Mercruiser 140 head retorque proper technique

[Doug L.]

Hi,

I have a Mercruiser 140 3.0L that has just completed its first 20 hours of the break-in and is now time to retorque the head bolts per manual #10. I was wanting to know if anyone can shed light on the proper method for retorquing the head bolts? Should the engine be cold? Loosen one bolt at a time (following the proper torquing pattern), then torque to spec? Also, should the valve lash be readjusted after retorquing? Really appreciate any input on this! Just want to make sure I do it right.

Thanks,
Douglas

 

[Scott Danforth]

it really depends on the head gasket you used. was it a stock GM gasket? a Felpro metal gasket? a cometic? many gasket types do not require a re-torque.

 

[Doug L.]

Hi Scott,
Thank you for your reply. I did not consider that! The head gasket I am using is from Felpro part #17200. Are you familiar with this specific gasket?

Thank you, Douglas

 

[Scott Danforth]

per the felpro head gasket instructions https://drivcat.com/livedocs/CI1963.pdf

if you were going to re-torque (primarily for extreme use such as racing), you should have done it after the first time it ran and then cooled down

however I have only ever done an initial torque and run on felpro head gaskets.

after 20 hours, you can check the torque on them if you want, however depending on what sealant did you use for the head bolt threads, you may develop a leak? if you used permatex #3 you would be fine to re-torque

 

[Doug L.]

Appreciate the pdf! I'm def not racing. I used permatex #2 to seal my head bolt threads. Think I would be safe to retorque with that sealant if I choose? thanks