Motor Rebuild - The unplanned project

[Andy454]

So last end of Augest I got my first real boat (I have had jet-skis and sea-dos).
I got an older Tige - 1996 PRE 2200, it was in mostly good shape but had sat for 3 years.

The items that needed attention was the fuel system needed a go through, gauges needed help, prop and a Full service.

Not a problem, I got a GREAT DEAL on it and in a past career I was a marine mechanic.

I ordered a new fuel pump, fuel lines and fuel regulater, had the fuel injectors rebuilt and then installed. Flushed old fuel, and replaced the filter and now time to test run!!

The boat did run when I perchesed it, just not well, now it sounded great running it on a flush in the drive way so the next step was to take it to the lake. At the lake things went well and we (me and the kids) ran around for about an hour.

While coming back to the launch bad things happened
The motor started making crunching noises and quit I had checked the oil, was full, oil pressure through the ride was fine so what gives???

I completed a compression test after coming back home and had no compression on cylinder 5

My hopes for a great end to the summer.... dashed!!!

I pulled the motor before freezing temps set in but didn't open it up until a few house projects were completed. Once I did, I was so mad at my self - a bolt had fallen down the intake that I didn't notice when I was replacing fuel parts.

[Andy454]

Pictures are worth a thousand words




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[Andy454]

Any way, things are turning around!
New/used block, new bearings, pistons, valves, cam and oil pump, some machine work and assembly has started!!




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[PaceWithGrace]

Thanks for the story and photos!

[ChrisSnow]

That's a lot work for a misplaced Bolt!

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[WYTige?]

I would have cried! I don't have the skill set and misplacing the bolt would be something I'd do! Well done on the rebuild. Can't wait to see more progress.

[Andy454]

Well, today has been productive!!!
Installed the crank, pistons, oil pump, and cam.

Everything turns nice!!

While I was at it, I figured may as well put a hot cam in it too!! So below is the stock cam spec, and the new.




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[Andy454]

I would have cried! I don't have the skill set and misplacing the bolt would be something I'd do! Well done on the rebuild. Can't wait to see more progress.

Yes, I did cry.
I was so upset, the motor only had 400 hours

[Andy454]

The motor is continuing to come along.

Oil pan, timing cover, finished the heads and mounted onto the block.
Hoping to get the rest of the odds and ends mounted to the block through the week and next week get it back into the boat!!



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[PaceWithGrace]

Looking good

[Captainkurk72]

Post a vid on startup. Would like to hear what the new cam sounds like.


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[Andy454]

I will, I'm geeked about it.


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[Andy454]

Today we had some more progress.
I installed the pushrods and rockers, primed the oil system, and installed the rocker covers and intake.


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[Bryan]

So I've torn into a couple engines, but one thing I've never really grasped are cam specs.. How exactly will your hot cam excel over stock? I'm assuming low end since this is a tow boat? I know they make 4x4 specific cams that have more power at lower RPM.. Is this kind of what your going for? Excuse my ignorance if it's a dumb question..

[Andy454]

The cam it self has .022 inch higher lift and it is a little fatter lobe holding the valve open a little longer.
With that the motor can suck in some extra air and fuel, so that is the idea.
How you choose a cam depends on the torque and horsepower figures play out, if you make the lift too big, you may end up with a lots of horse power high in the rpm range, but nothing down low. So when looking at different dyno run sheets, I wanted to find a solid torque curve that started low and held through out the usable rpm range of the motor.
A bunch of factors come into play as well, how much air can the head and manifold flow, can the fuel system keep up, can the exhaust let it all out.
Now most of this is measured at wide open throttle and most of us are running a constant range with someone on a board out back, so how usable the motor is while cruising is a big factor also, but dyno runs won't give that info well so you have to do some asking of people who have run it or something almost the same.

So a portion is unknown at this point, or until it goes in the water, but that is why I only went up, in essence 2 sizes.

Hope that helps,

Most people are afraid to do any mods to their motors because they are "marine motors" but that idea is a farce, the details are in how the motor was specked for the application, like for example the standard 7.4 mercruser is a truck motor with out the truck emissions and a different cam. The 454 magnum adds forged Pistons, large port heads and a different cam. All the newer blocks, for cars trucks or boats all have brass freeze plugs.



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