230lx434

Motor is off dyno officially. 618HP @ 6200. motor has a pretty big cam for a boat so im extending my risers as far to tip as i can without burning anything up. Can run dry all the way to the tip and let water exit along with exhaust at tip but i am running an external flapper ONLY and dont want to melt external flapper. With that being said how far away can i have the internal exhaust pipe come out to before it needs to stop behind flapper without melting it? Water will exit jacketed pipe (outer) about 4" behind the exhaust (hot pipe/ inner). How close can i get the inner exhaust to the tip safely? obviously the closer the better with this cam. Only reason for external flapper would be water intrusion from exterior of boat since tails are under swim platform but a few inches above water line.

Ryan00TJ

iTrader: (8)

With the water mixing at or inside the tip you should not have to worry. Now if you ran them dry that's another story. My current setup is roughly 6" from the external flappers. Previous setup was 3". No problems.

230lx434

Going to make much difference on possible reversion if it mixes 4" from tip vs dry? I know dry is a guarantee but I'd rather not drills holes to dump the water if i dont have to.