WETTE VETTE

RLW - use the 325's!!

JimV

iTrader: (1)

Mad Max

I have wedges for the Merlin VR and GM heads although I wouldn't recommend either one if your starting fresh. The Dart iron heads would be my first choice. They are capable of flowing as much air as their aluminum castings.

KAAMA

iTrader: (1)

Lift on the Ultradyne was .601"/.601"

Lift on the Crower is .610"/.609"

I did NOT dyno the engines with the Crower cams. Another thing about the Ultradyne's is they have a much more AGGRESSIVE opening and closing ramp speeds.

I never water tested the boat with the Ultradyne's as I removed them and installed the Crower cams.

Keep in mind that I used a 1.8:1 ratio rocker arm on the intake side of the heads---1.7's on the exhaust.

My guess is that swaping from the Ultradyne's to the Crower's I may have lost 8-15hp on top-----just a rough guess. Like I said before, I could care less about the power loss when I switched to the Crower's. I just want the engine and compoments to live. Because of Ultradyne's aggresive, fast ramp speeds, they are very HARD on the valve train---something I did NOT want.

Some guys want every DROP of HP they can get out of an engine i.e. bigger cams----even solid rollers, high comp ratios, etc. My attitude is a little different. I like decent, mild idling engines that shift easy when you're trying to dock/slip the boat, or when the WIND is pusing you around, or when you're having to deal with the water CURRENT of a river, or when just manuvering around other boats whose captain's don't always know what they're doing or half in the bag from drinking, etc, etc. It's these kinds of situations that you can find yourself in that can get you into trouble FAST and a boat that idles well and does NOT die when shifting is what I prefer. Some dudes have such a HUGE, LOPEY IDLING CAM in it that it dies everytime he attempts to shift it can get pretty intense---especially when the engine dies and he's still coasting in a direction he no longer wants to go in and then when he starts the engine back up he usually over compensates each manuver cuz he's panicing then he runs into another boater or into a sea wall----that's when a guy doesn't look so cool anymore.

With those Crower cams, Crane Fireball Hi-6M ignition boxes, 950 Holley's, Dart single plane intakes, and MSD Crank Triggers, the boat in gear idled as low as @550-600rpm with a 32' Active Thunder and 32" pitch Bravo One 4-bladed props. Works good for me.

Nordicflame

iTrader: (4)

Mark,
was the cam in this thread actually the UltraDyne?

http://www.offshoreonly.com/forums/s...threadid=58079

Post 9
That may explain why it was still making power when passing the 5700 rpm mark.

Thanks,
Dave

KAAMA

iTrader: (1)

Dave, to answer your question; "YES" it is. It was a difficult decision because of the costs involved, but I wasn't sure it was a good idea to run a dual pattern cam---so I went back with a split pattern cam---I must have changed my mind 15 times on which cam design to go with. The split pattern Crower was either going to help me or hurt me, but whatever it was either way it would only be by a very small margin I figured. Heck, I was even considering some flat tappet Ultradyne solid/mechanical cams----I still have those new in the box with Crower cool face light weight lifters.