Logo
FULL SITE MENU

3" to 4" Elbows

M

Mike29

Contributing Member
I want to replace my elbows on my 454 crusaders and have a question. I'm doing it more as preventive than neccessary but boats been in water 2.5 years.Going to haulout this Wendsday. I was told by a mechanic if I'm replacing my elbows I should go with the 4" outlet rather than the 3". I Know about less backpressure but my log style manifolds only have a 3" outlet to the elbows. Just want some pro opinions here as to do the 4" I need to change out 2 fiberglass 45's and 2 of the 3" to 5" Y adapter to my mufflers....will it be worth it? Has anyone here done this?
 
Just want some pro opinions here as to do the 4" I need to change out 2 fiberglass 45's and 2 of the 3" to 5" Y adapter to my mufflers....will it be worth it?
Click to expand...

Nope,....
 
"..worth it?" - depends upon how much use the boat gets....unless it is a lot, then not likely to be cost effective.

"...done it?" - yes, but also changed the "log" style out for a "center riser" style, and everything else to the transom. Was 3" to 4" (ID) and became 4" to 5" - the combination mad a minor improvement in efficiency and a huge change in throttle response.
 
My intent is to just change the elbows. If I open her up and need to change the manifolds...I'll go 4" then. Thanks everyone for the input. Everything from inlet to mufflers to transom is 5"..
 
Keep in mind that hot exhaust gas collapses to about 1,000 times in volume after the water mixes with it. Automotive applications don't have that advantage.

lJeff
 
Back
Top