Motor Rebuild - The unplanned project

[Andy454]

It's in!!
After church my neighbor and I got the motor set into the boat, got the motor mounts bolted up, attached the V-drive and started to hook up the odds and ends. Didn't quite get to starting it up, but I took tomorrow off to get it buttoned up and lake tested.




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[Andy454]

Wow, the boat runs great!!
I didn't get any pics or vid yet, I was a little preoccupied with the QC details, but they will come. The only thing that needed additional attention is the propshaft packing seal, I would have loved to replace with a carbon ring set up, but budgeting need verse want plays in some times ($15 vs &300).
I'm just glad it's in and running!!!


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[Andy454]

Installed the new stuffing into the stuffing box over the last 2 days.
Today lake test!!
And all went swell!!
Motor ran great, no leaks or squeaks.
I will post up a video once I can track down my son and get it from him.

Over all it was a long project, but good to have this part done.



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[PaceWithGrace]

Congrats! Glad to hear it went well.

And thanks again for posting your experience.

[Andy454]

I thought I would provide a conclusion for this motor project.

Had some delays, to
-Insert the Lego Movie song (everything is awesome!!)-

We have logged about 10 hours and no surprises, in fact it runs beautifully. I had the prop sent out and reconditioned and changed the oil and filter after 5 hours. This weekend we were out Thursday and Friday for about an hour each, Saturday for 4 hours and today another 2 hours and to my kids delight finally did some tubing.

Real happy that it has all worked out and we can sit back and enjoy the lake!!


Here is the prop, and pictures don't do it justice, it looks great!!


And here are some fun lake pics!!


My next post has some vids - kind of dorky but whet ever..




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[Andy454]

......Here are my dorky videos.....

First, just after changing the oil.

https://vimeo.com/170399062

And easy crushing on Friday
https://vimeo.com/170399567

Thanks to everyone that has followed along, now I should have more time to participate in other postings!!


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[jslayde1]

Nice work man!

[surfidaho]

Awesome. Fun lake pics make it all worth while.

[chpthril]

whats up with the double nut on the shaft? That prop nut looks like it needed to be retired years ago and the nylon is not on the threads. Looks a little sketchy.

[Andy454]

Good eyes,
The other nut is acting as a washer until parts come in.
I agree it is a little sketchy.
[emoji57]


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[boatwakes]

Youre going to have some problems with that engine now if you haven't already and here's why: Mercruiser rates that engine at 375 HP and maps it's fuel and timing curve accordingly. The camshaft is ground retarded 4* in order to eliminate the detonation issues they had because of the fuel map running too lean in the midrange rpm. My advice would be one of two things: 1)change the cam back to the original grind before you blow the top of (usually number 5) one of your pistons off or 2) see if you can get your ecm remapped to match the camshaft profile.

[boatwakes]

Also, check your total timing at 3000rpm with a warm engine, it should be at or near (within 2*) of 32*, no timing computer activated. The ignition module in the distributor you buy at autozone only allows for 8* advance, the mercruiser marine module adds 24* and is the correct unit. If the engine runs with only 8* total advance in the computer plus the initial timing of 10*, your aggrevating the already lean mixture in the cylinder by running retarded and building excessive cylinder heat.

[Andy454]

Another 2 hours on Friday and 3 of active time on Saturday was great!!
One small detail, the battery felt a little weak when restarting after a rider change [emoji848] the starter is new, and the battery was new last year, so not sure. It didn't leave us stranded, but thinking I might get a second battery.

From Friday we had very active riding, almost non stop. So I was able to get a good idea of the fuel use. Running between 3200 and 3800 RPM on average we used 14 gallons of fuel. I feel that's not too bad for a big block!


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[Germaine Marine]

I hope Andy had all that done boat Wakes... Ill cry for him if he grenades it and has to start over so soon...

[Andy454]

Also, check your total timing at 3000rpm with a warm engine, it should be at or near (within 2*) of 32*, no timing computer activated. The ignition module in the distributor you buy at autozone only allows for 8* advance, the mercruiser marine module adds 24* and is the correct unit. If the engine runs with only 8* total advance in the computer plus the initial timing of 10*, your aggrevating the already lean mixture in the cylinder by running retarded and building excessive cylinder heat.

During the off season I did a little digging from your input. What I found is that the Ignition Module that is mounded to the distributer, Mercruiser part number 811637, is the same part on most all MEFI GM based V6 and V8 motors 1994 – 1998 with few exception, it is also on OMC and Volvo Penta GM based motors also and there is no change to the part as it crosses to the realm of the road going motors. For the ignition timing, that is housed in the SPARK CONTROL MODULE part number 805443T and that is obsolete at this time, so hopefully it doesn’t go bad.
I do appreciate your input, it was a good exercise to verify the parts.
In the process I also found a neat reference guide, it covers MerCruiser EFI Engine History and Major Changes from 1993 to 2005 and has tons of great information (over 200 pages of tech info). I would post it here but I don’t see a way to upload a PDF. In that I found the rated HP spec for the motor, according to MERC: 454 Magnum EFI/MP – Tournament Ski Inboard (395 psHP/4600-5000 rpm)
Any way,
Just a recap of the end of the year, the motor developed a fuel leak and I didn’t have time until the very end of the season to find it. What I found is an oring on an injector had been pinched in the reassembly and didn’t start leaking until almost 20 hours of operation. it got fixed in just enough time to winterize.
So now I anxiously wait for spring to fully arrive!!