Im redoing the pair of ZUL motors in my 39' Dominator - one grenaded and one is just a refresh. They are 557" with Dart heads, JE pistons (custom with a slight dome..compression??), Merlin intakes, big holley dominators and big solid cams. Wont know the exact size until the tear down next week but they wouldn't even clean up/run smooth until 3000rpm. Even with good ignitions, tune, fuel, etc. Their big. Anyhoo, Im wondering what schools of thought people have as to whether I stay with the solids and go the same size or bigger, or run a big hydraulic set up. Their IV blocks, and made either 650 or 750hp from ZUL. I like the idea of NOT having to pull exhausts off to adjust valves, but also don't want to change a winning mix from a builder like that - like proofreading a Keats poem

Would be awesome to dyno the running engine first, then you know what you had and you know what you gained.

Ben at precision power offshore does this all the time and its always surprising what he finds. Some famous engine builders "said" power levels are less, some are more.

there is no doubt that a solid roller cam can make a lot of power but today,s hyd roller cams have come a long way.not knowing how old your current setup is or what the cam spec,s are it,s pretty hard to say what direction you should go.after you get the engine apart let us know what you have and we can go from there.

These motors are not roller, which would be nice. Im also not in the hunt for horsepower so much as what others have found reliable and still made good power. These motors will make well over 600hp without going crazy and that's good enough for me since I am still stuck with TRS drivelines. My trannies are built heavy but as we know, the drives are shakey when you start throwing big horsepower at them.. didn't know if there was a big preference towards or against solid cams that's all. And I absolutely agree about what it says on the "build sheet" is often times not what comes out the pipes! I will keep it posted when their torn down and get the specs for whats in them. and thanks for the replies

[ am guessing that it is a fairly old build.nobody uses flat tappet camshaft anymore.

Here's a good suggestion on cam choice.... Bob Madara of Marine Kinetics (585) 654-8583 is an excellent consultant on cam combinations for marine offshore hi-perf engines for any existing heads, cubic inches and application you have/want.

and just like flat tappet camshafts, no one is using Bob anymore either.

Impulse, if you decide to hydro roller, I have two sets of almost new Howards roller lifters

http://www.offshoreonly.com/forums/s...2-lifters.html

Snap that +1

just not true about bob.i don,t mean to start anything but i use him and am very happy with his design work and the prices on the parts.except for a few morell lifter problems everything has been perfect.he immediatly sent me replacement lifters at no cost.who else in the marine industry does that?i,m not going to get in a pizzing match with those who don,t like bob,i am simply stating my experiance with him.