Blue by You

My new 540 Motors are in and it runs GREAT…except for the water getting in the top end at higher RPM’s. It’s not a lot…just enough for the breathers to spit. <10 minute idle and it’s gone. I think it’s reversion, but the builder thinks it’s these brass plugs in the heads that are not expanding as fast as the aluminum heads do under pressure & heat and are letting water in. Motor's dynoed at 808HP at 6000RPM but the water seems to come in just before 5000. Regardless of oil temp (220 degrees) He’s changing these plugs right now and will test today. Happens to both motors at about the same exact time. We pressure tested both motors to 40 & 70PSI for 20 minutes…no leaks. We do know that we have water at the clamp holding the tails onto the headers…we had a bad gasket that leaked on one side at idle, changed that & leak is gone. So this is why I’m thinking reversion. The only part I don’t get is that the plugs don’t foul and they are bone dry. Which goes against my philosophy. Even cranked the motor without plugs and saw nothing. But we've never run it much past a breather spit. I'm running regular E-tops with tails & separate tips. (which I know is pushing the limits with 808HP) The tips have internal no-burn rubber flappers. Could the flappers be causing reversion? Like a splash back? The intakes & heads are brand new (Dart & Pro Filer) machined matched and we are using graphite gaskets which I'm told we can't do any better. Are they? I have a Gen Vi block. Where else can this be coming from? Water pressure is good, about 20-25PSI. External pick-up and sea strainers were added during the rebuild. I have no thermostat and run a cross over. I also have a restrictor plate to reduce water flow. Any thoughts out there?

NOMOGOFAST

Water pressure is high 20-35 psi. Do you have water pressure guages? At wot, you should only see at most 25 psi. I had a water pressure problem w/ my Eliminator but it was at 4500 rpm and up. No problem under 4500rpm but would have water coming out the breathers over 4500. i had to put an adjustable water pressure valve w/ a dump out the back of the boat. It's a spring loaded valve. It worked perfectly, My water pressure at wot was 40 psi, after installing the valve and adjusting it i was at 22 psi. You most likely have water seeping aroung the intake gaskets. That's where mine was coming from. I had pudding in the valley and valvetrain.


Good Luck

Blue by You

Typo on the Water pressure. 20-25. Not 35. My gauge maxes out at 35 and we're nowhere close to that. 10lbs at idle (about) 20-25ish at 4500-5000

Blue by You

Just pulled the brass plugs and they wern't as tight as they were going in. We also see that the steel plugs turn in a little farther than the brass did. So maybe this is a good sign. Hope to have new test results tonight or by morning. Spoke to CMI as well and they disagree with any reversion. Reversion would happen at idel, not 4500 and it would need to be enough to foam the pan, & we're not seeing anything on the dip stick. I do have 12 qt Stef pans.

kennyo

Intake gaskets need to be retorqued after you run it. Happened to me and happened to a buddy this weekend.

Blue by You

I'm sure they were re-tourqued but I'll triple check it. Still waiting for the water test this AM.

kennyo

Good luck.

Blue by You

Wouldn't that have shown up on the pressure tests?

Griff

Its definately not reversion. Reversion happens mainly at idle with the overlap of the cam sucking back in. At higher rpms, there is plenty of pressure to push all the water out out the exhaust.

Blue by You

PROBLEM DIVERTED!!!
Ended up being those damn brass plugs. We not only pulled them, we re-tapped them and put larger plugs in with high performance thread sealer. The holes were drilled from pro filer at a bit of an angle and it exposed the threads...were thinking this along with the expansion rate of the brass vs Alum. let the water in... I'm considering still putting in a pressure dump just to be safe. Thanks for all the advise...