575sci Head service
 

Looking for info on the 300 hour head service... the hubby is curious what other people are doing... valve seals, springs? Or complete new valvetrain... any ideas?

I rebuilt a pair of 575SC's last winter with about 300 hours or so. I planned on replacing the springs, upgrade to 10* Titanium retainers and 10* locks. The surprise was the valves were starting to tulip, so ended up replacing all the valves. Before Crane went out of business, ended up replacing all the rockers as well.

At a minimum. replace the springs, retainers and locks(10* steel) and seals. I don't see a need to go to titanium retainers. The problem is the market is flooded with cheap import titanium retainers for around $200.Good titanium retainers will run $300+. You just won't see any benefit in a 575. It's just not worth the money. As far as the valves, that depends on how they look. As Vinny said, he replaced his because they were on their way out. Just wait to see what they look like. Hope this helps.
Eddie

What needs to be done will be determined after the heads come off and everything is checked. Minimum would be valve job, seals, springs and retainers.

Eddie,
I agree, Titanium retainers on a hydraulic cam are not needed. However, after spending soooo much money on rebuilding everything else, I figured why not get Titanium. In any case, 10* locks are definately a good thing to add. Personally, I dont see why Merc ever used 7* locks.

Thanks all for the info... thats what we are planning to do... plus blower service since they will be coming off... BTW, which are the better blowers...weiand or Holly? Our has holley stamped on the rear casing...

both are made by the Holley corp. now, only diff. is the holley
(B&M) HAS teflon stripped rotors, while the othert doesn't.

sonicbunny the blower on the starboard side was just rebuilt by the blower shop before he lost the boat.

The earlier 575s had Wieands, which were slightly better than the B&M version. The difference being front and rear oil bath bearings. Only the front bearings are oil bath and the rear bearings are sealed on the B&M. Either way the bearings are prone to fail.

I could not agree more. You will never find 7* retainers in my shop. The point I was trying to make about the titanium retainers is to watch the imports. There are some cheap ones out there. It definitely can not hurt to go to titanium over steel, that's for sure.
Eddie

Eddie,
If you dont mind.. drop us a PM on price for the valve springs, seals, and retainers? We will be pulling the heads off in the late winter then know for sure what is needed.
thx
amy

give Jim Valeko a call 616-889-0928 hes right close to you and you'll be glad you did .... Top Notch all the way

Will do.. thx

Have the heads crack checked first.

That may change your mind on what you do.

All 4 of mine were cracked in between the seats.

Will do Amy. I will send it in just a bit. Thanks,
Eddie

I went with Alum heads on my rebuild 575s

If you are set on using the cast heads and the valves somethings haven't been mentioned: I would check all the valve stems for wear, I then would measure the clearence between the valve stem and the guide, which is as cast into the head. If they are worn I would stay away from guide liners and go with a solid bronze guide that has a step. I would run .0015 clearence on a 3/8 valve on the intake and
.002 clearence on the exhaust with a teflon seal with the steel ring removed from around the valve stem. If your valves are worn or you replace them then you can go to 11/32 valves since your'll have to replace the guides anyways. I would inspect the valve seats for cracks or corrosion pits to insure the valve job isn't going to sink the valves into the heads. seats are from 4-6 $ each labor varys, guides are about $18 -$20 each installed.
I believe all of our Ti, is imported now either from Russia,or Japan, it varys on which material spec is called for by the manufacturer. The material is also cerified and has to pass test. C.V. Products certifies all of its material in-house. The days of retainers at $100 are over with. I would leave the retainer up to the engine builder or someone like RM Builder, to decide for you.

When rebuilding these heads, does everyone go with mercury parts or aftermarket? We've heard that mercury cost more $$$ with the same reliability as crane, ect....

Go aftermarket. Merc. isn't making any of these parts. All they are doing is marking them up. You can buy better parts for the same or possibly even less money then if you bought from Merc.
Eddie

Sonic bunny,
Not to steal your thread or anything, and I'll be watching this thread with alot interest, but I have a HP ?

