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470 head gasket kit

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Reddman

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Hi all, I am going to start working on my motor (470 Mercruiser) this weekend & was wondering if there is a complete set of gaskets for head R&R or do you have to buy them separate? Thanks for your help.
 
the head, intake,valve cover and exaust are all 460 Ford truck motor parts. A full kit Sierra 18-4381 s/n 6916779 & up
 
I have heard not to use automotive head gaskets for marine applications. Is this a fairy tale? Also I have heard the Sierra gaskets don't hold up & to use only Mercruiser. Is this BS also?
 
the Fel-Pro items work just fine. The biggest problem with these motors is "operater malfunction"
You cannot even think of overheating these motors .Normally there 160-165 temps, I prefer a bit cooler thermostat but thats my preference. Pushing it hard, maybe 170 ish any hotter and you lose the head gasket.
Trying to start it with a jump pack or battery if you have a dead battery. Will wipe out the stator coils and/or the regulator.
The 3rd item are the camshaft seals with the weep hole. Repairable with "Speede-Sleeves"
 
Thanks that helps, maybe I can have it back together & go for a boat ride Sunday.
Is it very expensive to convert to a normal alternator with built in regulator?
 
I haven't converted but I have been pricing out the cost. $400-500. for a special made bracket, plus the cost of the marine alternator. If it works, I'd leave it alone and go for your boat trip. :)
 
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Reddman said:
I have heard not to use automotive head gaskets for marine applications. Is this a fairy tale?
If the engine is Raw Water Cooled, that is correct information.
For a Marine Engine that is fitted with a Closed Cooling System, a high grade automotive head gasket will work.

Also I have heard the Sierra gaskets don't hold up & to use only Mercruiser. Is this BS also?
The Merc gasket might be specially designed for Cast Iron cylinder head against the Aluminum cylinder block.......... I am not sure.
Perhaps check out the link that Bt Doctur posted (post #9).

Click to expand...


Also note that the Merc designed 470 has had it's issues, and because of that it was discontinued relatively early.
I would not go over-board with expenses on it.


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Well the tear down didn't go all that well. The head gasket was leaking, but also the exhaust valve push rod on #4 cylinder was disconnected from the rocker arm, the top of the head & valve spring have surface rust like the oil pump quit working & #4 cylinder was badly rusted. Not sure I want to put any more money into this boat.
 
This is a common issue..............unless you can find where the water came from ( exhaust manifold and associated parts maybe have them all pressure checked) and then have the head repaired if no leaks are found, checked for flatness, valve seat repair, valves, springs if needed and replace any and all bad parts that are identified by a machine shop professional ( push rods, springs etc) then it is time to deep six it.

As long as the rods and pistons are good you could salvage it....The head stuff is plentiful.
Its the block stuff that is not.



Been there done that on these.........

There are still some for sale if you do some research........might find one running........
 
I am not sure as it is not that simple....

I have never went that far... Only upper rebuilds, heads, cam, etc.

If you know of a good trust worthy engine machine shop in your area and you can get a service manual for engine specifications then it would be best to ask them what they feel they can do.

There is someone who participates here who has done complete rebuilds....maybe search for other 470 related topics.
 
Thanks kghost, I am going to crunch some numbers tonight. You never know I may have a nice Caulkins trailer, a 21' hull & a brand new 1:84 out drive for sale (less than 30 hours) tomorrow.
 
Based on your boat configuration, if you have aft to forward stringers that motor mounts could be mounted you easily upgrade to a V6 or even a small V8.

Plenty of those COMPLETE drop ins for sale..............

May be a big project but no bigger than rebuilding that motor........
 
I have thought about that & I know I will never come out ahead on this project but I don't really want to get rid of it. This is a really good Columbia river boat when running & we're suppose to have 900,000 + Chinook salmon returning this summer.
 
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