What engine would you put in your boat?

[Michigan boarder]

Hey Woodski, I just logged on.

I tried getting the hoses in but they will not work straight to the tips, 1) the engine mounts are in the way and 2) even if I got past the mounts or built something to keep the hoses from rubbing on them the angle is too severe into the bilge, so I'd at least need 45's. So I'm back to working with what I have - and going for it with the silencer.

Noise out the back is not good. When I leave the marina I need to get up on plane pretty quickly straight out to get over the shallow section (3 to 4 feet deep), so I'll be shooting that noise right back at the marina. Which is also the dude's house. I think I'll become unpopular pretty quickly, I am really hoping to have a 7am crew every Saturday. So I'm going to try the fiberglass stuff and see how that goes.

[Michigan boarder]

Update: I'm not very good at fiberglass work. But I think I have it figured out now. 3rd time should be the one.

I really need to tear down that garage and build a new one, doing this stuff off-site is a complete PITA.

[Michigan boarder]

I finished up the intake, moving them to 3.5". Got them in there solid. Then I started in on the outputs, cutting the holes larger to fit the 3.5" sleeves inside of them. During that rattling around, part of the guts came loose inside the silencer. So I figured screw it, out come the guts. So the engine is definitely going to breathe a lot better. I am still using the silencer, the rule is to eliminate the "line of sight" of the exhaust flow, correct? So the exhaust will come into the muffler thru a 3.5" opening, then swirl thru the silencer and go out thru another 3.5" opening. Any suggestions beyond that as far as baffles?

Here is a picture of the old baffles that have been removed. The exhaust would come in thru openings on the outside ends of the muffler, then have to pass thru the shorter end of the baffles, make a U turn and out thru the longer ends which would connect to a 90 degree bend. All of that output was less than 3".

[Michigan boarder]

The baffles were epoxied into position.

[Michigan boarder]

And they were small in diameter:

[Michigan boarder]

Here is the new in and out. The outlets are not glassed in yet, I just put them in there while positioning the silencer in the boat, figuring out the angles.

So what do you guys think? Glass those in and go with it as is? The 3.5" sleeves that I will install will poke into the silencer by about 1.5".

[Michigan boarder]

Here it is fitted into position, dusty from grinding down the burrs. It will also be painted. I plan on getting those outputs angled a bit more so that at the floor I will have a 45 degree elbow to the long exhaust hoses (again all 3.5").

[Michigan boarder]

Top view:

[ahopkins22LSV]

Looking good man! Looks like you are close, which is good because this weekend looks really nice.

[jk13]

Don't worry about the internal baffles. Will be fine as is and not much louder, if any, and should sound awesome. Definitely want the flow either way.

Looking good! Nice glass work on the intake side too. You must be getting pretty excited seeing the light at the end of the tunnel.

[Michigan boarder]

Looking good man! Looks like you are close, which is good because this weekend looks really nice.

I know!! The marina just opened for business yesterday. I'm stopping by and paying up my rental tonight. Coaching soccer tonight, then helping run a track meet tomorrow, then soccer team pics and coaching Wed, then helping a buddy open his cabin on Thurs (and a guy's night out after that). Got Friday off to work on the boat lift, gotta finish moving the wheel to the other side, and installing the cable. Hopefully installing it Friday night. Then soccer Saturday and off to the lake house to sign up a new realtor. Then her parents place on Sunday. Next chance for boat work is a week from yesterday.

Don't worry about the internal baffles. Will be fine as is and not much louder, if any, and should sound awesome. Definitely want the flow either way.

Looking good! Nice glass work on the intake side too. You must be getting pretty excited seeing the light at the end of the tunnel.

I'm actually glad the baffles came loose. I was hoping to keep it quiet, but then asking myself "why did you spend $900 on manifolds only to dumn it down with these baffles??" I think this is going to be a great set up. And yes - getting close!!

[MalibuNation]

Love to hear it ... let me know when you go for your first ride ... you're about .5 hours to the north of my work.

[Woodski]

@MB: Yes noise does travel in a line of site, although adding turns and obstructions does tend to quiet things down. Water mixing with the exhaust is also a noise suppressor. You should be fine with that setup you might look over the configuration and kind of see if the original path was more of a reversion stopper to keep water from going back up the inlet side.

I noticed your bilge fan is mounted up on the bellhousing, you want to pull the air from down low in the bilge to exhaust out the vent as that is where the vapors will collect (they tend to be heavier than air). You can simply run a hose down to near the starter or mount the fan down low and simply run the hose along the stringer to the back. The fan will actually fit right in the opening under the engine mount.

Good luck getting the vessel in the water and certainly enjoy your initial water test...

[Michigan boarder]

@MB: Yes noise does travel in a line of site, although adding turns and obstructions does tend to quiet things down. Water mixing with the exhaust is also a noise suppressor. You should be fine with that setup you might look over the configuration and kind of see if the original path was more of a reversion stopper to keep water from going back up the inlet side.

I noticed your bilge fan is mounted up on the bellhousing, you want to pull the air from down low in the bilge to exhaust out the vent as that is where the vapors will collect (they tend to be heavier than air). You can simply run a hose down to near the starter or mount the fan down low and simply run the hose along the stringer to the back. The fan will actually fit right in the opening under the engine mount.

Good luck getting the vessel in the water and certainly enjoy your initial water test...

