3.7 (470) head RE-torque ?

[gettin'even]

The Merc service manual says to final torque the cylinder head to 130 lb/ft. The retorque after engine is brought to operating temperature (not exact words in the manual).
My question is.... Do I let the engine cool down before re-torquing, or is it done with engine at operating temperature?

Thanks in advance,
Mark

 

[TowRoper]

Re: 3.7 (470) head RE-torque ?

hiya, you do it at room temp and don't forget to do it by sequence

 

[Don S]

Re: 3.7 (470) head RE-torque ?

My question is.... Do I let the engine cool down before re-torquing, or is it done with engine at operating temperature?

Yes, let it cool down to room temp. What they were trying to indicate, was to retorque the head after first heat cycle.

 

[Don S]

Re: 3.7 (470) head RE-torque ?

hiya, you do it at op temp and don't forget to do it by sequence

Think about it, the temp would vary from the time you started to the time you finished. Then you would have different torques on each bolt.
After an engine has cooled and all at room tempeture, everything is equal.

 

[TowRoper]

Re: 3.7 (470) head RE-torque ?

oh i agree don s 100% i had my head up my bilge and fixed my wording

 

[natemoore]

Re: 3.7 (470) head RE-torque ?

The Merc service manual says to final torque the cylinder head to 130 lb/ft. The retorque after engine is brought to operating temperature (not exact words in the manual).
My question is.... Do I let the engine cool down before re-torquing, or is it done with engine at operating temperature?

Thanks in advance,
Mark

That's a good question. I was thinking just the same thing. Are you that far along in your rebuild, or are you researching?

Could you find my "crankcase installation questions" thread and see if you have anything to add? I will also be posting some piston ring questions here in a sec.

 

[gettin'even]

Re: 3.7 (470) head RE-torque ?

Thanks for the replies. I kinda figured re-torque after cool-down, as that's the way it's done with performance auto engines, just wanted confirmation. I figured you can't assume the normal way of doing things applies to a 3.7..lol.

 

[gettin'even]

Re: 3.7 (470) head RE-torque ?

That's a good question. I was thinking just the same thing. Are you that far along in your rebuild, or are you researching?

Could you find my "crankcase installation questions" thread and see if you have anything to add? I will also be posting some piston ring questions here in a sec.

After a re-torque, I'm ready for a shake-down run on the river. After some coaxing, got her fired up this A.M. Runs alot better without the broken pistons and scored cylinder walls.....go figure.

I'll find your thread, and check it out.

 

[natemoore]

Re: 3.7 (470) head RE-torque ?

After a re-torque, I'm ready for a shake-down run on the river. After some coaxing, got her fired up this A.M. Runs alot better without the broken pistons and scored cylinder walls.....go figure.

I'll find your thread, and check it out.

Here's the thread: http://forums.iboats.com/showthread.php?t=348898