1999 454 Mag MPI just quits - videos

scoflaw said:
Yah, post up a pic of this relic.
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Which one?
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Back on it next week. What's your choice for plug and play heads? Like anchors, shipping will matter.
 
Been here since 12/13. Just finished a month long center console project. Broke a stringer that cracked the hull on my old CC, transferred all the good parts to another boat trying to save a buck and keep busy
 
scoflaw said:
Been here since 12/13. Just finished a month long center console project. Broke a stringer that cracked the hull on my old CC, transferred all the good parts to another boat trying to save a buck and keep busy
Click to expand...
OK, it will be a few weeks until I start yanking heads on Beach House. Finishing my Cat repower. Finally found a Yammie to put on it. Of course that required a complete redo of the dash, harnesses, binnacle, and oil feed tank, etc etc. Getting closer.
 
douglee25 said:
So you're putting brand new heads on it??

Did you do a leak down?
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about 6 pages ago. Consensus is the valves are floating at 3000+ rpm. (post 61, page 4) I need to look at a hydraulic lifter that was on #8 where a push rod got pushed through the rocker. If I'm going that deep, and for this cheap, I'll replace rather than rebuild. Hopefully the cam is ok, but if not, while I'm there......
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370Dancer said:
about 6 pages ago. Consensus is the valves are floating at 3000+ rpm. (post 61, page 4) I need to look at a hydraulic lifter that was on #8 where a push rod got pushed through the rocker. If I'm going that deep, and for this cheap, I'll replace rather than rebuild. Hopefully the cam is ok, but if not, while I'm there......
View attachment 100595 View attachment 100596 View attachment 100597
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Dang. Reminds me of a 454 I rebuilt for my 69 Camaro. I bought it from a guy who had it "rebuilt." It had a pretty good "tick", but ran. Turns out the idiot that did the rebuild installed the spider (holds the roller lifter holders in place), but not the hold downs which stop the lifters from spinning. A few of the lifters turned in their bore so they were riding 90 degrees out on the cam... Ugly to say the least.
As ugly as it was the block was fine and the heads were easily rebuilt.

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And, I’m almost ready to start. Been restoring/repowering the Cat so we have something to hit the beaches and coves while Beach House is down. Also getting a full aft Bimini, so I will wait for that cover before starting. Rain and sun plentiful this time of year
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And, we're off!
Weather finally cooled down enough that I can stand to be in the engine room with a full bimini cover, and a box fan blowing the salon air conditioning into the cockpit.
Today, I decided to do the complicated one first. Port engine gets torn down to the block for new heads.
I've taken some pics that I will post along the way, but am not trying to YouTube document it.
The biggest surprise so far, is the 6 item bullet list that Service Manual 23 has for replacing the heads. One line in particular:
"And remove anything on the front or rear of the motor attached to the heads"
What a friggin' "move the piano" statement. Especially for a MAG MPI Horizon closed cooled engine. I had both sides of manifolds, extensions, and elbows off in 2 hours, including gathering up all the tools I knew I would need and getting them onboard, and pulling the cushions, seating, and floor hatches. 6 hours later, I'm still pulling just about everything except the crank pully and the raw water pump off the front and sides of the engine. Then, I get to mess with the back end, but that's not nearly as complex.
Scof, come on over, and bark at me while handing me wrenches..........
I did find the beginnings of reversion in #4, as it has always been on these motors in this boat. Anyone have an opinion on hammering in a 2 foot section of SS pipe to the elbow to make reversion basically impossible? I may do that on re-assembly.
 
370Dancer said:
And, we're off!
Weather finally cooled down enough that I can stand to be in the engine room with a full bimini cover, and a box fan blowing the salon air conditioning into the cockpit.
Today, I decided to do the complicated one first. Port engine gets torn down to the block for new heads.
I've taken some pics that I will post along the way, but am not trying to YouTube document it.
The biggest surprise so far, is the 6 item bullet list that Service Manual 23 has for replacing the heads. One line in particular:
"And remove anything on the front or rear of the motor attached to the heads"
What a friggin' "move the piano" statement. Especially for a MAG MPI Horizon closed cooled engine. I had both sides of manifolds, extensions, and elbows off in 2 hours, including gathering up all the tools I knew I would need and getting them onboard, and pulling the cushions, seating, and floor hatches. 6 hours later, I'm still pulling just about everything except the crank pully and the raw water pump off the front and sides of the engine. Then, I get to mess with the back end, but that's not nearly as complex.
Scof, come on over, and bark at me while handing me wrenches..........
I did find the beginnings of reversion in #4, as it has always been on these motors in this boat. Anyone have an opinion on hammering in a 2 foot section of SS pipe to the elbow to make reversion basically impossible? I may do that on re-assembly.
Click to expand...
It's a bitch for sure. Easier to pull the motor and disassemble on the ground imo. Not sure I follow the hammering of the SS pipe in the manifolds.
 
HawkX66 said:
It's a bitch for sure. Easier to pull the motor and disassemble on the ground imo. Not sure I follow the hammering of the SS pipe in the manifolds.
Click to expand...
Not the manifolds. The elbow outlets. The idea is to introduce water to the exhaust further downline than the meager 4-6" of the elbow. It's partially folklore, except on Offshore Only. But, they are all dumping at the transom, or the sides. Probably no water lift mufflers or underwater exhaust like we have, so I remain skeptical.
I'm committed to stripping the front and the rear to get these heads off, and new ones on. I just wish Brunswick was a little more forthcoming with sequence. Oh, wait, they make bowling balls. This is still virgin territory for them.
 
370Dancer said:
Not the manifolds. The elbow outlets. The idea is to introduce water to the exhaust further downline than the meager 4-6" of the elbow. It's partially folklore, except on Offshore Only. But, they are all dumping at the transom, or the sides. Probably no water lift mufflers or underwater exhaust like we have, so I remain skeptical.
I'm committed to stripping the front and the rear to get these heads off, and new ones on. I just wish Brunswick was a little more forthcoming with sequence. Oh, wait, they make bowling balls. This is still virgin territory for them.
Click to expand...
From the little I know about reversion, I think I'd go with taller risers over the longer elbow. Only sure thing is that it's not my expertise by a long shot.
 
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