Peak Power on 330 Mercruiser
 

I wondering what rpm peak HP is made on a 84 330 Mercruiser. The motor is stock as far as I know. Where should I set a rev limiter at?

Thanks Rob

set it at 4500

BOY DID I MIS READ IT WAS A 330 NOT 365 ,,BRAIN FADE ::(

SAVE THOSE ROD BOLTS 4500 ,,

set the rev limiter whereever you want, but keep in mind that engine is not designed to be run over 4600 rpm. the main reason being that the rod bolts are not meant to handle the acceleration and deceleration and subsequent induced stretching and compessing of the piston and rod assembly over 4600 rpm. as they stretch out of spec, the rod bearing will move in the rod and eventually spin or worse. also , and this will probably happen first, you're beating the **** out of your valvetrain over 4600. those ****ty little single springs just aren't up to the task, an dthe valves will float and eventually hammer the head off a valve even thoght you don't think you hear the floating. but then again, there always someone who gets away with it! hope this helps.

That engine has cast pistons that will crack at sustained rpms above 5,000. The mags can be reved higher.

I think Cord means( may crack) not will crack mine run 5100 all the time,but then again I have ARP rod bolts.

wow maybe this motor has been apart. When I bought the boat it had a 15p al prop on it and the motor spun at around 5200 all year long. I didn't know any better. Then i started to try an figure out why it was so slow and changed to a 21 prop rpms dropped to 4200 now. I m considering buying a 19p prop to get the rpm back up to 4600. I have ben told this would give me good performance. But now I'm concerned rpm might be too high. I dont think it has a rev limiter at least I never hit it. I'll have to get one and set it at 4600.

Thanks guys.

Rob

you don't have to get a rev limiter. just pay attention to your guages evry 20 sec. or so, and prop it out right. also you should really think about replacing that poor old engine! great idea, since i'm not paying!

This will be the last year for this motor. But its been running so good I hate to touch it. I think it has about 500 hours on it now. I'm just planning on rebuilding it and upping HP to 400 maybe 450. I want to try and keep it reliable, lower comp. so I can run any gas. I don't want to start having drive problems by going too radical. I hear the TRS drives are ok till around 500hp.

with a good trans, and if you don't abuse it They'll handle more than that.

Yea I don't really want to sink that much into this boat though. I will probably sell it soon for something a little bigger with twins.

Rob