If you don't have oil temp guages, get them. Having the oil heat up and thin out is a major cause of engine failure with this kind of boating. Back off at 260, measured in the pan.

This is the primary reason for a good synthetic motor oil.

Probably the hottest part of a motor for motor oil is when the crankcase oil splashes on the bottom of the pistons. A conventional oil is IMO not up to this extreme.

I bet if you ask most of the offshore racers on the APBA circuit, they would be running syn oil.

It all comes down to an oils ability to prevent shear and prevent metal to metal contact. IMO

What size and type of engine is the thread starter referring to?

That makes all the difference in the world.

Just re-read the thread. With 625 horse I wouldn't be worried about floggin it for a long period.

It's like anything else, if you drive it like you stole it, you're gonna have to rebuild it quicker that's all.... higher rpm, higher temps, higher cylinder pressure, inertia, more revs on the valvetrain... etc. etc. = faster wear.

x2

Till your out of fuel!!

What kind of speed are you running in a 24x7 with 625? That motor has to be barely working to push that light ass hull. My buddy has a 25 aggressor which is basicly the same boat and he has a 330 HP and he pegs the limiter every chance he gets for as long as he has too..

Yes and no... when I change mine it comes out looking like I just put it in (every 15-20hrs) I use NAPA and can do it for way less than the synthetics. I don't rely on my fluids. I maintain accordingly.

The way an oil looks is not a good gauge. Dirty looking oil only tells you that the oil is doing its job.

The topic was in regards to WOT for long periods of time. Unless you are running an oil cooler or even if you are any type of oil breakdown is going to rapidly increase internal wear.

Not sure how NAPA oil is going to compare to Amsoil Syn or any other syn. High performance engines require a high performance Syn Oil for High Rpm WOT operation.

If you are running Conventional Oil, Yes you better be changing on a regular basis because you can never be sure on the degraded protection around the 20th hour??

IMO conventional oil is only good at best for breakin purposes only, and then switch syn to protect the investment.

Boat runs low 80's, so far. Still have a few things that I want to add though. Fun boat!!!!!