I know they are going to be close since it is a side by side , and i don't know what it had prior to me getting it. All i know is that it had Blowers, I bought it as a repo from a bank. I just want to take some time and build killer naturals

Probably should pose your question in its own thread as I'm sure more than one of the OSO members have crossed this path before, and I'd be interested to know myself. I know my engine builder kept steering me toward staying with the tall decks in my boat over concerns for exhaust/transom location, when it was obvious I was going to be doing major engine work. I suspicion that all the engines are located on the same centers, and the transoms are bored for the exhaust based on the engine height and width at time of manufacture. I know they got performance gains with the staggered engines, but they had to be thinking about making them easier to work on when they decided to stagger them. What a nightmare to do anything to the side by sides while in the boat.

Mine has 34" centers and 16" x dimension according to the original build sheet. You can call Fountain and give them your serial number and they can provide you this information.

Heavy, ask your engine builder why he's using such a mild camshaft. 230 duration @ 50 is very, very conservative. Ask him if you could put a little more duration into the stick, like about 250-260, and look for around 640-660 lift.

I've used those Crane cams that have 632 lift, and 254-260 duration, and have very good success with them. They were actually alot milder than I thought they would be, and idled perfect @ 900-1000. Just a thought before you get too far into them to make a change.

Frank

It's really by my choice, with a little input from the builder, concerning agressive cam and valve timing versus water injestion, which is why the motors are apart. I wanted a nice boat that would run decent without having to work on it constantly, but even more than that would be mannerly around the docks or when maneuvering around other closeby boats. I probably will use it predominantly in fresh water (smaller lakes with a lot of traffic) and I didn't want the worry of fighting it to get it in and out of the water or take a chance on skinning up someone else's boat in tight quarters. I feel like the 565 cubic inches will give me all the power I want in open water and the milder cams will keep me out of trouble at idle, and will alleviate the possibility of water injestion. (My racing days are over but I still love a rush.) Getting ready to go to the dyno with the engines hopefully by the end of this week, so cams are already in. If I see numbers there that I don't like I might rethink the cam issue. Thanks for your advice.

Sucks to hear about that boat. I just cam across this thread. I had seen that boat run once recently also and thought it ran great, but it was only on the top.

Good luck with it.

Bring it back down when you gat it finished. I am shure Tbone would like a rematch. :evilb::eek::angry-smiley-038:

Heavy, I hope after all the work you're putting into the boat, you see the results that you're looking for. Good luck with it, and keep us posted.

little more duration?????
 

Yes, the cams are fairly mild, but coupled with a high flowing head, such as a 345 runner dart, I have had good results with this particular grind. But the MAIN REASON, is water reversion, I don't care who's exhaust you have on the boat, if its a std. wet system, and you got over 230 degs. at .050 your looking for problems. Believe me, I'm the first one to use a big stick, thats how you make big power, but from exp., my non-racing performance customers want reliabilty fore front, along with a broad power range. (not no mention if it f**'s up, my number is one on speed dial!) Now if he had some dry Imco's or tube Stellings, or something of that nature, I would have picked something more aggressive. But he don't. We don't even have the CMI's that Heavy may have thought. This boat still has the factory Mercruiser HP manifolds, with the merc S/S riser/tailpipes. So obviously this stock exhaust system did not work well, with the captain choice running through the prop, and trying to spin that big .660 lift, .290 @ .050 soild lifter Reed cam! Like Heavy said, these engines were the classic case of "how not to build your engine"
Mark

Mark, I agree with you 110% on that exhaust issue. I was'nt aware of the kind of exhaust he's running. I just assumed that he had a good aftermarket exhaust like CMI's or Stellings. Usually when someone tries building some bigger than stock cu.in. engines, they're running a good flowing exhaust to start with.

Can you talk him into some exhausts???:D

The CMI's are something else that the boat was advertised with and didn't have. I had CMI on the brain from reading all the Trick Marine posts and typed it in the description without thinking or realizing it for the second time now. It would be great to have CMI's, but considering the type boating that I do and what they cost, I would like to get on the water 1 time with the boat before I dump another 7 grand.