Hot Section Rebuild

**sastanley** · 03-21-2011, 04:20 PM

Ed - very nice!

Although not replacing mine, I had to pull it off to get the painting done..now I am switching over to studs in the manifold .

**Al Schober** · 03-21-2011, 05:43 PM

Ed,
You must consider yourself fortunate to have the room for such a nice hot riser. Well done!

Al

**Crash** · 03-21-2011, 11:33 PM

Thank you Ed for posting your photos as I'm about to rebuild my hot section as well. Unfortunately I don't have the room you seem to have so I'm stuck with severely rusted parts and trying to wrench them with a 6 inch wrench isn't making it. So for me it's PB Blaster time! And when the rain stops I'll be back in the hole again.

Crash

**Laker** · 03-22-2011, 07:06 AM

Possible dumb question time :

How is it that your exhaust leaves the manifold on the front , or flywheel end of the engine?

**ILikeRust** · 03-22-2011, 08:00 AM

Quoth our benefactor:

"Original factory manifolds were produced in two different types: Those with exhaust openings only in the reversing gear end and those with openings on both ends. The double-ended manifolds accommodated engines with "V-drives" and other boats which had exhaust systems that exited the vessel other than through the transom."

To be found about 1/4 of the way down the page here.

**edwardc** · 03-22-2011, 08:40 AM

Originally posted by Crash View Post

Thank you Ed for posting your photos as I'm about to rebuild my hot section as well. Unfortunately I don't have the room you seem to have so I'm stuck with severely rusted parts and trying to wrench them with a 6 inch wrench isn't making it. So for me it's PB Blaster time! And when the rain stops I'll be back in the hole again.

Crash

The camera always seems to make it look roomier than it really is. The side view is taken by holding a camera at arms length through a small opening while crouched in a sail locker!

In my case, I had to remove the hose clamps from the waterlift muffler and the exhaust flange bolts (which, thankfully, were already stainless) and remove the whole hot section as a unit.

Originally posted by ILikeRust View Post

... The double-ended manifolds accommodated engines with "V-drives"..."

Bill, you are correct. I have a v-drive. The engine sits "backwards" from most installations, with the flywheel end towards the stern. The v-drive reverses the direction and rotation of the shaft, alowing the engine to be located further aft, right on top of the shaft log and under the cockpit floor. There's a picture of the engine without the v-drive installed in my Engine Install album: http://www.moyermarine.com/forums/al...&pictureid=524

**Laker** · 03-22-2011, 02:02 PM

Ah , backwards , and along with that comes an alternative oil fill installation. It all makes sense to me now. Thanks.

**Nick duBois** · 03-23-2011, 03:11 PM

Nice hot riser Ed. I wish i hard the room you have lol... I have room to get one arm and my head in through the starboard quarterberth, even less on the port side.

Nick

**domenic** · 03-23-2011, 03:44 PM

Good job mister Mister plummer.Your V-drive exit had me wondering.

**Crash** · 04-19-2011, 07:08 PM

Just came back from the boat where I installed a rebuilt hot section. This is not the final "in-place" section as I'll go back to install thread sealant before tighten every thing. I had to fuss a little with all the fittings to get them lined up correctly but it turned to looking like the pictures I attached to this post. I started the engine up (first time in a month) and she kicked over the first time...darn near sounded like a race car! After an acid flush and the hot section rebuild it seems there's more cooling water discharging out the stern so I'm actually real happy.

Conceptually I think it works??? Comments??

Thanks,
Crash

Sorry for the huge picture files..not sure how to scale em down..

Attached Files

Mo · 04-19-2011, 08:14 PM

Nice Job.

Nice job Edward. Hope it all goes well for you....the engine rebuild as well.

**sastanley** · 04-19-2011, 09:49 PM

Crash, if it was me, I would get the injection mixer as low as possible. From what I've read around here, you want a minimum of 6" of hose between the mixer & the muffler. I even have a plastic Vetus muffler and I have about 4" and have never had a heat/melting problem. The idea is to give more space in a hard starting condition for the water (being injected while the starter is spinning) to not fill up the hot section and dump into #4 cylinder. So, maybe add a piece of black pipe between the mixer & 90 degree elbow and cut the hose at 6" and see how it looks.

I also notice you have a bend in the hose which may make my theory above difficult...why not make another 90 degree with hard pipe and then have the mixer between that and then a few inches of hose between the mixer and the metal muffler.???

My $0.02

**Crash** · 04-19-2011, 10:43 PM

Thank you Shawn! I actually had the mixer piece closer to the muffler but working with that wire reinforced exhaust hose is a #*@%#! And all the while I'm in a fetal position I just said #$@* it and left it this way just to see what y'all thought. I'll be back down to the boat tomorrow and try it out your suggestion and see how it'll work. I'll be armed with heat gun this time.

The bend in the hose is actually a nice transition into the muffler all because the hose is a 'pain' to work with. With the thought of getting the mixer closer to the muffler I'll see how everything works and keep you all posted.

Thanks!
Crash

**jpian0923** · 04-20-2011, 02:15 AM

Different opinion:
I think your water injection point into the hot section is fine where it is. If, and only if, the integrity of your entire exhaust system is intact/adequate.
What i mean is, whether in a hard starting situation, normal starting situation or even when hand cranking, the relationship of water being pumped through the system to the amount of exhaust/air (engine as an air pump, which it is) being pumped through the engine, remains the same at all RPM's.
So, If you have a good manifold gasket, the manifold is torqued properly, the exhaust flange and gasket are air tight and all connections up to and beyond the water injection point are tight, I can't see how water can back up into cylinder #4.

I've seen many threads that suggest closing the thruhull until the engine is started, to prevent water back up, and I don't see why.
Am I missing something here?

I had to get that off my chest...been bugging me for a while now.
What am I missing?