Exhaust Bellows do they matter?

D

DavePant

Member
Aug 5, 2019
39
Boat Info
1989 270 Amberjack
Engines
5.7L Twin
I have a 1989 Amberjack with twin 5.7 I/Os in it and they both have Alpha one Gen 1s on them. While I had the lower unit part I noticed one drive has ribbed bellows and it is clamped from the Housing to the gimble ring on both sides. This seems obvious to me that is like that so it can stay connected and move back and forth. However on the other drive my exhaust bellow is just a oval piece of rubber clamped only on the housing. It looks like it could be clamped to the gimble ring but if it was then it could not move. I did see some exhaust bellows for sale and some do not have ribs in them so it can do the accordion thing. Here is a pic.
 

Attachments

  • 20190901_144140.jpg
    20190901_144140.jpg
    160.2 KB · Views: 833
The smooth non clamped exhaust tube is used on the 350/B3.

The only issue is increased exhaust noise.

I’m not sure if it’s a heat issue or a back pressure issue, but no bellows for these applications.

I assume the alpha applications are similar.
 
The SLEEVE is totally acceptable IF you don't mind the extra noise. I had a 98 Baja 212 Islander with 7.4 bravo 1 that came that way from factory though it did have Corsa thru-Hull exhaust, the sleeve is much easier to install if you don't have the bellow tool
 
Technically you do not even need an exhaust bellows so either one is fine.
 
I went with the exhaust tube when I did the bellows on my alpha I. It is a little louder, but much easier to install. It’s almost a personal preference - if more engine noise is going to bother you then do the full bellows. Functionally they perform the same.
 
While some may choose which to install (bellows or tube) beware that if you have a 300 hp or higher application, the tube is the proper item to use.
 
You must log in or register to reply here.

Forum statistics

Threads
113,170
Messages
1,427,762
Members
61,080
Latest member
Jfeg
Back
Top