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Marine Catalytic Convertes


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I keep hearing about marine cats...

Does anyone have one?

Does it turn your boat into a Sea Slug?

What do they look like?

Are they water cooled?

Is the closed loop mode of MEFI used?

Enquiring mind wants to know.

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I keep checking Indmar's website to see if there is any news, as I've heard the Monsoon for 2007 will have the cat converters. That would be an Indmar issue vs a Malibu isuue, right? I, too, am very interested to see how they will pull this off.

Specifically, with the fact that cat converters operate at extremely high temperatures, I think around 6-7 hundred degrees, I don't see how they could be water cooled and maintain those operating temperatures. But something getting that hot in a boat is not good in my opinion. So how they address that will be fun to see.

I'm also curious as to how they will maintain the 340 horse, or close to it. I keep thinking back to the early 70's when they put the converters on vehicles and the horsepower dropped off the charts. I guess Indmar will have the latest automotive technology available to them, so the power may not be an issue.

But the temperatures will be...

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Supposedly, most if not all BU's in 07 will have cat's. I spoke with one dealer who has already had one out w/ a cat and said it feeled and acted pretty much the same as without.

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I found this paper on Microlith Converters

says "...applications include marine four-stroke engines..."

looks tiny enough to fit inside an ETX. Can you imagen what a new manifold is going to cost? ETX manifolds are $2500.00 An ETX/CAT will probably be double.. Cry.gif

I wonder if those are going to be required for Cali only?

edit: It appears to use a SiC Technology

Edited by MoonDawg
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I was told that the Monsoon will be the only engine for '07 to get the cats. After that, I don't know.

There's a picture in this post of the new cats on a Monsoon. Trentster can speak to how they perform in comparison with his "old" boat. I was told that they are water cooled, much like the old ETX manifolds, but how they work I don't know. I was also told that they won't be that much hotter in temperature than the old manifolds. That one raised my eyebrows, but we'll see. The other thing that I was told is that they reduce emissions by 75%. Maybe Trentster could give us a full report. :)

Here's the pic:

DSCN2903.jpg

Edited by WakeGirl
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I wonder if those are going to be required for Cali only?

Here's the funny thing Dawg,

Boats and motorcycles are never emission tested in California. In fact, I doubt boats are emission tested anywhere due to the water that comes out w/the exhaust. So, I can forsee some company making a cat converter "test pipe" and guess what? A lot of people will remove their manifolds and retro to non-converters if they think they're losing any HP.

Sadly, there is this huge stigma that just because you're installing a "blockage" in the exhaust system that you will automatically lose power...

I spoke with one dealer who has already had one out w/ a cat and said it feeled and acted pretty much the same as without.

I was looking to buy a 2001 (I think) Honda VFR motorcycle awhile back. It just so happen that it was the first year that they put a cat on the bike. The dealer told me that even though they put the cat on, the bike gained something like 3 HP. Now, as far as heat, I don't know how that's gonna play out. The internal temp. of a cat can be close to 1000F, the external temp. of an automotive cat can be close to 500F

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I wonder if those are going to be required for Cali only?

Here's the funny thing Dawg,

Boats and motorcycles are never emission tested in California. In fact, I doubt boats are emission tested anywhere due to the water that comes out w/the exhaust. So, I can forsee some company making a cat converter "test pipe" and guess what? A lot of people will remove their manifolds and retro to non-converters if they think they're losing any HP.

Sadly, there is this huge stigma that just because you're installing a "blockage" in the exhaust system that you will automatically lose power...

I think that they're hedging their bets that the EPA will start emission testing & thus trying to gain a foothold. As for the power loss, there's plenty of history there, with what happened to cars & trucks when cats were first introduced. That doesn't necessarily equate, I know, this is 2006, so the technology is there. But for those of us that saw what happened when the first cars were given cats, it's a hard perception to overcome. I'm personally not tempted to believe at least some of what I've been told, merely because the first rendition of a new technology is almost never the final product, but I'm withholding judgement for now. We'll see.

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I skied behind an MC with the cats installed last weekend. It was a prostar 197 with the MCX 350 hp and the Power Slot 1:125something gear reduction tranny. It was quite impresive, I thought my arms were going to fly off. It had a really impresive pull also, no give, it was not a soft pull thru the course at all. BTW this was one of 3 boats going to the us open for the tournament.

