Texas Deep Freeze = Cracked...something on 2016 Mercury 4.5L Alpha

I'd take to reviewing Craigslist "Boats" and "Boat Parts" every morning for ideas.
 
Check with some shops outside of your area.

It may be worth a six hour drive to save $3,000-$4,000 on a repair. Try expanding your net if your shop wants a premium.
 
Set up an Ebay search. Here's a used 5.0 L delivered for $4500. If it overrevs with your gears, reprop. https://www.ebay.com/itm/Mercruiser-898-305-Complete-Engine-V8/353160757070?_trkparms=aid=1110006&algo=HOMESPLICE.SIM&ao=1&asc=20201210111314&meid=cda14fbfb1f9458b9c0e93666d559b20&pid=101195&rk=3&rkt=12&mehot=pf&sd=353432374180&itm=353160757070&pmt=0&noa=1&pg=2047675&algv=DefaultOrganic&brand=MerCruiser&_trksid=p2047675.c101195.m1851
Talk with a performance shop about a 383 stroker. In the day, that seemed to be the ultimate small block marine conversion. V-6s are a stupid entry level economy idea anyway.

Where do babies come from? Chev needed a V-6 in the late 80s so they lopped 2 cyl off their small block 90 degree V-8 on the production line. Unfortunately, a 90 degree V-6 is inherently unbalanced so Chev added complicated balance shafts which worked in its trucks. I bought one of those small Tahoes and liked its power based on a 2-stage induction manifold that reconfigured as rpm went up. MB later tried the balance shaft route (along with circumcision based false advertising) but their shafts failed resulting in another class action. Anyway the shafts and the cool manifold did not transition into the Mercruiser adaptation which means the 4.3 is rough. The 4.5 is the same width so I assume it is also 90 degrees and unbalanced although the fancy heads give it some power.
 
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Question remains, do the motor mounts work? How about the flywheel cover and how it bolts to the transom assembly? If old doesn't bolt up to new that could make for a lot of work.
 
I would do my research and determine which V-8 would fit with minimum modifications. Then I would define the eBay search to focus on those engines and wait if none were immediately available. I would also query the present sellers of engines and let them know what I wanted and was willing to pay. The 5.0 was offered as an example. Waiting for another 4.5 would be an approach. I've set up searches that are still turning up unneeded gadgets after 10 years as I never got around to cancelling.
 
douglee25 said:
I don't know what kind of space you have, but I could complete the work here in my shop at a reasonable rate. I'll also give you a discount if you help and want to learn. I'm located in North Dallas. Let me know.
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Thank you for that. I have a few more days until the insurance company finishes doing their thing. In the meantime, I've started looking at engines and happened to come across a price list for 2021 4.5 engines. According to https://www.proboats.com/mercruiser-2020-engine-prices/, I could just buy a replacement engine for $8,220 (plus shipping). Or heck, I could go ahead and upgrade to a 250HP with fresh water cooling for ~$10,500.

The cost of buying a full replacement engine is about the cost of replacement parts? What am I missing? Presuming I stick with this engine, why shouldn't I just buy replacement engine instead and drop it in with the help of a shop instead of repairing the existing one?
 
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Marcus Matos said:
Thank you for that. I have a few more days until the insurance company finishes doing their thing. In the meantime, I've started looking at engines and happened to come across a price list for 2021 4.5 engines. According to https://www.proboats.com/mercruiser-2020-engine-prices/, I could just buy a replacement engine for $8,220 (plus shipping). Or heck, I could go ahead and upgrade to a 250HP with fresh water cooling for ~$10,500.

The cost of buying a full replacement engine is about the cost of replacement parts? What am I missing? Presuming I stick with this engine, why shouldn't I just buy replacement engine instead and drop it in with the help of a shop instead of repairing the existing one?
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I’d go with the replacement engine, the 3200 goes a long way toward install. Freshwater cooling is over rated anyway. Puddle pilots will tell you different. They don’t even put salt on fries.
 
Marcus Matos said:
Thank you for that. I have a few more days until the insurance company finishes doing their thing. In the meantime, I've started looking at engines and happened to come across a price list for 2021 4.5 engines. According to https://www.proboats.com/mercruiser-2020-engine-prices/, I could just buy a replacement engine for $8,220 (plus shipping). Or heck, I could go ahead and upgrade to a 250HP with fresh water cooling for ~$10,500.

The cost of buying a full replacement engine is about the cost of replacement parts? What am I missing? Presuming I stick with this engine, why shouldn't I just buy replacement engine instead and drop it in with the help of a shop instead of repairing the existing one?
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Is your current model only a 200hp motor?
 
Marcus Matos said:
Thank you for that. I have a few more days until the insurance company finishes doing their thing. In the meantime, I've started looking at engines and happened to come across a price list for 2021 4.5 engines. According to https://www.proboats.com/mercruiser-2020-engine-prices/, I could just buy a replacement engine for $8,220 (plus shipping). Or heck, I could go ahead and upgrade to a 250HP with fresh water cooling for ~$10,500.

