525's water in oil and headers
 

ok guys I listened to you all I thank you as always the problem was the headers two sets brand new CMI headers and both pair leaked.now a new problem blow by pushing the dip stick out.I did a compression check 170-175 all eight cyls did a leak down 3% seems good.the water that was in the oil from the headers where flushed three times with a 25% mystery oil and reg oil.what will cause this blow by.the engine is running smooth.

Some engines seem more prone to it than others, We had 3 doing it after rebuilds to 540ci on a 47 Fountain. Installed springs on the dipsticks to keep them down. No real problem with the engines, I think the loading the boat puts on it just causes too much crankcase pressure and not enough venting to handle it.

Tell us a little more here. Merc HP525EFI's? or some other build out. Whose cam and detail the rest of the exhaust, Captains Call? S-Pipes, Muffler, ETC? Intergrated transom on boat with exits under the platform? Do you idle a lot, back down hard? Have you pressure tested the headers?
Not enough real info here to render a good opinion!
Water in headers that's getting into crankcase will cause a lot of painful issues and crankcase pressure can be one of them.

Regards,
Ray @ Raylar

hi Ray
third set of headers from CMI the original had a leak the new ones from CMI also had a leak finally no more leaks.the motors are stock 525's this is port motor.The boat is 2004 fountain lightening all stock yes it does have silent choice but always left on.

please !!!!!!!!!!!!!!

The boat is 2004 fountain lightening all stock yes it does have silent choice but always left on.[/QUOTE]

Left on? On like through hull or on like through the prop? Doug

Sonic 28:

Are these engines in this boat a side by side or staggered setup?

Are your tips attached to the headers a custom shape and are you using CMI's switchable exhaust or someone elses?

If you can, take some pictures of the installation and post them here so we can see the setup.

If these are stock HP525's, the CMI's are Mercury's design and they should have been fine from the get go originally. Now that you are sure the leaks are stopped, and obviously some good oil changes to get all the water out, what is telling you that you are still getting water in the engine?

Have you pressure tested the closed cooling system at about 13-14lbs abd made sure you don't have some other point of leakage?

Just some more questions to help with your investigation and hopeful repair.

Regards,
Ray @ Raylar

hi guys
the engines are staggered yes its all cmi with cmi silent choice. when I say open I mean thru transom.yes
i did do a preasure check on the closed system as well.
i beleive the water in the oil thats left was from the journals and will go away after a couple more flushs.Why and where could the blow by come from a crack in the piston when hot?could I have cracked it when the engine was hot and the water hit the piston if so why didn;t i suck a valve. When I run the boat its smooth no miss fire or skips.

















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Are these engines equipped with PCV valves? If not that should help you a bunch. Also if you have not, I would get the engines good and hot a couple times, maybe your blowby will subside.

Rings

Whoa! here boys, you guys are slinging more information at this guy than is needed or is applicable possibly!

Sonic28:

Lets get some more factual information here, 1. You say your compression test netted 170-175lbs of compression in each cylinder with only 3% leakdown, I am a little suspicious here, a brand new Mercury Racing HP525 will only have about 160-165lbs of compression right out of the crate, so how is yours higher? 2. You indicate your two HP525's are in a staggered mount whcih means I believe the port engine has the long exhaust extensions going back to the transom. I have heard that these installs without support braces at the back of the motors or along the long extensions, that the weight of extensions unsupported with flex and shake in the pipes has caused some cracking on headers in staggered installs with HP525's. I would suspect that may be why the headers cracked. Is that the side where the headers developed cracks or did the starboard short side engine headers also crack?? I was also unaware that installs were done with staggered HP525's and captains call switchable exhaust.
I could be wrong here but I think Mercury Racing as indicated to builders and Mercury Racing engine dealers not to run Captains call switchable type systems on staggered HP525 twin packages. Who put the Captains Call switchable exhaust on the installation and when was it done? I guess I should also ask how old the boat is and how long did it run before the problems appeared?
As far as damaging rings, pistons or valves, if any of that has happened, your compression should not be that good in all cylinders and especialy with measured leakdowns at 3%.
Yes you do need to get all the water and contamination out of the motors to prevent any more damage and you should check oil pressures (hot & warm) to see if any possible oil pump or bearing damage has occured from water in the oil, resulting in lower than normal oil pressures.
When you get what appears to be most of the contamination out, do an oil test with a good firm and make sure the oil tests good for water and metals. If there is any serious damage inside the motors, the oil tests after running a few hours will show high metals content above expected norms and the water will also show up in the oil tests.
Don't throw the baby out yet with the bathwater, you may have dodged the engine damage bullet somewhat, but you need to make sure you are not going to have this condition show up again and do more damage!

Just some more questions and thoughts.

Best Regards,
Ray @ Raylar

I have two different compression tester. It took me a while but I found out one always has higher pressure then the other. I just use the numbers between cylinders as a comparison.

I'm with Ray!
 

Seems very odd to have good, even compression and a very low leak-down and still have excessive crankcase pressure.

Staggered engines in a 2004 Fountain 35 executioner? Until the "new" 35 2007/2008 Lightning, everything was side by side, as far as I know.

sonic28
Bump?

Had water in oil caused by leaky intake gasket, residual water caused milk shake in oil, water and oil mix made "mud" in breathers, now no breathing, result excess crank case pressure, as a result oil forced up dip sticks, removed breathers, engine ran just fine, changed breathers, A-ok now:) ps-changed intake gaskets ! Good luck.

What's The deal?
 

No water in the 496 intake manifold, so I don't think thats the case here. I hope Sonic28 will come back on our questions and I hope we who are trying to help are not being played here on OSO!