The guys driving the boat mentioned the increased temps, but said that they were not transfered into the engine compartment, and that the manifold design was actually a few degrees cooler then the older versions. I like the idea of decreased pollution, but I doubt that adding these devises will really have much effect in the overall picture of our air pollution.

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From the Indmar News Release in post #5:

"The most dramatic achievement for boater safety is ETX/CAT’s substantial reduction of carbon monoxide (CO) gases in all part-throttle operating modes. "

My boat rarely sees "Part -Throttle" operation Biggrin.gif

Maybe Teak Surfing will be legal on an boat with Marine Cats.

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i saw a 2007 with the cat on it. they look weird but the dealer said it is going to be manditory in about 2 to 3 years so malibu started putting them on now. as for horse power malibu got lik 4 to 5 more horse power out of it sounds strange but that was the words out of the dealers mouth...

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I didn't notice any loss in power at all. My 2005 V-Ride had a Monsoon 340 with a 537 prop on it. My 2007 VLX has the Monsoon 340 with ETX Cats and Silent Tip Exhaust. It's super quiet and has a better holeshot than my V-Ride did even though it weighs 600 plus pounds more. Keep in mind though that I have a 1235 prop on my 07 VLX.

If you look at the picture of my motor that Traci posted you can see the 02 sensors on the top of the cats. This is suppose to increase full efficiency.

I've touched the exhaust when the motor has been running hard, and it doesn't seem to get any hotter than the manifolds on my V-Ride.

This weekend will be the real test. I'll probably have ten or more people on it at any given time, and will likely have the ballast full too. My V-Ride handled 10 or more people just fine with 900 pounds of ballast, the wedge down, and an additional set of fat sacs under the front seats in the bow.

Trentster Rockon.gif

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...If you look at the picture of my motor that Traci posted you can see the 02 sensors on the top of the cats. This is suppose to increase full efficiency. ...

Ahh so they are running closed loop. That should really help with the fuel economy. :)

You might be able to do some motor mods now. Like run the hot cam from the 383 Hammerhead and have the MEFI compensate.

EDIT: Is the O2 sensor connected to the cable that loops over the top of the intake? Seems like they would want one on both sides.

Edited by MoonDawg
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...If you look at the picture of my motor that Traci posted you can see the 02 sensors on the top of the cats. This is suppose to increase full efficiency. ...

Ahh so they are running closed loop. That should really help with the fuel economy. :)

You might be able to do some motor mods now. Like run the hot cam from the 383 Hammerhead and have the MEFI compensate.

I was thinking the same thing. That's a good move. The closed loop will definitely help with fuel economy, and will also improve emissions a great deal by themselves. These engines have always run rich.

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Trentstor,

Is there any mention about the MEFI version? I know that Rinda is now developing a version of Diacom Marine for the MEFI 5. They published this newsletter stating that Indmar would be using the new module but I have never seen anything confirming it was on the newer engines.

If it is that is great! It uses the CAN-Bus interface. That is an open standard so perhaps we will actually be able to buy a low cost engine monitor for our boats instead of a plug with a blinking light. Diacom is still $700 that is more than I want to spend Cry.gif

The new MEFI 5 uses sequential injection so there should be more control over the fuel delivery to each cylinder.

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But I thought cats were in place to reduce HCs?

You're right. CAT's will have no effect on the CO emissions.

This is not your tired old automotive Cat...there is a new SiC Cat in town. Biggrin.gif

Edited by MoonDawg
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.... malibu got lik 4 to 5 more horse power out of it sounds strange but that was the words out of the dealers mouth...

Maybe the Sequential Fuel Injection has more to do with the HP increase than the Cat.

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But I thought cats were in place to reduce HCs?

You're right. CAT's will have no effect on the CO emissions.

This is not your tired old automotive Cat...there is a new SiC Cat in town. Biggrin.gif

I don't see anywhere on that site that says it reduces CO. They do say that it will reduce solids which will reduce polution. CO is a byproduct of combustion that isn't removed from a catalytic converter. If people think that there is greatly reduced CO from this system, they might think that they don't have to worry about CO poisoning anymore and that certainly is not the case.

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I'm a bit confused. If the new engines have 02 sensors, that's great, they need them.

But, looking at your picture and guessing where the sensors are, it seems that they are down stream from the water going into the manifolds. If those are actually 02 sensors, they're not going to work with water going by. Can anyone verify those are 02 sensors?

post-29-1157048280_thumb.jpg

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