03' 575 SCI, How Reliable & Maint..
 

Hello, I am looking at a 03' boat with 575 SCI's, motors have 280 hours. I know very little, about these, and was wondering how reliable they are, and things such as maintenance, oil changes, valve springs, and total rebuilds. Any help would be appreciated. Thanks

Good motor. Most guys can't leave em alone though, and put an intercooler under the blower, change out the cam, change pulleys and do an ECU reflash for about 675hp.

In bone-stock form, they run just fine on 89 octane.

Depending on the usage, 300 hours would likely be time for freshening.

Valvesprings for sure, and if the motors have been run hard, they will likely need new valves.

Do a leakdown to determine the condition of the cylinders and piston rings. My thoughts are to go ahead and re-ring it.

They run a flat tappet hydraulic cam and there's a good 30hp there waiting for a hydraulic roller cam to unlock (more than that, if you want to give up a little more idle quality) - but any cam change will require an ECU reflash.

With that being the case, it's best to find the reflash guy FIRST and see what cam profiles he's already got a "canned flash" for. Saves money and trouble.

MC

I got 388 hrs out of my 02's before a head gasket
started to let go.

I think 03' was when they changed the superchargers to
B&M's, they have sealed ball bearings in the rear.

I've heard of more than 1 having issues with them failing.



I went ahead and freshened mine when the head gasket
problem came up, used Dean Gellners 575 recipie.
( heads, hr cam, ecm reflash)

I'm very happy with them.

I have a pair of 03 575sci motors in my Spectre. Most durable set of motors of have owned so far at 180 hrs. Most owners put head gaskets and valve springs and blower rebuild around 300-400 hrs. Merc HP says to do leak down check every year to determine what maintenance to do. My friend waited too long to do head gaskets over 400 hrs and had to buy a new block on one of them, burned a groove across 2 cylinders when head gasket blew. He is rebuilding blowers now at over 450 hrs due to rotors touching each other. A lot of the preventive maintenace depends of how they were run and taken care of by previous owner. Its alot cheaper to do the preventive maintenace than wait till it cost a whole lot more to fix other damage. Great motors and more HP potential when taken care of. Make sure leak down and blower inspection is done before purchase. And then do other listed maintenace as soon as possible. Search 575 sci for more info. Call Merc HP for expert advise 1-920-924-2088. The Bower Shop in Ca is a good place to get blower refresh. http://www.theblowershop.com/home

Plan on at least valve springs and seals. Changing the head gaskets at the same time is a really good idea. You can do the springs without removing the heads.
Check the blower out really good. Keep up on the oil change in the blowers. The oil will get diluted with gasoline and thin down drastically. It really should be changed every 25 hours or so to be sure it's good. If you feel any sticky spots in the blowers, pull them and have them rebuilt. Darrin Myers is the best bet for the blowers. They do excellent work and are very reasonable. I think a rebuild is around 600-700 per blower.
All in all they are great engines. Keep up on the maintenance or it will cost you in the end. There is definitely some power left on the table with them. Good luck.
Eddie

At 280hrs I would plan on a head gasket change (if it has not already been done). My gaskets were gone at about that time and the engine was in stock form. I would also recommend a blower rebuild with DMPE (if it has not been done). The mechanical fuel pumps are known to self destruct also...I dont think it is a problem specific to the 575 but it happened to mine. They actually hold gear oil in the housing that seems to get neglected and never changes. Also, dont run them out of gas. I have a theory that when you do, the motor will pop/backfire through the blower knocking the rotors out of time. I am pretty sure thats what happened to mine.

BTW...In my experience everybody's info seem to be good in this thread.

all good advice above.......as said before do a search and you will find lots of threads about them. That being said I LOVE mine......I did rebuild mine from top to bottom prematurely just because I wanted to be preventative and know what I have......They are great platforms to had some serious HP but my choice was to keep them bone stock......I like the reliability and I hate to lose a single day in the short summer we have here in NY.......the only thing I question that was stated earlier was running them on 89 octane.....my engines and svc. book clearly state 92 octane.....I run 93 because that is all I can get . I have heard of guys who will put 89 for emergencies only and will take it easy till they get 92 in the tanks......good luck.........

John,
Although as far as the hour meter goes, we did rebuild yours early. However, remember what we found when we tore them down. The valves and seats were beat up, the pistons were a bit loose in the bores, Merc uses that not so good metric ring package, the intake manifolds were about ready to rot through the water passages. From what I can remember, everything else looked fine, even the head gaskets.
All told, I agree they are good engines. With a rebuild by someone who knows engines, they can be great engines..

Thanks everyone for the info.. This is what I love about OSO, all the people willing to help. I did, do a search on here, before I posted my thread, but did not come up with alot of info.. Supposedly, the owner is meticulous about the maintenance, and the care of the boat. Dealing thru a broker at a marina, and not getting much help from them. Thanks again everyone, and I will keep you posted.