Flapper & Scupper?

[laserbrn]

I am finally getting the time to get my Skipjack together! I am replacing all of the exhaust components and I've already replaced the manifolds and risers. The previous owner set the boat up to have the exhaust exit under the swim step.

The way he did this was using "S" pipes from the risers that lower the exhaust point and put it under the water. He installed what I would call "scuppers" inside the old "S" pipe. Presumably this was a precaution to ensure that under deceleration water wouldn't be forced up the S pipe and potentially into the engine. There are flaps on the outside of the through-hulls for the same purpose.

In order to install these scuppers, I'd have to find them, then drill the S pipes and install them. Presumably the clamp will be right over it and the hose will cover the hole so it should be sealed. I've never seen a setup with both flappers and scuppers so I'm curious if you all think it's necessary to reinstall in this fashion?

Thanks in advance. I've attached pics of the new pipe and the old pipe.

 

[Bondo]

Re: Flapper & Scupper?

I am finally getting the time to get my Skipjack together! I am replacing all of the exhaust components and I've already replaced the manifolds and risers. The previous owner set the boat up to have the exhaust exit under the swim step.

The way he did this was using "S" pipes from the risers that lower the exhaust point and put it under the water. He installed what I would call "scuppers" inside the old "S" pipe. Presumably this was a precaution to ensure that under deceleration water wouldn't be forced up the S pipe and potentially into the engine. There are flaps on the outside of the through-hulls for the same purpose.

In order to install these scuppers, I'd have to find them, then drill the S pipes and install them. Presumably the clamp will be right over it and the hose will cover the hole so it should be sealed. I've never seen a setup with both flappers and scuppers so I'm curious if you all think it's necessary to reinstall in this fashion?

Thanks in advance. I've attached pics of the new pipe and the old pipe.

Ayuh,.... What are We workin' on,..?? What motor/ drive,..?? Gonna need Alot more Pictures....
Maybe an over-all view of the area....

What I see is a cut-up elbow, 'n what appears to be a piece of y-pipe with a shutter.... possibly Merc pieces...

 

[laserbrn]

Re: Flapper & Scupper?

The motor is a 7.4l chevy big block. I guess since I know what I'm looking at the pictures seem to tell the story. I can try to take some pictures tonight of the setup. It's an under the swim step exhaust that comes off the risers/elbows...and runs through the s-pipe and out the back through the exhaust tip through-hulls. It doesn't have a Y-pipe anymore as I'm not running exhaust through the drive.

 

[Bondo]

Re: Flapper & Scupper?

The motor is a 7.4l chevy big block. I guess since I know what I'm looking at the pictures seem to tell the story. I can try to take some pictures tonight of the setup. It's an under the swim step exhaust that comes off the risers/elbows...and runs through the s-pipe and out the back through the exhaust tip through-hulls. It doesn't have a Y-pipe anymore as I'm not running exhaust through the drive.

Ayuh,... Ok, so ya have the risers on top of the manifolds, dumpin' into the cut off elbows in yer picture,..??

Which then dump into these "S" pipes,..?? which have the "Shutter assembly", at that point,..??

'n then there's flappers at the outboard end of the "S" pipes, outside the transom,..??

If I'm remotely close,....
Post more pictures of this "Shutter assembly", 'n maybe somebody can figure out What it is, or how to make something work in there....
pictures of where it's supposed to live too,... "In Position" so to speak...

What are the "S" pipes made of,..?? SSteel,..?? Aluminum,..??

 

[laserbrn]

Re: Flapper & Scupper?

The pipe is made of aluminum. You seem to be imagining exactly what I was attempting to describe. The "scupper or shutter" was inside the pipe and there were flaps located outside the transom as well. I'm planning on running new flaps outside the transom and I'm thinking that this will be enough.

I haven't measured the height from the waterline to the risers, but they are up there pretty high. I definitely wouldn't want 4 fat beer drinking buddies at the stern of the boat in a following sea, but that's inherently true about this type of setup. I don't really want to pull the motor to install a factory Y pipe and I don't want to plug the holes where the through hull tips are. I assume he placed them below the swim step and below the waterline to allow the boat to run quieter in the marina.

The pictures here show where the exhaust tip is outside of the transom (which I know needs paint badly, but running first, then pretty). And interior first, then exterior for this project. The second photo shows the black "S" pipe that I've attached. I hadn't installed the lower exhaust hose when I took the picture.