575sci HEADGASKETS AND WHILE I'M IN THERE???
 

This past summer I picked up a 2001 Profile cat with 575sci and Bravo XR drive. I am very impressed with the performance for a single in a boat of that size. I plan on changing the head gaskets out to cometics but...while im in this deep I am thinking cam change. What would be a good off the shelf grind for this motor? I was thinking of the crane 741??? Is there a better cam for a supercharger motor? Any suggestionw would be great.

The mill has 200hrs on it. Is there anything else in the upper end that should be checked out while apart? I plan on having the blower checked by Darin Meyers rite here in MI.

I am also on the verge of cranking up the boost. The question here is what path do I take???

Option 1
I could do the AZM boost kit.

Option 2
Buy a smaller pulley, A1000 fuel pump + regulator, change the 140 thermistat to 120 and go with MSD ignition.

Option 3
Try to sqeeze a whipple intercooler under the hatch along with the pulley and MSD.

Option 4
Add a superchiller and modify or replace the hatch along with the pulley and MSD.

Anybody have any suggestions appreciated.

1st. You should have Blower Shop rebuild and update the bower before you do any of the above.

I will not be using the Blower Shop but the blower is going in to Darin Meyers here in MI. I know the back bearings are a problem on these.

Used them both. I prefer DMPE for quick turnaround, service, pricing, and less frieght. Not a knock on TBS. Just bought a new billet 871 from them. Their emphasis seems to be new product sales VS service on "other" manufacturer's blowers.
Jeb, you can also pick up some efficiency by having your 256 teflon stripped at DMPE. It is not from the factory.
I would try the AZSM boost kit for starters, and rebulid your blower. See how that does. If you need more, an intercooler is an easy mod. With the cold water you have in MI, I think it would help a LOT. You will lose a little boost with the intercooler, and can then go to a 3" or 3.25" pulley. 4" is stock, 3.5" comes with the AZSM kit.
When you have your heads off, have them checked out by a good performance shop. The cam can be upgraded, but with that low 7.5 compression ratio, it may not help that much. I regulary turned my stock cam 5500 with no problems. I would wait until you can upgrade to 8.5/8.75 CR, and then add the cam. The stock cam is a flat tappet, so a 731 or 741 or Merc 525 hydraulic roller is a nice upgrade.
Regards,
Steve

Hey Steve,
Was going to PM you on some of this since you have been thru it. The blower will definately be getting a good treatment. As far as the AZSM boost kit I know they raise the rev limiter but what else do they do??? I believe someone has been in the ECM as I can wind 5500. I may be wrong but I think the kit might be a little overpriced for the goods. The parts are less than $500??? For the given HP gain maybe it isnt that bad. Anyway, I would love to intercool it but the reality is I am not sure of the space as of yet. I will have to get some clay and go measure it in storage. I think it would definately help in hotter weather.

Jeb,
The Whipple is 1 5/8" taller than stock. Most of the "bolt between" models are around 4"s.
The W256 will make some boost, but it starts getting less efficient the faster you turn it, making more heat. That's where the intercoolers come in. Our water starts out cool in the spring (60s), but gets bathtub warm (80/90s) in the summer. I think you would defnitely benefit with IC with the cooler water in your neighborhood.
If you are turning 5500 (have you checked your tach against a Merc/Rinda tool or shop tach for accuracy?), your ECU has been modified. My stock ECU would rev limit @ 5300.
Regards,
Steve

Thanks for your feedback Steve. I like the low-profile whipple but it may not be low enough. If I have to modify or replace the hatch I will most likely do the Superchiller...just need to get into storage and take some measurements. The HP loss in warm water on warm days was VERY noticable.

Do you know what else AZSM does to the ECM other than the rev limit?

I'm in the process of installing the Whipple kit now on my '02 TopGun. Didn't want to modify the engine hatch. Only 100 hours on the boat but I found some signs of the intake gasket failing at the rear water passages. Thinking now I better go ahead and change the head gaskets while I'm in there. If I go that far guess I should go with new valve springs especially since the Whipple Kit reprograms the ECM and raises the rev limiter.

The quality of the Whipple kit is really good. A few items were missing but Dustin and his guys took care of it imediately. Dustin follows up and is very reponsive to questions. THANKS DUSTIN:cool-smiley-011:

Blowers are going for a freshining too.
Am I missing anything else?

How much HP gain do you get from the:
3.5" Pully
3" Pulley

I have both, but haven't tried them yet.

Bill,
Are you running intercoolers?

When I got my boat it had the 3.5 pulleys and the GPS recall had 95 on it (probably a strong current and tailwind that day). I went back to the stock pulleys and have only run a best of 89 but can't turn above 5000rpm. Thinking the intercoolers will wake it up and work with my props. The Whipple kit comes with a 3.25" pulley.

On what-to-do while you're in there, I'd throw a new set of valve springs in.

Pick your blower/intercooler/etc., then have a cam ground by Clay Smith or rmbuilder to match your combination exactly.

Probably the best bang for the buck is the chiller on your existing setup. The Whipple is nice but $$$.

