Rebuilding top-end...while I'm at it?

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Danny_Ocean

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I'm about to replace my manifolds & risers. Then, I figured I should replace the head gaskets. Oops, gotta take off the intake manifold. Change those gaskets too.<br /><br />My question is, while I have the top-end apart, what else should I check, look for and/or replace?<br /><br />Thanks in advance,<br /><br />D. Ocean<br />Pompano Beach, FLA
 
Walt T

Walt T

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Re: Rebuilding top-end...while I'm at it?

What engine?
 
Bondo

Bondo

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Re: Rebuilding top-end...while I'm at it?

I wouldn't do Any of it,<br />Unless I found a Problem.........<br /> IF there's a Problem,<br />The Head Should go to a Machineshop for a Rebuild, <br />Before Reinstallation........
 
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wheels4

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Re: Rebuilding top-end...while I'm at it?

If it runs good just do the manifolds and risers.I wouldnt touch anything else unless there is a problem.
 
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Danny_Ocean

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Re: Rebuilding top-end...while I'm at it?

>What engine? <br /><br />454/330 Mercruiser<br /> <br />>Unless I found a Problem.........<br />>IF there's a Problem,<br />>The Head Should go to a Machineshop for a >Rebuild, <br /><br />I like the idea of "if it ain't broke, don't fix it", but at $500 per haul, I'd like to do as much preventative maintenance as possible while the boat is out of the water.<br /><br />D. Ocean<br />Pompano Beach, FLA
 
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imported_Mike_M2

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Re: Rebuilding top-end...while I'm at it?

The boat doesn't have to come out of the water for any of it!<br />Change the risers/manifolds, leave the rest alone. How many hours on it all?
 
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cjflanagan

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Re: Rebuilding top-end...while I'm at it?

If you are taking the exhaust manifolds and risers off, this is an excellent time to go ahead and do a compression test on each cylinder. If you find a bad one, or more, (greater than 30% off average of the rest). Go ahead and do a leak-down test on the poor performing cylinder(s). The point of the leak-down is to eliminate rings as a possible cause. If during the leak-down you hear hissing through the carb or out an exhaust port, then head work can help remedy the problem as it is the result of a valve train anomaly. If you hear hissing through the oil cap, then the compression problem is probably related to rings in which case head-work will be fruitless. <br /><br />If you do find a problem, and you do find that getting into the heads will make sense, this is an opportunity for you to go wild on:<br />* Checking each valve for deformations<br />* Checking each spring for proper strength<br />* Checking heads for hidden cracks (Magnaflux)<br />* Having the heads milled & planed<br />* Having each valve Pocket-Ported <br />* Replacement of all the gaskets with quality replacements<br />* Checking of all the lifters<br />* Checking of the rockers<br />* Checking of all the push-rods<br /><br />Find a good machine shop, and be prepared to spend about $400 bucks on a quality job, and another $125 or so on gaskets. Here's a great machine shop in my town. Mike has a lot of information about machine work on his website: Mikes Speed Shop He did a wonderful job for me over the winter.<br /><br />If you don't have a problem, save the money :D
 
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Danny_Ocean

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Re: Rebuilding top-end...while I'm at it?

>The boat doesn't have to come out of the water >for any of it!<br />>Change the risers/manifolds, leave the rest >alone. How many hours on it all? <br /><br />I can't play "boat mechanic" at the dock where I live. Many people would be upset seeing me come crawling out of the bilge covered in oil. I'd be voted off the island for sure!<br /><br />Hours are appx. 260.<br /><br />D. Ocean<br />Pompano Beach, FLA
 
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imported_Mike_M2

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Re: Rebuilding top-end...while I'm at it?

Danny, at 260 your engine is just a baby if well cared for! BP has a good idea, do a simple compression check, if all reads well leave it alone. If the test has a failure, then decide whether to dig deeper.
 
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Danny_Ocean

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Re: Rebuilding top-end...while I'm at it?

Great! Thanks for the pointers. Great forum y'all got here.<br /><br />D. Ocean<br />Pompano Beach, FLA
 
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Danny_Ocean

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Re: Rebuilding top-end...while I'm at it?

Completed compression check today. All eight cylinders read 160 (give or take one lb.).<br /><br />Water in oil has me concerned. If the problem is from the risers/manifolds, then so be it. A new set is on order.<br /><br />How will I know, before doing all this work, that the water isn't coming from a cracked block?<br /><br />D. Ocean<br />Pompano Beach, FLA
 
Bondo

Bondo

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Re: Rebuilding top-end...while I'm at it?

Pressure Test It......
 
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Danny_Ocean

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Re: Rebuilding top-end...while I'm at it?

I did a search on this forum and could not find the procedure for pressure-testing a block. Can anyone elaborate?<br /><br />Thanks again,<br /><br />D. Ocean<br />Pompano Beach, FLA
 
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Seaboo2

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Re: Rebuilding top-end...while I'm at it?

did a search on this forum and could not find the procedure for pressure-testing a block. Not sure on presure testing a block but what causes you to think it might be cracked? If it was winterized right (if even nessary where you are at) and it wasn't run hot I really wouldn't be concerned about it.
 
Bondo

Bondo

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Re: Rebuilding top-end...while I'm at it?

Danny,<br />Study the Water-Flow Charts in your shop manual.....<br />The Water System has an "In",+ an "Out".........<br />Plug one of them,+ Pressurize the other.....<br />It Should Hold 12/15lbs. just about Forever........<br />If It Doesn't.....<br />You've got to Find where it's Going.......
 
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Danny_Ocean

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Re: Rebuilding top-end...while I'm at it?

Not sure on presure testing a block but what causes you to think it might be cracked? If it was winterized right (if even nessary where you are at) and it wasn't run hot I really wouldn't be concerned about it. <br />
Click to expand...
Before I spend $$$ on manifolds/risers to cure the problem, I'd like to know if the problem actually lays elsewhere. If the block is cracked, I'll cancel my order for the manifolds and purchase a complete engine.<br /><br />Boat was winterized in VA, where I purchased it from.<br /><br />Thanks again,<br /><br />D. Ocean<br />Pompano Beach, FLA
 
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