I am considering installing a different cam in my Merc racing 575 SCi. I want to move the torque curve to achieve max hp at about 5800 - 5900 RPM. My rev limiter is set at 6000.

I am a little confused with all these sales guys trying to sell me wimpy cams -- I may be wrong but I thought i should be hearing about cams in the mid to high 260's @ .050 with lifts in the .620+ range.

Why am I hearing all these little 230 240 numbers ?? These are what we use in tractors to plow fields with, not to make top end power.

I have built a few injected alcohol motors in my day and if we ran big tracks and wanted top end power, we put in the bigger cams to move the torque curve out further in the rpm range.

With boats ----- it sure seems like thats what we need. I don't care about my hole shot and I can't believe there would be much difference between a blown verse NA motor.

Can anyone help clear this up for me ???

Message RMBUILDER. He is the cam GURU on this site. 585-654-8583 is his number. Bob Madero.

Whatever he tells you, you can run with.

Remember that with the long duration you are talking about, you set yourself up for reversion issues with the wet exhaust.

Call or email Bob RMbuilder. He can make you whatever you want. Have all the details of your engine before you contact him. I have a thread on "Roller Cam Upgrade" if you would like to check out my project. Here is his email [email protected]

Call Dean Gellner ( Mr Horspower1, here on OSO)

He's done several 575 build ups.

He's doing heads, cams and ecm mods for my 575's
right now.

He's got a good recipe to get more power out of them.

His # is 216-398-8500

The reason the cams seem small, with a lower RPM blower motor a larger cam ends up bleeding off boost from the blower and loosing H/P...Rob

A hyd roller in the 235-245 duration and .620-.640 range should put you right whare you want to be.

Call Bob. Nuff said.....

+1

This helps --- I will be making some phone calls now.

I will also check out your project jeffswav


thanks everyone ---

Why am I hearing all these little 230 240 numbers ?? These are what we use in tractors to plow fields with, not to make top end power. [/QUOTE]


Git er done ! Still have a few hundred acres left to turn over if you want some break-in time !