Removing exhaust elbows.

[findinghomer]

Hi guys, I recently removed my engine. To do so, I loosened my exhaust elbows from the 3-inch Riser block ( not from the manifold) to lift up an inch or so so I can get the rubber hoses off. I could not completely remove the elbow because of my engine bay clearance. I removed it enough to give me some room to wiggle the rubber hoses off. I got everything back together, and now I have one side running hotter than the other ( engine is not overheating, and the drive is a brand new assembly so the impeller is good) So I want to take the elbow off and inspect everything, like I should have done with the engine out but I didn't know any better. But after doing a lot of reading it sounds like that's what I need to do. Now that I understand exhaust risers and manifold much more, now I'm worried that when I removed that elbow from the Riser block, I may have damaged the gasket. If I did so with that allow water to get into my engine? Any rate I need to remove the elbow. But just like before I cannot do that because of my engine bay clearance. I would have to remove all for studs and remove the elbow and 3 inch Riser block from the manifold in order to do so. How do I go about this? My setup, is an exhaust elbow and riser block being held together with four lag studs and then a nut on top. Any input or tips are welcome, I appreciate it thank you

 

[Bt Doctur]

can you modify the engine bay opening by cutting?

 

[Bondo]

now I'm worried that when I removed that elbow from the Riser block, I may have damaged the gasket.

Ayuh,.... If ya broke the seal of the gasket, 'n didn't clean the surfaces, 'n replace the gasket, Ya, yer gonna have problems,.....

Can ya remove the complete manifold/ riser/ elbow as an assembly,..??

Worse case, pull the motor again,....

 

[findinghomer]

Ayuh,.... If ya broke the seal of the gasket, 'n didn't clean the surfaces, 'n replace the gasket, Ya, yer gonna have problems,.....

Can ya remove the complete manifold/ riser/ elbow as an assembly,..??

Worse case, pull the motor again,....

Maybe, that would be pretty heavy though wouldn't it? What if I remove the riser and elbow as an assembly by removing the studs from the manifold? Is that possible?

 

[findinghomer]

can you modify the engine bay opening by cutting?

Idk, I thought about that, but I'm hoping to avoid it . at the same time I want to avoid pulling the engine again. I will check it to see how minimal The Cutting would be. Seems like a bad design to have to pull the motor to remove exhaust elbows

 

[Bt Doctur]

A 28 Wellcraft Coastal I maintain you have to remove the riser to remove the motor. All they had to do was enlarge the hatch opening 2 inches to avoid that.

 

[findinghomer]

A 28 Wellcraft Coastal I maintain you have to remove the riser to remove the motor. All they had to do was enlarge the hatch opening 2 inches to avoid that.

What do you think I should do from this point to check for water intrusion? Pull plugs, check dipstick?. I don't have any symptoms besides the hot starboard side elbow, I'm just worried after reading so much about these things , since I pulled that elbow up off of the riser. I know when I had the motor out, there was no water in the oil, or any of the cylinders. So if something is wrong it what have been when I removed that elbow. Also keep in mind I removed the elbow from the Riser, not from the riser to the manifold.

 

[Strecker25]

Just curious... what motor is it? I have twin 350 alphas and after replacing riser/mani's last year the stbd side runs a bit hotter after the t-stat opens. I went a bit crazy thinking something was wrong but turns out that is "by design". I called Merc and after talking to a tech and examining the cooling system diagrams the water that goes to the stbd side is the water that has already ran through the block, so it's about 8-12* hotter at the elbow.

I still think you should pull them apart especially if you didn't replace the gasket but just wanted to point that out.

 

[findinghomer]

Just curious... what motor is it? I have twin 350 alphas and after replacing riser/mani's last year the stbd side runs a bit hotter after the t-stat opens. I went a bit crazy thinking something was wrong but turns out that is "by design". I called Merc and after talking to a tech and examining the cooling system diagrams the water that goes to the stbd side is the water that has already ran through the block, so it's about 8-12* hotter at the elbow.

I still think you should pull them apart especially if you didn't replace the gasket but just wanted to point that out.

Thanks for the reply, it is a 1997 5.7 liter 350. I don't remember them getting this hot. I can touch it, but only for a few seconds before it's too hot. And the exhaust that is exiting on the starboard side is very hot compared to the port side

 

[Bondo]

I don't remember them getting this hot. I can touch it, but only for a few seconds before it's too hot. And the exhaust that is exiting on the starboard side is very hot compared to the port side

Maybe, that would be pretty heavy though wouldn't it? What if I remove the riser and elbow as an assembly by removing the studs from the manifold? Is that possible?

Ayuh,.... Boat motors never run even temps on both sides of the exhaust,......

Felt heat, is a poor thermometer,.... Stick yer hand in 120? water, 'n tell me how hot it "Feels",.....

The manifolds might be 40 lbs, not bad,....
If ya can get the studs out, it might be possibly,....
Might be hard to hold the gasket in place, slidin' it all together,.... donno,....

The fact that ya broke it loose, means it's a fact, it's Gotta happen,....
Yer riskin' hydro-lock til ya do,.....

 

[bruceb58]

Get an IR thermometer and measure the temps. I used to write mine down the start of every year but I stopped doing that. Not a bad idea to do so you have a baseline temp.

 

[findinghomer]

Ayuh,.... Boat motors never run even temps on both sides of the exhaust,......

Felt heat, is a poor thermometer,.... Stick yer hand in 120? water, 'n tell me how hot it "Feels",.....

The manifolds might be 40 lbs, not bad,....
If ya can get the studs out, it might be possibly,....
Might be hard to hold the gasket in place, slidin' it all together,.... donno,....

The fact that ya broke it loose, means it's a fact, it's Gotta happen,....
Yer riskin' hydro-lock til ya do,.....

Lol. Thanks Bondo. I actually did get the studs out, fairly easy. Got one Riser off, and noticed a pool of liquid in the manifolds about the size of a half dollar. I dipped a paper towel in there to soak it up, so I could smell it. it was water. Can you guys advise me what I should do. Pull the plus, change all gaskets, including the manifold?

 

[findinghomer]

Okay guys, I'm getting ready to put everything back together. I just want to make sure that I have these gaskets in the right position. When I took it apart the gasket that goes underneath the exhaust elbow , to the top of the 3-inch Riser block was the restricted flow gasket, then the one that went against the manifold to the bottom of the riser was open flow. However when I look at the schematic for the parts, the restricted flow is on the manifold and the OpenFlow is on the top Riser block. Does it matter which way they go?