Mercruiser 454 HP425 engine siezed - help!
#12
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Joined: Sep 2006
Posts: 1,391
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From: CapeComa,FL
Agreed.....
Anything north of 140ftlbs is gonna break a hung ring and wedge between piston and wall......meaning a simple hone and re-ring just turned into a month long vacation at hotel pay for everything new.....
Anything north of 140ftlbs is gonna break a hung ring and wedge between piston and wall......meaning a simple hone and re-ring just turned into a month long vacation at hotel pay for everything new.....
#14
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Joined: Jul 2007
Posts: 3,648
Likes: 32
From: Oneida Lake NY
#15
Last chance yesterday - got nice and warm but nothing at 140ft/lbs so manifolds off. Cranes look great and a little bit of emulsified oil - oil in sump good and not at all milky.
Exhausts show where the wet came up though so next weekend down to the bores and see whether a hone or a full teardown is in order.
Engine definitely a Gen V serial is OD725501, stamped UA on left hand bank - heads 14097088
Exhausts show where the wet came up though so next weekend down to the bores and see whether a hone or a full teardown is in order.
Engine definitely a Gen V serial is OD725501, stamped UA on left hand bank - heads 14097088
#16
After seeing your pictures, I wouldn't hesitate to just take it all the way down and clean up all the rust and install new bearings and rings. If it won't break lose there is a lot of rust on a couple of cylinders and I would be worried about the rings sealing. This way you are starting with a new motor and no questions in your mind. You are only talking about a couple hundred more dollars to do it right, and it's already going to be mostly apart. Sorry for your luck, but you know as a mechanic, that shortcuts usually don't turn out good. It's just another motor with a little different specs, and all you need to do is take it apart, clean it up and put it back together. Keep us posted and we can help out on the BBC.
#17
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Joined: Feb 2011
Posts: 2,640
Likes: 4
Umm, you are going to replace those manifolds, right? And if this engine was run in saltwater, I would get the block sonic checked and consider another set of heads that have not been run in saltwater. It eats them up inside the water jackets, and all it takes is one porous spot to break through and all the thousands you spend on the rebuild is down the drain. Also, if you are planning to continue running it in saltwater, invest in a closed cooling system. Good luck!





