I am in the process of repowering my Baja 250 ES. I am going from a 468 bbc to a 572 bb. I currently have Eddie Marine Thunder Exhaust. I was told today that those exhaust would not work with that many cubic inches due to water reversion. Thanks in advance for any input. Sidney

First thing I would say is We ran Eddie Marines on a 540 I built with 758 dynoed HP and never had an issue. The reversion issue is not so much the exhaust manifold, but the cam that you might be running. If reversion is a concern...get the long risers and you should be fine. I ran the short risers like the ones that you would use to hook up the silent choice or Corsa thingy.

i explained to him the engine did not have a big camshaft. He said I would still have problems. How long did you run them?Never any reversion?

SidneyW , listen to what Eddie says. We have a ZZ 572 that we put the EMI Thunder exhaust system on. Believe it or not we didn't loose much power going from the dry Stellings ,but we started having reversion at idle.
We asked Eddie to make taller risers for us , and that cured the problem!

Stellings were way too loud for my friend's marina ,and also kept cracking at the exhaust flange on the inside tube ,so had to go.
Stelling setup


Eddie setup



Interir db testing without the doghouse
http://www.youtube.com/watch?v=6L-st0izosU

Still has a nice runble with the mufflers

http://www.youtube.com/watch?v=QtMEm...eature=related

You will NOT have any reversion problems running the Eddie marine's with the long risers...

http://www.eddiemarine.com/store/car...l&p=13075&c=63

The link is the 540 motor that is making 758 HP and it is the same motor that had the Eddie marine exhaust manifolds on with the SHORT risers running a Crane #139741 hydraulic roller cam for alittle over 11 months. The motor has CMI headers on it now...$4500.00...what a waste of money for the CMI's. Only got a 2 mph increase by going to teh CMI headers. Wont EVER make that screwup again.

http://www.youtube.com/watch?v=a7q182DGDm0

The 572 in the pics...is that a crate motor from Jegs or Summit Racing...looks exactly like what they offer, because if it is, then its a car motor and no wonder there is reversion. The cam causes reversion...NOT the size of the motor.

OK, Do you have the long stainless risers? Short risers will not work. What cam are you getting? Get your cam from Bob RMbuilder, tell him what you have and you will not have any problems.

Quote:

Originally Posted by PSlonaker

[The 572 in the pics...is that a crate motor from Jegs or Summit Racing...looks exactly like what they offer, because if it is, then its a car motor and no wonder there is reversion. The cam causes reversion...NOT the size of the motor.

The cam was changed when the dry exhaust was removed!

Thanks so much for your info. I will check into higher risers. This thing is killing me financially!I may just go back with my 468 and sell the 572. That is a nice setup you have!What kind of boat is that?

Homebuilt by my friend. 34' , best speed was 65 with the Stellings, 63 with the reduced cam and EMI Thunder exhaust.



Next to my Navi

Helluva setup! Looks like a 63 split window Vette!