Max RPM on a 330 merc?
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#12
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You actually put more of a load on the motor dragging it down to 4200 or 4400. You are probably in the secondaries at 3200 or 3400. At 5000 k your not in the secondaries till later maybe 3600. You can cruise at 75% throttle at 4000 or 4200 endlessly.
Having bigger motors is nice but they don't live near as long. we would burn the belts off and add gas. Pretty good boating.
Having bigger motors is nice but they don't live near as long. we would burn the belts off and add gas. Pretty good boating.
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I have a 454 started life as a 330. Have about 300 hours on it now.
Spins 4800 all day long in my jetboat. I changed the heads, cam, intake, and exhaust about 5 years ago. That really livened it up. Could probably handle 4900 or 5000 now but will need a shorter impeller. It's a workhorse and 4800 seems very safe (especially for non-forged internals), so I'll leave it like this til the motor wears out or lets go.
I think it's a good motor with the right cam, heads, and exhaust.
When it's rebuild time, you can pick up an easy 100hp with a few simple changes.
Enjoy!
Spins 4800 all day long in my jetboat. I changed the heads, cam, intake, and exhaust about 5 years ago. That really livened it up. Could probably handle 4900 or 5000 now but will need a shorter impeller. It's a workhorse and 4800 seems very safe (especially for non-forged internals), so I'll leave it like this til the motor wears out or lets go.
I think it's a good motor with the right cam, heads, and exhaust.
When it's rebuild time, you can pick up an easy 100hp with a few simple changes.
Enjoy!
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4800 is a good number. Most 330's that fail that I've seen is a result of a leaky exhaust like a riser gaskets. I suggest you change them every few seasons don't wait for them to begin to weep. Its cheap and easy to do.
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Got a buddy running stock '96 330 bottom ends with Brodix heads, roller cams, Merlin intakes, 4150 Holley's, MSD inginition, and CMI e-tops. Runs them 5K with no problems. Probably would not want to spin them much faster for any length of time.
#18
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Prop for 4600rpm with a normal load; then you'll be at 4800 real light or 4400 real heavy.
The engine will not make more power above 4600.
The engine will not make more power above 4600.
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Patrick
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That is exactly what I've done with mine. I tried 4 props before I found the one (Revolution 4b 21p) that put me in that sweet spot.