Reversion problems with 47's with 525EFI's...
 

I am being plagued by reversion issues on my back two motors. I had discovered reversion problems last year and I had CMI make me custom full length dry tails (dry to 1" of the end) and I removed the silent choice. Thought that would solve my problem for sure. Had to do some other work on the motors a few weeks ago so I removed the headers and lo and behold, I am still seeing signs of reversion and had one stuck valve. Now, I also put on those sexy stainless steel external flappers and the only thing I can think of is that the flappers are too heavy and they are trapping too much water in the pipe and its creeping back up.. Here are my questions:

1) Any of you 47/525 owners experience reversion and what have you done to solve it?

2) Anyone run without ANY external flappers at all? My concern is backwash...

Any other ideas / suggestions welcome...

Not again...:((( sorry to hear about it...

Dam - sorry to hear this.

I believe these would solve your reversion issues.

http://www.gibsonperformance.com/marine-turndown.php

Dean

I doubt it would... but I'm no expert...

Are you sure its reversion and not header issue ?

Thanks Dean, but I think those would actually make it worse. The exhaust water exits an inch from the tip of the tailpipe. IMO that water would splash backwards hitting the hard surface of that turndown.

I am no expert either but that is what they told me at Gibson, and they are in that field.

Dean

Absolutely positive. I have pressure tested all six headers extensively. I have water intrusion and salt crystals in cylinders 3,4,7 and 8 on both motors. Those cylinders correspond to the two bottom pipes of the collectors on both sides of the motor. Even if I hadn't pressure tested, which I have, the odds of leaks in the exact same four primaries on both engines is low.

Try those salisbury flappers that clamp on the OD od the pipe. http://www.cpperformance.com/p-13183...l-flapper.aspx