5.7 Riser - Clean and reuse or replace?

[Glevans1]

Hi all. I guess a lot of you have asked the same. Reuse or replace?

Here’s a couple of pics of the riser on my 5.7 GSi after I used a drill with a length of 1/4 cable to try to clean up the water passages. Not a lot of rust came out but I noticed there was a thin middle wall (first pic) on the narrow side passages which my cleaning efforts have partially removed. Is this separation wall needed?
Parts are OEM Volvo Penta, 6 years old with about 850 hours. Used 85% in fresh (brackish water) 15% salt. Freshwater enclosed cooling system.

Thanks for any advice.
2001 Skagit Orca
C-Tow Steveston Vessel Assist

 

[jerryjerry05]

Check the outlet for clogs and run a piece of wire
through that.

 

[Bondo]

Ayuh,...... Failures occur when the flatness of the inner wall, 'tween the exhaust, 'n water jacket gets too thin to support the gasket,.....
It looks Good, in the pictures,....

 

[BRICH1260]

Looks good to me. I`d run it another year or two.

 

[Lou C]

From what I can see in the pix they look good, but after you clean off all the old gasket material you want to see nice non-pitted cast iron on the gasket sealing surfaces so that the gasket will seal well against both the manifold and elbow (what you are calling a riser is actually an elbow). Risers are extensions to increase the height of the elbow.

 

[Glevans1]

Thanks for your responses. I believe I’ll reuse these manifolds and elbows with new gaskets and plan for replacement when I do my Spring maintenance next year.

 

[Lou C]

Another good test after cleaning the old gasket material off is to lay a straight edge across it and try to slide feeler gauges under the straight edge. If a .001” won’t fit that’s really good. I tried this on a new set of Barr exhaust I installed 3 years ago and that’s what I found, less than .001” and no leaks.

 

[Glevans1]

From what I can see in the pix they look good, but after you clean off all the old gasket material you want to see nice non-pitted cast iron on the gasket sealing surfaces so that the gasket will seal well against both the manifold and elbow (what you are calling a riser is actually an elbow). Risers are extensions to increase the height of the elbow.

Thanks for the clarification, Lou C.

 

[bruceb58]

Risers look fine to me.