Mercruiser 485 3.7 litre new head!

[billywhizz]

Hello Fellas, I have just this week fitted a new/remanufactured head along with new rockers, push rods,oil change etc, all good, went out to Sea yesterday but kept the revs down to below 2000rpm, can anybody suggest a running in time or sequence (assuming that it needs running in) in terms of hours? for your interest/information the boat is usually up on the plane at around 3000rpm and cruises at 18 knots at 3400 rpm, many thanks

 

[mkast]

Re: Mercruiser 485 3.7 litre new head!

No break-in on a cylinder head.

 

[stonyloam]

Re: Mercruiser 485 3.7 litre new head!

The only thing you have to do with the 3.7 is retorque the head after it is up to operating temp. If you did that you should be good to go.

 

[billywhizz]

Re: Mercruiser 485 3.7 litre new head!

yep, do you mean re torque whilst it is still hot, or run it up to temperature and re torque the next day after it had cooled down, ( which is how i did it) but only one bolt moved 1/2 inch? thanks for your time,