Exhaust Elbow Question 7.4 Blue Water I/B

[sandkicker]

Engine S/N 0F229xxx

Friend's boat.... been fixing the obvious bad stuff for him as "his plate is full" and just got to the elbows...Engine has no symptoms of elbow problems,just looking at possible PM.
Apparently elbows are NLA and also apparently there are 2 versions listed , a 816900A5 and an
A7. From what I see, the A7 is spec'd as stainless but can't find out if the A5 was as well (should be but???) . If the boat wasn't a hours drive away, I'd just take a file to the elbow and check the material... Two questions.... Any way to tell if A5 or A7 from the S/N? And most importantly, these look like the original elbows... If stainless, what is the life expectancy??? Engine has heat exchanger and is a full system.

 

[Dieter]

Engine S/N 0F229xxx

Friend's boat.... been fixing the obvious bad stuff for him as "his plate is full" and just got to the elbows...Engine has no symptoms of elbow problems,just looking at possible PM.
Apparently elbows are NLA and also apparently there are 2 versions listed , a 816900A5 and an
A7. From what I see, the A7 is spec'd as stainless but can't find out if the A5 was as well (should be but???) . If the boat wasn't a hours drive away, I'd just take a file to the elbow and check the material... Two questions.... Any way to tell if A5 or A7 from the S/N? And most importantly, these look like the original elbows... If stainless, what is the life expectancy??? Engine has heat exchanger and is a full system.

cant help you with part numbers but i believe that generally the stainless elbows essentially last forever and is why people use them with full closed cooling to never have to change that stuff again

check this link out there are notes on the elbow drawings drawing 1&2 with different boss locations. I think one is for risers maybe one with out ?

http://www.marineengine.com/parts/m...u-0k999999/exhaust-manifold-and-exhaust-elbow

 

[kghost]

cant help you with part numbers but i believe that generally the stainless elbows essentially last forever and is why people use them with full closed cooling to never have to change that stuff again

check this link out there are notes on the elbow drawings drawing 1&2 with different boss locations. I think one is for risers maybe one with out ?

http://www.marineengine.com/parts/m...u-0k999999/exhaust-manifold-and-exhaust-elbow

What a bunch of bone heads

Drawing 1 and 2

A for closed
B for raw

One would think it would be
1 for closed
2 for raw

 

[sandkicker]

Thanks for the info guys !!! Would be nice if there was a SS version of the dry joints for my 5.7!

 

[Dieter]

What a bunch of bone heads

Drawing 1 and 2

A for closed
B for raw

One would think it would be
1 for closed
2 for raw

View attachment 27165

yeah the A and B refers to the two small drawings above dray wings 1 and 2 show and closed gasket in one and riser in the other. i think the elbows they must have changed the items mounted on them and thus the boss locations .

 

[Dieter]

Thanks for the info guys !!! Would be nice if there was a SS version of the dry joints for my 5.7!

I havent seen the ss ones for anything remotely new year wise. Probably not to many bucked up for the ss ones.

All this makes me appreciate fresh water as unless you dont drain the manifolds they last the life of the boat generally...

 

[sandkicker]

yeah the A and B refers to the two small drawings above dray wings 1 and 2 show and closed gasket in one and riser in the other. i think the elbows they must have changed the items mounted on them and thus the boss locations .

Thunderbolt ignition electronics mount to the elbows....

 

[makomark]

Bob:

There was a service bulletin out for many of your questions back when Mercruiser decided to quit using the SS elbows.

I've had two pairs on since the mid-90's and haven't had any issues.

FWIW, a magnet is a better (NDI) discriminator....