Got that covered on the fan, I haven't installed the vent hoses yet as they would be in the way while I'm messing around with the exhaust. I replaced the hoses like 3 years ago, and have them on the shelf now waiting for me to finish the other work. They will be installed like you described with the one going low on the port side and the other going out to the transom vent.

You have me worried about the water reversion. It's impossible to tell if that was designed for that or for noise reduction. I feel like I should fab some flappers up, like we were discussing a while back. But those STE's should also keep that from happening, right?

[Michigan boarder]

Here it is fitted into position, dusty from grinding down the burrs. It will also be painted. I plan on getting those outputs angled a bit more so that at the floor I will have a 45 degree elbow to the long exhaust hoses (again all 3.5").

I actually think I'm OK. If reversion occurred, it would flow up the tubes and into the silencer. Those tubes into the silencer are not in line with the tubes to the manifolds, so the water would have to fill the silencer completely to travel up the manifolds. To further prevent an errant splash up or quick introduction of water, I can notch the inside edge of the new sleeves that I am going to glass in so that they are lower towards the inside portion of the silencer. That is, any reversion would be directed into the center of the tube and not have a chance to go to the outer portion of the tube, where it could travel up to the manifolds.

Edited April 28, 2015 by Michigan boarder

[ahopkins22LSV]

Wouldn't water traveling "up" the exhaust be fighting the air pressure in the exhaust system? Even with the engine off, it should be a sealed system right?

[Michigan boarder]

Wouldn't water traveling "up" the exhaust be fighting the air pressure in the exhaust system? Even with the engine off, it should be a sealed system right?

I don't think so. If the engine is shut off, the valves are all in varying degrees of open or shut. Plenty of opportunities for water to push the air out.

[ahopkins22LSV]

I don't think so. If the engine is shut off, the valves are all in varying degrees of open or shut. Plenty of opportunities for water to push the air out.

Yeah true. Just a though from a non-mechanic!

[Michigan boarder]

Got a couple of PVC elbows last night from Menards, schedule 30. $1.79 apiece, as opposed to $37 apiece plus shipping for fiberglass elbows. We walked out and my wife was like "That's it?".

Thanks for the tip on the PVC stuff Woodski!

[Michigan boarder]

I finished the fiberglass work last night. It really turned out well, much stronger than the original set up. Tonight I will paint the silencer with the hi-temp stuff I used on the other engine components. While it's drying I'll be installing that oil pressure switch and getting things cleaned up. Tomorrow is our 21 year wedding anniversary, then Friday I'll be back on the boat stuff, and will finish up all of the exhaust and the blower vent tubes. Mount the engine cover, install the tank, and set the timing.

I am heading to Sgt.'s place over Memorial Weekend for a water test & tune, the exact date depends on how the weather shapes up.

[2014Skier]

Looking forward to seeing the results of the water test...almost there.

[Woodski]

@M-B: You don't need to use hi temp paint on the silencer if you don't want to, it won't get very hot. You will notice the aluminum exhaust manifolds will run much cooler than your old case iron ones, the aluminum dissipates a lot more heat than the cast iron. Less heat under the engine box also helps reducing the potential for vapor lock on those warmest of days. I keep one of those thermal guns in the glove box for fun, you can check riser temps, oil pan temp and various checks to make sure all is happy in the engine compartment. I got mine on sale for $15 at Sam's (and could not resist), they are also available at Harbor Freight and various hardware stores.

Lets hope for good weather for the holiday weekend, it is Michigan so who knows what you will get...

[Michigan boarder]

@M-B: You don't need to use hi temp paint on the silencer if you don't want to, it won't get very hot. You will notice the aluminum exhaust manifolds will run much cooler than your old case iron ones, the aluminum dissipates a lot more heat than the cast iron. Less heat under the engine box also helps reducing the potential for vapor lock on those warmest of days. I keep one of those thermal guns in the glove box for fun, you can check riser temps, oil pan temp and various checks to make sure all is happy in the engine compartment. I got mine on sale for $15 at Sam's (and could not resist), they are also available at Harbor Freight and various hardware stores.

Lets hope for good weather for the holiday weekend, it is Michigan so who knows what you will get...

Thanks Woodski, I figured I wouldn't need the hi-temp but I've got extra anyways, and it will match everything else. Good idea on the thermometer, we actually have 6 USDA grade ones here that we use regularly, I'll try one of those out just for kicks to see what temps it is at.

Stupid fitting did not work on the oil pressure switch, the reducer won't clear the little ridge on the block above the oil filter, so I'm back to Napa again today.

Muffler painted up well, looks good. Double checked engine alignment, all good there. Also - I put a wrench on the bolts that fasten the engine mounts to the boat and most were loose. I never touched them before. So there are 2 bolts at 4 different corners, 8 bolts total with locknuts underneath. Only 2 of them were tight...but not wrenched down tight, got another 3/4 turn out of them. The other 5 were snug, got at least a full turn out of them, and 1 was loose, like 2 turns out of it. Never thought to check those before. Of course, they've got some corrosion too so now I'm wire brushing and painting them.

[oldjeep]

Stupid fitting did not work on the oil pressure switch, the reducer won't clear the little ridge on the block above the oil filter, so I'm back to Napa again today.

So just grind the "nut" on the reducer until it fits. Cut yourself a slot in the face if you have to so that you can use a chisel as a big screwdriver to install it.

[Michigan boarder]

So just grind the "nut" on the reducer until it fits. Cut yourself a slot in the face if you have to so that you can use a chisel as a big screwdriver to install it.

I thought the exact same thing! I'm going to exhaust the Napa possibilities first.