mptrimshop

I'm running a pair of 2000 mercury racing 377 scorpions with almost 300 hours on them. I have not done a leak down yet, but with the age of the motors and knowing they sat for a few years unused, I'm thinking of taking the job on. My question is do I search for a good set of aftermarket heads or just take off my stockers and have them gone threw. I was told by a very reputable engine builder that my vortec heads are not worth doing anything along the lines of porting because by the time you fdo what needs to be done the cost will be over nice aftermarkets. What heads do any of you guys have experience with?



Thank you for your time
Mike

mptrimshop

Not a lot of small bock guys on here....

proboat-wes

order yourself a good set of aluminum heads,vortec heads do nothing but crack,valves are crappy quality(tulips the exhaust valve)good valves in good aluminum heads equal dependability,and hp..

bobl

I've built quite a few marine small blocks. The question is, what are you trying to accomplish? Vortec heads are fine and will support well over 400 hp. If you're looking for more, then some nice aftermarket heads would be the ticket. Your heads should be fine with just a refresh if you're not chasing more power. A good set of headers and better cam would be a good choice. Most instances of Vortec head failures that I've heard of are from overheating and detonation. Being a fast burn head, they don't require a lot of total timing.

Bob Lloyd
Full Throttle Marine

mptrimshop

Well I'm always on the quest for a little more power. If I were to switch to aluminum heads what ones would you recommend? I always like to know my options if for just se weight savings...not sure what I can expect to pay to have the heads gone threw, but I would like to know the cost of a set so when I do get the $$ I can compare. I don't really know to much about the motors to be honest. Every time it ask anyone that would know I just get told that they are a great set up that was exspensive.

mptrimshop

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Most info I have found on them

bobl

You also need to realize if you start making changes you'll need to reprogram the ecm. There is not really a canned program out there. To get it right you would need to install an 02 sensor and dyno the engines. Then send the ecm's and data to someone that can program them. The only 2 that I'm aware of are Mark Boose and Dustin Whipple. So, you need to be prepared to go all the way, or leave them stock. The 377 Scorpion is a nice package. They just made some compromises on the cam design to compensate for the stock exhaust. Good headers and different cam will put it well over 400 HP, but you'd still have to reprogram the ECM. You might be able to just add headers and get away without reprogramming. You would need to add an 02 sensor and see where it comes out.

Bob Lloyd
Full Throttle Marine

mptrimshop

Thank you Bob you have been very help full. I have contemplated sending the MEFI3 to Dustin for a tune. He offers a package for the 377. They are currently updating the website so it does not have the full detailed on there. I have talked to a few guys who have tossed headers and manifolds on this set up and have not seen a lot of HP gain. As for the the I was under the assumption I could find a few guys that have MEFI3 experience. I could be wrong.


Thank you again

bobl

I was assuming you have the ECM 555 computers. A lot of people can tune the Mefi 3, including me. However if they haven't done the exact configuration you are going to use, then it's not accurate. Headers alone aren't worth much. However they will allow a much better cam choice which will add more power. Same with just programming the ecm. It's pretty much tuned as good as possible stock. So unless you make changes reprogramming won't buy much, if anything.

Bob

mptrimshop

If I were to do heads,cam,headers what heads do you recommend ?