It would be a lot cheaper to put twin turbos on it and he could leave the hatches alone.

Cool. I always just thought you were talking smack all these years. Lol. Just kidding I always respect your post and are a huge contributor to this forum.

Thanks, I was trying to find some hope that that maybe I wont end up screwed with my top end decision. I don't have the coin right now to fix a new motor that has yet to be run.

Eddie

Why not upgrade to a 55MM Cam and .903 Morel high rpm, especially in high HP applications? Mine have been flawless!

Any power adder will be under hatch no way she will let me change it, and honestly I don't either haha

My engine came already with a 55mm cam, but oddly enough, with an .842 lifer in a bushed bore.
We machined the bushings for a .903 lifter.
I was locked into using the 55 cam and decided the lofter upgrade was a good investment.

That said, I wonder if it would be worth it to make the mods in a fresh build. I know you have to start with an aftermarket block, but most probably already are anyhow.

I have and do use a 55mm/.904 combo on a regular basis. We are doing some 1075's with those mods right now. That is certainly the way to go if you are scratch building one. All of the ones that I mentioned above were already assembled, so it wasn't really an option to machine them for the larger cam and lifters. They would have to come all the way apart to do that.
Eddie

Hey Eddie.
So, the advantage of a 55mm is still worth it even in a relatively low RPM marine application?

Is the main advantage the better geometry with the larger base circle?

Also, what are you using for cam bearings on the 55mm stuff? Roller of Babbitt, is what I'm wondering, not so much manufacturer?

So I wonder what happens IF they regrind a cam?? Is it "re-heat treated"? Heres a story of a cam I had a fiasco with at one time, NOT MK'S FAULT, I built a 540, MK spec'd the cam, said I would make 950 hp on dyno, got to dyno at Crocketts, fired up motor, ZERO oil pressure at anything below 1000 rpms BUT would jump to 45-70 psi at 1100 rpms up, Crockett said lets pull er off, you screwed something up on this motor building it. I made the judgement call to go forward (cut filter open, clean as a whistle), set idle at 1100 for now, we are on dyno, dont want to do this twice, I will figure out my idle oilin problem at home when we are done. Tuned, made our number, everything was good except idle oil pressure,
Got motor back to my shop, pissed around testing all kinds of stuff, found with intake manifold off I had TONS of oil blowing around top of lifters when they were in right spot. Turns out this merlin 2 block I had had fairly short lifter bores and they had a massive radius at top that allowed lifter band to enter it allowing oil to blow out with no resistance (morels), this was back in like 2005 I think and they just wasn't alot of info on what worked and didn't work at time. Pulled cam out, sent it back to Cam motion and they reduced base circle either .050 or .100, re-installed cam in motor, had great oil pressure, ran that motor for a little over 100 hours before upgrading it another 170 hp or so, cam looked perfect when it came out, saving it to go back in that POS merlin block one day, so if cam was already cut from a core with a certain range THEN reduced even just .050 all the way around it either had to be cut thru the heat treat or re heat treated to last 100+ hours ran at 185/190 seat and 460 open with morels to still look like new??

At this point Tim you need to ask yourself will you really be happy with a low 70mph boat that cost 3 times what you planned to get it there???? At the time your build made sense and if everything worked out you could have enjoyed the reliability for years and saved your money. But things have changed.

I would take some time to carefully consider upgrading boats, or adding forced induction.

I honestly believe you will not be satisfied unless you hit 80mph next.

Seriously