Mercruiser 3.7 (470) Head bolt torque?

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wbk017

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Does anybody know the head bolt torque for a 3.7
I just redid the head. Also manifold torque please.
also I was reading about alternator conversions. I have power steering
can I hang an alternator and get a longer belt and run both off the crank pully?
Thanks, Bill , NJ
 

Don S

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Re: Mercruiser 3.7 (470) Head bolt torque?

Yea, I know the torque, but that won't help you get the head on right with that open deck design.
What year or SN is this 3.7(470), I can post you a link to the proper OEM service manual
 

wbk017

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Re: Mercruiser 3.7 (470) Head bolt torque?

Please explain your statement about open deck design
Serial number is B517271 MCM 165
Thanks, Bill
 

Don S

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Re: Mercruiser 3.7 (470) Head bolt torque?

The open deck indicates the cylinder walls are not connected to the block at the top (Deck) like most engines are. Gives the cylinders a lot of extra movement when overheated. Which is why head gaskets usually fail when a 3.7 has any kind of an overheat.
In the picture below, the red lines show the open areas.

attachment.php


Here's a picture of a 3.0L engine that doesn't have the open deck. Notice how the cylinders have metal between them and the outer walls.
Never tried to explain that before, sure hope it makes sense.

attachment.php


Also, here is a link to the OEM service manual you can download for your engine. You REALLY need it.

http://www-alt.mercurymarine.com/mnetdata/SERVICE/CRUISER/Servmanl/08/cover.pdf
 

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wbk017

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Re: Mercruiser 3.7 (470) Head bolt torque?

Thanks for the info and service manual.
 

usfwalden

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Re: Mercruiser 3.7 (470) Head bolt torque?

I just purchased a 3.7 myself and could really use the service manual. It's a 190 serial number: A570030
 
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Re: Mercruiser 3.7 (470) Head bolt torque?

You should start a new thread of your own for your question instead of on this 2-year old archive.

They have been removed by Mercruiser, but there are a lot of Mercruiser Mechanics and 470 owners on here who have many hours on these set ups, so might be able to help if you have an issue.
Sorry,
 
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