingestion is related to the work that was done a few months ago, the solution is pretty academic.....somebody else pays for the repair.

I would agree that if it is unrelated (which somebody would have to prove with a blown head gasket, cracked head or block) then a lot of the thoughtful content in the thread applies.

-John
 
this thread is worth a read.

http://clubsearay.com/forum/showthread.php?t=5473

i posed the question hypothetically and here you are, facing the dilemma for real. if you love the boat, plan on keeping it and can afford it, i'd go diesel. that's just me. if not, i'd go the next most expensive thing - new engines. ingestion is not likely to be the cause of this problem as you dont have underwater exhausts. to be honest, i'm not sure WHAT could have caused this problem in light of the fact that these engines had MAJOR work done recently. maybe the mannys were so bad when your mechanic took them off that he had to use a sledge hammer to dislodge them - thus he couldnt really do a good post-mortem on them. i dont know. but that is a real shame that you spent all that dough for nothing.

which calls to mind another option, if it's possible...new blocks, recycle your recently installed stuff on the new blocks (if you can buy them w/o manifolds and risers). not sure if that's possible.

maybe markd could help out on this thread, as he had a similar problem a couple of years ago on almost the same boat with almost the same number of hours (his boat was FWC).
 
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woah. . .I missed the part about new risers and manifolds.

Reread what Playdate said very carefully. . . . something is not right here. You replace risers and manifolds to PREVENT this from happening. But if you don't do it right. . .guess what happens next?

Where is this water coming from??
Ask your mechanic very specifically. Then get another mechanic to verify what was said. You may not only need a new engine, but you may SERIOUSLY need a new mechanic.

My mechanic made a mistake with some work this summer. . . . . . he took pains to make it right at no further cost to me (except for a haulout by a third party). I am continuing to use him for work.
 
Playdate:
I guess I'll try one more time on this thread. Isn't it a prudent thing to figure out what went wrong in the first place? He has a mechanic who said salt water was present in the number 5 cylinder.
Click to expand...

I've read your posts but unfortunately, with my mechanic on vacation untill after New Years Day, I'll have to wait until then to get more info.

Thanks everyone for the help.

At this point I'm leaning toward new gas engines. The best solution is diesel but it would appear that my initial estimate is way low; I just can't justify that kind of expenditure

Ray
 
I dont want to hijack this thread but Ron asked me to chime in here.... and yes, I had/have similar problems but mine was FWC... Meaning only the Risers & coolers see the raw water, not the manifolds.... I actually did my own risers/coolers etc. on my boat to be proactive too. A few years after doing all this work I had a hard start problem on the port engine at spring commissioning. The mechanic found that I had a stuck valve on the #6 cylinder. Again, being proactive, I asked him to rebuild the heads etc etc etc. Move forward 6 months, I had left the marina where I had the work done and headed 140 miles north to a different marina. I layed up the boat for winter and changed the oil & found water in the oil. Nice huh?!? I found a leaky riser gasket on the port engine....just like others have said always being a problem. Problem was, the tech who worked on the heads/riser installed them like a freaking king kong gorilla!!! No where near the proper torque spec. It was all i could do to remove the bolts! This caused the gasket to fail.... unfortunately, I was too far away to bring it back to the mechanic. I replaced both gaskets and hoped it held. It seemed to work for ~1 year, now I too am seeing signs of water intrusion again in the oil. I would imagine either:

1) The same gorilla over/under tightened the head bolts & I just didnt see anything abnormal right away.
2) The riser gaskets have failed again. They seem fine though with no outward signs of leakage.

I did run a series of compression tests on mine and all the cylinders seemed to be within 10-15% of one another. I plan to have an oil analysis thru Blackstone Labs completed to determine what the cause was....

Bottom line - Playdate is right. This most likely was due to the recent work you had done. My rationale is that this was a new (to you) boat & you mentioned you had a survey done with oil analysis (hopefully) and it checked out clean prior. Rondds indicated that the mechanic could have pounded the manifolds off with a hammer or something like that. I couldnt agree more! These things get welded to the metal and need some persuasion to get off. Especially with RAW water cooling. Bolts can break and need to be heated to get
out.... you can only imagine what they do to move the work along expeditiously. Maybe even warped the heads. I would guess that you have a small head gasket leak or stuck valves... Either will show up as low compression. Not sure if you said they removed the heads already.

If it were my boat I would either go for the rebuild or remanufactured engines. Actually, strike that, you have Raw water. Go for a reman'd engine. The raw water will have deteriorated the block unless it was kept in fresh water. Even then.... I dont drive enough hours to have a new engine installed. I have 750 hours on mine now. When I purchased it, there was 350. The last 3 years have seen maybe 40 hours total on th engines. If you use the boat alot, it might pay to get new ones.... not sure about your monetary situation and how much you have to throw into the floating money pit ;) Diesel is always an option, but as Frank said, you'd be alot lighter in the purse and have alot of aggrivation to deal with replacing/fitting the right parts into the boat. Plus, these boats really arent worth that kind of $$$$.

No matter what happens I would be interested in knowing what you decide to do....
 
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