How much Reliable HP can made from the Mercury 575SCi and still run 93 octane?
thanks,
Dean

Mine are a little under 650
and OH HE!! they sound good!

Q,
What did you have done to them and by who?
thanks,
Dean

I know we are running superchillers which is supposed to add 100HP... so just around 650HP if we are correct... There are kits available raising boost, changing to MSD blue box, and a 120* thermostat but we are quite content with a 93MPH boat... lol

SB,
That is one of the first upgrades that I would want to do myself. Great thread!:drink:
Dean

Dean Gellner's built up a few 575's that are producing
700+ hp.

He built a couple of sets of dart iron eagles,
supplied me with the custom HR cam he uses
and remapped the ECM's and mine run awesome

I'm guessing mine are in the 650-675 hp range,
being that we kept the compression stock, and
didn't use the heads he uses on his recipe.

Do you have chillers on your 575's?
Thanks,
Dean

No, don't have clearance necessary for them, and scoops
are out of the question.

The neat thing about them is that they totally
look stock....they don't sound like a stock 575
anymore though.

yeah,
I don't know how the scoops thing is going to go over with the wife and kids? But I would really like to have the chillers if I can make it work. It seems to be pretty easy 100 HP?:drink:
Thanks,
Dean

I made a scoop hatch for the last boat, the wife
and her friends hated it, and when rafted up,
the drunks, when crossing boats, seemed to like to step on them......CRACK:eek:

My only other worry ( if I were able to add chillers)
was supercharger longevity.

Simply adding the chiller usually doesnt net you
all that power, it's when you add the smaller pulley
along with it that gets you there.

These superchargers have had their share of problems,
in stock form.

Putting a smaller pulley and winging the sh!t out of them probably isn't good for them in the long term.

The 575's Vinny P. Rebuilt last winter were mine. We decided to keep them completly stock but use all the best parts. There is something to be said for a 575sci in stock form. They sound and run killer!! Will I be the fastest guy at the next poker run ? No....... But I did finish everyone that I entered and I didn't miss a day out this summer. I would love to crank them up and pull 700+ hp out of them but my season here in NYC is to short to take any chances, Good luck with your rebuild and keep us posted on your results.............. John.

Brad Smith Power in Joplin MO did the rebuild.
The only thing reused was the block and crank.
Punched out to 510, Alum heads. full roller,
On the dyno it was at 715 or so w 700+ ft lbs tq.
that was w smaller pully and REAl gas.
I had him back it down to stock pully and all I can get in OK is 91 so that is where he set it at.

I am VERY happy w the build.

Q,
Thanks for the info.

Another Q? What has been everybody's experince with the CMI headers that come on the 575's? Do you have to have them pressure tested every year, and has there been problems with them? I hope they aren't like the 525 CMI headers?:eek:
Thanks,
Dean

One of mine was leaking when I got the boat, Performance Boat brokers said they fixed. Hmmm
One was leaking when rebuild so I ordered NEW one then.
But boat had 400+ hrs when it blew up.
Suppose to of had new top end but I dont think so.
So I quess the answer is YES I am going to pressure test every year.

Q,
Thanks for your input. Seems like pain in the A$$ to have to leak check those CMI's every year!:angry-smiley-038:
Has anyone else had the same problems? I think I might just replace ones I have, (IF I buy the boat!) with some Eickert headers.
Dean

The dyno run is posted in the Grandlake/ LOTO section

That or the Stainless Marine Gen III's which seem to work great on blower engines!:coolcowboy:

P,
Yep, I agree, that would be my second choice, they are a great manifold.
Dean

When researching 575's to buy my boat, I don't remember issues with the CMI's like the 525's have had.
Mine have had no issues, freshwater only, have just over 200 hrs. now.
Have had excellent performance from mine, strong runners.

Kelly,
That's good to hear, the 575's I'm looking @ are 2001's with ~ 388 hrs, and they have been run in saltwater. I just want peace of mind that I don't have to leak check them every year.
Dean

The only thing else I've heard about from salt water
usage, is the intake manifolds corroding.

Vinny had problems with this.