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1990 merc 7.4 head bolt torque???

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Old 05-13-2011, 07:16 PM
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Default 1990 merc 7.4 head bolt torque???

I have a pre mark v 7.4l that im putting heads back on. The clymer manual says 85lbs in 3 step for both long and short bolts....this seems like its not enough??? Does anyone have these specs? Thanks for the info!!
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Old 05-13-2011, 09:14 PM
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come on guys..I know someone has been into these engines and knows the cylinder head torque spec......!!
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Old 05-14-2011, 07:01 AM
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do what the book says. I've broken head bolts off with less than 85 lbs. It's not just the lbs its the streach of the bolt as well.
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Old 05-14-2011, 07:12 AM
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85 ft/lbs looks about right (that's what I torqued mine to).
Try this link: http://www.perfprotech.com/store/art...r-torques.aspx
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Old 05-14-2011, 08:50 PM
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i got the heads back on today and boy they are heavy when your standing on your head...I can't believe that every head bolt goes into a water jacket...I figured it would be more solid that that. I sealed them all up good so hopefully i'll finish it tomorrow and get it running. Hope all is well!!
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Old 05-14-2011, 10:47 PM
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I'm pretty sure the gm spec w factory bolts is 65 short and 75 long
arp bolts differ as well as studs, I have gone as high as 85 myself
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Old 05-15-2011, 04:32 PM
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I just did my 4.3 and they where 20-40-65.
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Old 05-15-2011, 07:06 PM
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wanted to have it back running this weekend, but the weather has other plans. did get alot done though..still have to put distributor in as well as shift bracket and carb. then hit the key! Maybe i can wrap it up after work this week. Want to hear the engine run again!!
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