Merc 575SC motors..
 

hey guys..

i did some searching on the forum but most of the finds were really old (2004 or older).. i'm looking at stepping up from my 23 baja 496mag to a 35 or 38 footer but i can't deside on the motors..

i know the 496 motors are turned key and with reg oil changes and services they could last a long time.

BUT i want some power and i love that Blower Sound :D.. so i want to know what type of maint i'm looking at with the older 575SC..

do they need the services like the 525 (valve jobs after 200hrs).. how is the service on the blower it self? What else should i have to worry about??

I guess i would have to run 91 gas and not 87 anymore, so thats a cost increase :( but will worth it...

thanks everyone..

mike

I have approx 330 hrs on a pair of 2002 575's
So far, they've been flawless.

Neither uses any oil between change intervals.

They have a flat tappet hyd. cam, instead
of a hyd roller like the HP500',EFI's,525 EFI's
so, the valve train doesn't take quite the beating
in does with the latter.

The newer B&M blowers have had some rear bearing
failures reported.

The only thing I've had to do different maintenance
wise, is to change supercharger oil in the front
and back reserviors.

I'm replacing the head gaskets this spring
as part of preventative maint.

Others will mention blower rebuilds at X hours.

I love mine, and would have no problem owning them again.

JaayTeee thanks for the post... thats the type of info i'm looking for.

ANYONE else out there have some input??

thanks,
mike

Yes they are awesome! Idle like a kitten (cmi headers, very loud)
No load up, very well mannered.
Blowers are weiands so they are fine, no they dont eat XR drives, they are perfectly mated with the xr's
the best is that they are injected not carbed so the computer is always compensating so that no loading will occur.

They do idle a little higher than a normal carb motor, around 800 850 or so but believe me they are just flat out impressive.

They will use about 5% more fuel.
The thing to look for is to make sure the front seals on the blower pulley's are not leaking oil. Early models had issues with bad seals. Check the repair history, it is likely that they have been replaced. Also have compression and leakdown test done. On leakdown, Merc says anything under 30% is ok by thier standards. I would be leary of anything over 15%.

So far they appear to be a rock solid turn key motor. Only extra maintenance is to change blower oil about every 50 - 100 hours.

Once you run these, you'll be hooked. I was VERY skeptical about blower motors, but since this is a very mild Merc engineered package; I am now comfortable.

Also, Scott Buteyn of Mercury Racing was here checking out Nauti-Props' boat and doing some field testing. I got to spend quite a few hours talking with Scott about the 575 (and others) and any issues that Merc may have experienced with it. Basically it is a VERY sound motor. Scott said that head gaskets should be replaced about every two years and "check" valve springs about 300 - 400 hours.
As far as rebuilding or refreshing them???
Any engine that has been run to death will have to be rebuilt NA or SC'd does not matter.

575 sci is good easy for however long you want it to last which depends how hard you are on it. You should see 400+ hrs on it if your really thrashing it, or 600-700 if you baby it and take care of it and oil changes constantly, keep an eye on everything all the time and dont run it WOT for 95% of its life.


Go for it, you'll be glad you did.


Also, pull off the thermostat housing and check the small hose passages. If they corrode easily.

From the research I have done, they are built like a brick s**t house. Should last a very long time as long as they are properly maintained.

WOW :) thanks BillR...

what are the years that these motors were built?

i'm looking to get into a 38 Lightning or X with these motors.. how is your insurance with your Cig compaired to a Cig with NON-blowen motors..

thanks,
mike

Good engine package and very easy to upgrade to 725-750 Horsepower!

(can't see the photos) thanks anyway..

Are these motors are Forged? crack, rods and piston?? are the only things weak are the head gaskets?

whats the MAX you can put out on a stock internal motor (700 or 800hp)

The factory engines have steel forged cranks, Manley H-Beam rods, and JE forged pistons. The rods are a press fit from Mercury and we bronze bush them in house for full floating pins. These components will handle 750 HP with out an issue.

Dean,
Will the stock fuel system support those kind of #'s ?

JaayTee,

Have your motors been worked or are they stock 575's? What kind of speed do you get out of your outlaw? Thanks