Exhaust Hose

[Mike_Lenz]

Good afternoon all, I’m looking for some information regarding the size of the exhaust hose on my engines. Previously the B35 was equipped with 454’s that had 3â€� wet exhaust hose. The engines were replaces with 8.1 Crusaders with 4â€� exhaust manifolds; a reducer was installed so the original 3â€� hose could be used. Does anyone have any experience with the 3â€� vs. the 4â€� hose, does it have any effect on the engines either short or long term. Thanks, Mike….

[JohnD]

I'm not sure about the 8.1's but in general it would possibly increase the back pressure. check out www.crusaderengines.com and shoot them an e-mail. You can also find the install manual which may cover the issue. br, John D "Lady D" Bertram 35 Pasadena MD

[franklyprice]

Mike, I certainly would be concerned about how much backpressure you have with those 3" exhausts. There will be a spec. for it from crusader . As long as it's within spec. I wouldn't worry but you should check it.

[Mike_Lenz]

Thanks Guy’s After reading the service manual it does call for 4â€� exhaust hose. Thanks again, Mike….

[captgene]

I don't know what year they changed. My boat is a 1989. I have 4 inch at the engines, and going to 5 inch at the elbow going into the muffler. When I talked to Crusader about the 8.1s, this was recommended for them too. I'm surprised they reduced 4 to 3. Gene Dugan Boca Raton, Fl. "Nauti Marie" 1989 33 FBC

[alano]

Mike, while the deck is off - I did with the deck on and while doable it's no fun, replace the exhaust with 4"->5" Y into a 5" muffler and 5" to the transom, the 8.1s need to breathe. The diverters on the transom will fit over the Buck Alquoquin bronze 5" thru hull, get the angled one - the straight won't work. It's not a good thing to reduce exhaust hose although it was done on 454s as well. Alan.

[Mike_Lenz]

Thanks Alan, I’m going to take your advice and replace the exhaust hose when the deck is out. Thanks again for you help, Mike……