Hi all,have just rebuilt a 502 mag/mpi and put it back in the boat.It had a set ot hi tech stainless headers which I extended the water jacket to make dry.water now exits separate from exhaust gas.my problem is that the exhaust tips on outside of transom are getting too hot,i can touch the manifolds,plenty of water coming out,even hold my hand in the exhaust gas at low revs and not burn.what is going on?expansion?is there a solution?

If the exhaust pipe touches the transom it HAS to be water jacketed or have the water induced before the transom to cool the pipe. If you don't do this you just might burn up the boat.

Where does the water dump??? You need to dump some water in the tips if they are ot 100% jacketed through the transom.

now dumping a little water into tips,big reduction in tip temp.Thanks Fellas