The cost of buying a full replacement engine is about the cost of replacement parts? What am I missing? Presuming I stick with this engine, why shouldn't I just buy replacement engine instead and drop it in with the help of a shop instead of repairing the existing one?
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The full replacement engine is complete and drops right in. Much less labor cost.

If you just replace the long block, you’re paying the mechanic many hours labor to swap your used parts onto it.

For someone like yourself that doesn’t do your own repairs (this one at least) I would highly recommend the complete replacement engine. The overall cost will be much lower, everything will be new, and you’ll have your complete old engine that you could sell individual items off of to recoup some costs.
 
Espos4 said:
The full replacement engine is complete and drops right in. Much less labor cost.

If you just replace the long block, you’re paying the mechanic many hours labor to swap your used parts onto it.

For someone like yourself that doesn’t do your own repairs (this one at least) I would highly recommend the complete replacement engine. The overall cost will be much lower, everything will be new, and you’ll have your complete old engine that you could sell individual items off of to recoup some costs.
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I would agree with this but only if you're set on replacing the manifolds and risers. Otherwise it's wasted cost. If you're definitely going to replace the manifolds and risers, it's actually cheaper to get the full engine.... it will include the full exhaust, plus intake/injection, ECU, accessories, etc.
 
Well now I'm getting some conflicting information. A local place called me and said the full engine (by itself) would be closer to $18K (off the top of his head) - waiting to hear back from a couple more "authorized sellers" off the Mercury site...
 
douglee25 said:
I would agree with this but only if you're set on replacing the manifolds and risers.
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Thanks for that. I need to talk with the service manager again and figure out whether that was in the quote out of an abundance of caution or if there was confirmed damage.
 
Marcus Matos said:
Thanks for that. I need to talk with the service manager again and figure out whether that was in the quote out of an abundance of caution or if there was confirmed damage.
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It was listed as a part number in your quote. I assumed it was being done based on that info. The manifolds and risers add approx $1600 plus gaskets to your total at internet costs. +25% more based on your marina's estimate.
 
douglee25 said:
It was listed as a part number in your quote. I assumed it was being done based on that info. The manifolds and risers add approx $1600 plus gaskets to your total at internet costs. +25% more based on your marina's estimate.
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Talked with the manager and learned that's been their general tactic - to just replace everything in the cooling system to avoid any surprises. There may or may not actually be any damage to those parts but I'm not sure I want to pay any more labor costs for them to look at it.

Do you (or anyone) know if there's a reasonable way for me to check these parts out or does it require some special tooling to test them under pressure?
 
Marcus Matos said:
Talked with the manager and learned that's been their general tactic - to just replace everything in the cooling system to avoid any surprises. There may or may not actually be any damage to those parts but I'm not sure I want to pay any more labor costs for them to look at it.

Do you (or anyone) know if there's a reasonable way for me to check these parts out or does it require some special tooling to test them under pressure?
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I'd have to look at the parts and do a visual inspection to see how it's setup. Yes, you could do a pressure test.
 
Welp, just got the news from Progressive that they're denying the claim due to improper winterization.

I'm still trying to figure out how whether dropping in a complete 4.3L MPI will be a reasonable path forward. I saw one article calling the 4.5L a "direct replacement" for the 4.3L V6 (i.e. same bolt patterns and engine mounts) but haven't been able to find a similar claim elsewhere - anyone here done that repower and able to confirm?
 
Marcus, just a side note... a 220HP 4.3LMPI is actually less powerful than the 200HP 4.5L. This is because of the torque curve and the usable power comes on much quicker than the hybrid GM/Merc 4.3L.

In my opinion, I would first find out exactly what has been cracked - you may only need to replace the block (short block) - assuming you can find one, that is. But, as noted above, a lot of this depends on how much of this you are comfortable doing yourself.
 
Why did it go into limp home mode? Is there water in your oil? If so, it will look like tapioca and the bearings will soon be gone. You've fixed the blown frost plug and that has substantially limited the water flow. Your bilge pump may be able to handle it as your raw water cooling is not pressurized. You could install a 2nd pump to handle any excess and as a back-up. Not perfect, but you don't have to tell you guests that your boat leaks. This is not going to get any worse. One of the catalyzed liquid steel products could reduce or divert an external leak from the electricals. Meanwhile, you could list it in Craigslist and Boat Trader for $5,000 off, say $25,000; default on your loan and let the bank deal with it; park it in a bad neighborhood; or, donate it. Call the local marinas and offer it at your bargain price; they have parts at cost, surplus labor and could flip it. You could hire a mechanic by the hour on the condition that you would do the repairs together and you would be the helper. A friend without calluses built his own house with this arrangement and got a good result.
 
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