[justrollin]

Just noticed some rust between my exhaust manifold and riser on my fresh water cooled  454 crusaders going to change risers and gaskets if its leaking out it might be ready to start leaking in we don't want that not to say it can rust the surface of the manifold that will make for a bad seal. Any other thoughts on this engines run cool 180 but I don't know how old they are so best to change them.

[RMS]

In my experience, Crusader risers have both a part number and date code cast into the riser.  You should be able to determine the age of the riser in that manner.  Bob

[justrollin]

They have been changed out with sierra on there now so no way to know how long they have been on there

[stugiv]

Saltwater? From what I've read, it's a general rule to change raw water cooled risers/elbows every 5 years or so. When I changed mine, I wrote the year on them with a sharpie for my reference or any future owner.

You could use an infrared thermometer to check the temps of the risers/elbows. According to my surveyor, if they're much above 160 degrees, they're probably getting clogged with scale. Prior to changing mine, the highest temp I recorded was 185 while 135-145 seemed to be normal operating temps for the risers/elbows.

[Captain_Lee]

Saltwater? From what I've read, it's a general rule to change raw water cooled risers/elbows every 5 years or so. When I changed mine, I wrote the year on them with a sharpie for my reference or any future owner.

You could use an infrared thermometer to check the temps of the risers/elbows. According to my surveyor, if they're much above 160 degrees, they're probably getting clogged with scale. Prior to changing mine, the highest temp I recorded was 185 while 135-145 seemed to be normal operating temps for the risers/elbows.

If it is in warm saltwater, for example, South Florida... locals typically change them out every 2 to 3 years.  It's pretty cheap insurance against the cost of not doing them!