engine water ingestion, what am I missing???

[mr.fixitman760]

Last season my ss900 ate the front rod bearing and blew out the case, not bad, just a small hole that I had my production welder friend fix, he did a fantastic job but just as a precaution I also filled in the inside with JB weld and sanded smooth. Ever since the rebuild I cant seem to keep water out of the cylinders, every time I pull the power valves out they have slimey oil gunk on them and beads of water on the valves themselves and the head domes show it too, turns out the chamber was cracked, sent it back to pfp and got it fixed, ski instantly ran 100% better, valves still sticky... still getting water in... changed head orings, thoroughly sealed the head, pressure tested the chamber again, dried out the waterbox (baffle isnt broken either) and my air filters arent getting wet either.
Am I missing something????
This weekend I also lost my front piston which im assuming was caused by water since I cant find any other viable reason.

 

[N3vrSat1sfied]

Pressure test the cooling system on the engine. Possible crack in exhaust manifold. Should hold 40-50psi no problems.

I just run the two head exits together, Manifold hook ups to air hose inlet and the other to gauge. Cap off water injection if using.

 

[mr.fixitman760]

Pressure test the cooling system on the engine. Possible crack in exhaust manifold. Should hold 40-50psi no problems.

I just run the two head exits together, Manifold hook ups to air hose inlet and the other to gauge. Cap off water injection if using.
View attachment 341468

doing that first thing tomorow

 

[N3vrSat1sfied]

Could be as simple as exhaust manifold gasket. I had an issue before so I just started checking cooling system, pipe chamber, and leak down before I put an engine in (or anytime its out)


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[x2mafia]

Could be as simple as exhaust manifold gasket. I had an issue before so I just started checking cooling system, pipe chamber, and leak down before I put an engine in (or anytime its out)


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this^^^
just had this discussion with @tntsuperjet literally today. Pipe starts scarfing out the fuel and throws water vapor directly into the cylinder.

 

[tntsuperjet]

Dam that engine has some serious heat in the pistons.
I think your never gonna get it to live a full season you keep having black pistons like the good hole has.
Pistons also look like they maybe hitting the head.
Have you checked the squish??

 

[Christian_83]

What the above guys said, pressure/leak testing.
I pressure test my engine, when i get a brand new engine and also i have haft engine apart or exhaust manifold apart.
@tntsuperjet what do you mean cause this heat? lean carb or to little cooling?

 

[mr.fixitman760]

Dam that engine has some serious heat in the pistons.
I think your never gonna get it to live a full season you keep having black pistons like the good hole has.
Pistons also look like they maybe hitting the head.
Have you checked the squish??

Disregard the engine bay photo, lighting was bad, the good piston is a nice brown color, neither of them are hitting the head, the piece of piston that blew out of the front came back up through the port and got smashed a few times before it died

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[DAG]

Has your riding style changed aka learning new tricks sloshing more water around? These helped me alot when learning backflops. $150 if interested

 

[sjetrider]

Has your riding style changed aka learning new tricks sloshing more water around? These helped me alot when learning backflops. $150 if interested

These are awesome, Just not sure they get enough air for 48mm+ carbs? Any difference going back to open FA's, run leaner? I REALLY wish I could feel comfortable with them on my new 1135, I would buy them in a minute, I run these FA's on my 760 with 46's

 

[mr.fixitman760]

Has your riding style changed aka learning new tricks sloshing more water around? These helped me alot when learning backflops. $150 if interested

The way my air intakes are baffled I really don't take in much water and if I do it goes right out, definitely not soaking the filters enough to do this much damage

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[sjetrider]

A few things can cause this water ingestion, assuming its not just from getting water thru FA's (which you said your not).
Exhaust mnfld gasket, cracked inner PFP chamber (which you said its not) WB baffle which you said is good, compression O-rings which you say are good. And then the less obvious and difficult to see, internal crack in exhaust mnfld, Internal crack Cyl between cyl and sleeve, sleeve gap between Cyl and sleeve (you will think this is crazy but I have had a sleeve in a billet cyl where the sleeve shoulder was bored slightly off what the sleeve bore was and sleeve was forced into shoulder causing a gap between sleeve and billet, this caused the crank bearings to wear FAST due to slight water ingestion at top of exhaust port continuously. The water came from top of sleeve between the billet thru barely visible gap, didnt notice until I had to remove the sleeve and you could see where the sleeve never touched the cyl in that area.
So check all other stuff then slide sleeve out and check for cracks or gaps, it will be visible with sleeve out if you have an issue like this.
look at the sleeve and Cyl pic attached for clarification
you can see where water came from top of sleeve into top of exaust part. This motor ran pretty well but murdered crank bearings.

 

[sjetrider]

the cyl is anodized black so that is the color difference for anyone wondering

 

[tntsuperjet]

Disregard the engine bay photo, lighting was bad, the good piston is a nice brown color, neither of them are hitting the head, the piece of piston that blew out of the front came back up through the port and got smashed a few times before it died
Ok so I’m not the typical guy that looks at the surface.
When I asked what your squish is it’s not because I see the smashed piston chunk in piston, it’s because I see a faint line 3 mil wide around the outer edges of both the good and bad piston.
You should be able to see the transfer ports blow pattern cleaely in the piston and they should have no color on outside edge.
Can only see a wash pattern faintly on outside edge of rear piston.
I would say you water coming in through your open dec cyl through your sleeve. When you blew it up you prob egged the sleeve and it opened a cavity into the exh port.
Or you have detonated the motor hard enough long enough to open the whole top of sleeve into alum sleeve bore.
You gonna keep doing this if you do t stop the det!!
I can see by your pistons your heavily reverse jetted and you have over 32 deg timing
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[mr.fixitman760]

The ring your seeing is the piston itself, it's a perfect machined circle, the port wash is much more clear on the rear piston but the tops of these also have a black coating on them from the factory as do the old pistons from the first blow up, as I mentioned the pic I posted is sub par and light is bad, reverse jetted but not heavily, and XS wanted 34°static timing

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[mr.fixitman760]

Hooked up the top end to tie garden hose (water department said we have 55psi at my shop) found out it's leaking through the exhaust gasket, very slowly but it is seeping through, gonna true up the surfaces and retest

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