i asked my mate to flow test my later model 4.3 vortec heads (2014/15 Mercruiser) to check if improvements could be made to get quicker RPMs off the line , he came back at me saying " leave them as they are " ,> for a 2 valve per cylinder head they are pretty darn good.
he basically skimmed them and gave them back.
the crank and rods i am using ( 2011 Mercruiser ) i had checked for balance , a new harmonic balancer was highly recommended and some lightening to the flywheel ,aside from these 2 things rods and pistons were good to go , i got told it was a good set once flywheel and new balancer was done .
a set of AM push rods and full roller rocker system helps to smooth things out .
camshaft is stock from a 2011 Mercruiser 4.3 ,checked against 2 others 1988 flat tappet and 2015roller and said to be a good grind for a boat motor.
the guys that work on my stuff know i am hard on motors so they try to do the best they can so i don't blow **** up.
my new built 4.3 revs very easy (too easy) to 5k and will ping 5500 rpm with little effort , guessing (have not been there yet ) 6k+ is not out of the question on this motor.
I'm not going to get into how durable this motor is , but so far it feels strong and has more power than i need in the Maxum .
i have not yet had a chance to get it run in yet , but i am sure its going to be a good motor.