They definitely tweak the fuel curve and get rid of that annoying high rev on warm start. Also, no more black transom. Merc has these motors set up really fat. My kit also came with a low temp thermostat (a good idea with iron heads and more boost to prevent detonation), 3.5" blower pulley, and MSD 6M spark box. The rev limit on mine was 5600. A friend's is @ 5700, or our tachs may be off a little.
There is some HP to found on a SC motor (particularly the low compression 575) just by spinning it and the blower faster (more boost with more RPM = more HP).
As mentioned earlier, run the FelPros or Cometics, and check the heads (valves, seats, springs, retainers, surface) while you have them off.
Steve

After adding the Whipple to my 575, it was definitely much stronger, and picked up acelleration and 3 MPH, even though I lost 2PSI boost (was 6, then 4). I figured at that point we were on to something:D. I trien the 3.25", picked up 1 more MPH and showed 5PSI. I put the 3" on and got back to 6PSI intercooled, and a gained a total of 5 MPH from the previous non-intercooled 6PSI 3.5" set up. This was in cold weather when the intercooler was at it's most efficient, but my boat was much more consistent than it had been in the past, even in warm weather and water.
Here's a pic.
Steve

Any recommendations on springs?? Use stock Merc?

All a Merc spring will accomplish is a faster lightening of your wallet. Any good spring will work.

I have read comments recently about some ultra-high-end springs and their unsuitability for use at extended low-RPM. Don't know why but they're rumored to have failed in these situations. Unless you're running .700+ and big RPM, there's no advantage anyway. The secret is getting them in at the proper installed height/seat pressure.

Hey guys, I have really enjoyed reading your post. I hadn't visited OSO in a while, but w/ the season approaching I figured I get back in the game.

Here's my experience w/ 575's: I have a pair in my 35' Lightening w/ Super Chiller's & aluminum Merlin’s. 1st of all I was new to blower motors, so I can tell you to go thru the blowers every 150hrs. Positively no more than 200 hrs unless you want to ruin one like I did! Secondly, watch the head gaskets. This is all stuff you have covered but I ruined a motor at 281 hrs because of a gasket failure.

Here's my question for you: Now that I have added the Super Chiller's, when the motor is cold and I am idling out of my marina (this takes 4-5 minutes), both motors load up real bad. I'm assuming this has to do with fuel puddle'ing on the top of the intake. When I go to take off I get BLACK smoke out of the exhaust and it takes a second to clean up. I have to change spark plugs with every oil change now (25 hrs).

I’m thinking the Whipple’s might have been a better choice. I didn’t want to flip the coin for them but considering it is a fully integrated intercooler and intake, it might flow smoother, instead of just dropping the fuel on top of the intake.

Any thoughts/suggestions??

Quaid,

2-things come to mind. Did you have the ECM remapped? Whipple leans out the mixture. From what I have read Merc programmed them on the rich side to be conservative.

Are you pumping water through the chillers at idle or do they pick up the water under way through pickups? If you pump water through the chillers it will cool the intake too much at idle and run rich.

Good luck and let us know what you find out.

Woody

Woody,

My ECM's are not reprogrammed but yes, I did use pick ups.

So Merc has the motors fat at idle? I could see them being fat at WOT but why would they make it fat at idle? Before I added the Super Chiller's it never, ever did anything like this before. I would change my plugs once a season (100 hrs).

Should I also swap to an MSD ignition system as well?

Who should I use to reprogram the ECM's? Teague sold me all of my parts and never mentioned reprogramming the ECM's.

Good question. Not sure if it's only and WOT or throughout. ASM, (Arizona Speed and Marine) would be a good one to ask. What does Teague say?

I haven't mentioned it to Teague yet. It's something I just dealt with last summer and kinda forgot about it over the winter. I'll give him a call today.

Nope.

I can get 92.9 w/ stock pulley. Was wonder what I can get w 3.5 & 3.25 pulleys and larger props. . . . .:cool-smiley-011:

OK 575 guys...change your head gaskets! My mechanic called me last nite and said that he has seen known leaking/blown head gaskets that looked better than mine. 2001 575 with 200 hrs. I went with the Felpro 17048 gaskets for now and have plans for more extensive upgrades this fall.

He also said the blower oil was way thin and black as hell. Must be time for a rebuild.

Reminds me of what Larry at Larry's Engine and Marine in Tucson said
when I brought in my 575 heads. I brought them in for a routine freshening and he said he thought I brought them in because of the blown head gasket. He never even saw the gaskets. He just saw the combustion leaks between cylinders. I only pulled the heads because one cylinder on each engine just failed leak down test. They were basically running fine except for some unrelated fuel system issues (which turned out to be mucked up filters).

Pesky Varmint

I had leakdown over 20% on 2 cylinders last year. Merc says 30% is OK. I personally think that is a little high but when I get the boat back I will be checking it. I bet it gets better.

I learned the hard way on the 150 hr blower service! If your little 256 blower has over 150 hrs get it in and have it gone though! 204 hrs blower is seized. I would also recomend changing the blower oil every 30 or so hrs. Maybe everytime you change your engine oil?