Head bolt torque sequence

**"Aquahaulinass"** · 04-29-2021, 05:11 AM

I finally got my gaskets was wondering if someone could post the torque sequence and ft lbs? 1987 175 blackmax
Tx mike

**rock** · 04-29-2021, 06:47 AM

Start in the middle and work your way around. I torque to 35 lbs. On used bolts do NOT +90*.

Rock

**rgsauger** · 04-29-2021, 11:15 PM

And do them to 15, then 25, then 35 lbs. Three torquings. And oil your bolt threads with two stroke oil.

**25two.stroke** · 04-30-2021, 02:46 PM

This what what the book says, take it or leave it I agree 35 ft-lbs is good...I've gone more depending on how strong your bolts/studs are

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**Chaz** · 04-30-2021, 04:02 PM

Thats how I learned , in to out.

Then I started hangin out in the Top/Fuel pits and saw all of them torqueing out to in. Finally axed a crew guy , he said : The gasket is already tryin to get out .. grab it , best ya can ta make it stay .. Ahh OK ..

**25two.stroke** · 04-30-2021, 05:28 PM

Originally Posted by Chaz

Thats how I learned , in to out.

Then I started hangin out in the Top/Fuel pits and saw all of them torqueing out to in. Finally axed a crew guy , he said : The gasket is already tryin to get out .. grab it , best ya can ta make it stay .. Ahh OK ..

Have you found that works? In to out is a standard for damn near everything by all mfrs. Block halves, exhaust coers, intake manifolds, cars planes, wood siding... everything in to out.
But it don't really matter how anyone else does it or how the industry does it if a different way works ....

**Aaronhl** · 05-03-2021, 04:04 PM

Originally Posted by rock

Start in the middle and work your way around. I torque to 35 lbs. On used bolts do NOT +90*.

Rock

Do the used bolts snap with the plus 90 I did that on a recent engine

**25two.stroke** · 05-03-2021, 05:23 PM

Originally Posted by Aaronhl

Do the used bolts snap with the plus 90 I did that on a recent engine

The reason for not doing the +90 is for accuracy, not because the bolts snap. 30 ft-lbs, 40 ft-lbs...whatever you tighten it is FAR LESS than the tensile strength of those bolts. They can hold up to way more than that. The threads in the block strip before the bolts.
If you sheared a head bolt torquing it down to 30 or 35 then I would replace ALL the head bolts because they are compromised (either corroded, were over torqued in the past, or were some poor quality Chinese steel like they use to build our presently failing bridges and skyscrapers).

The 35 ft-lbs comes from an approximation of the 30ft-lbs + 90. Thats what the magic motor builders on here have figured out.

**rock** · 05-03-2021, 06:18 PM

New bolts are TTY hence the +90. Once the bolt has stretched the plus 90 will only strip threads in the block.

Rock

**Aaronhl** · 05-03-2021, 07:41 PM

Manual says +90 for the connection rod screws too, what damage could be done if using used bolts and turning it +90?

I actually couldn't turn my head bolts the full 90, I felt something was gonna strip, maybe I got another 45

**25two.stroke** · 05-03-2021, 07:55 PM

Not seeing that on the connection rod bolts in my 2.4 book. Maybe they said that in later books. Theres two things that will fail: the threads or the bolt. Connecting rod bolt failure can be catastrophic...bolt overtorqued, stretched, compromised...holds on at idle and revs freely...spin it up to WOT or jump a wake and when you come back down the extra stress pops the heads off the bolts...no fun.

**Aaronhl** · 05-03-2021, 08:09 PM

Hmmm yea well see what happens, thought I followed the manual, and who knows my torque wrench could be off, thought I tightened the bolts tight with some consciousness around stripping