INDMAR CATALYST

How do you know your INDMAR CATALYST Engine is properly functioning? You know, no "CO", Use of a Canary?

place the Canary in a cage, secure the cage to the bottom of the swim deck. If teh Canary dies, it's not working.

You do raise an interesting question. If one was going to teak surf behind a Catalyst engine you'd want to be sure it's functioning properly. I have no answer.

ok I'll go first..., what the heck is an Indmar Catalyst engine?

Indmar decided to put catalytic convertors on their 5.7 Monsoon engine they supply to Malibu for 2007.

From the Malibu Website:

"The Monsoon 340 (340 HP) delivers out of the hole with 397 foot-pounds of torque. This customized version of GM’s Vortec 5.7L is designed specifically for Malibu’s performance hulls. The new Indmar ETX/CAT one-piece tuned exhaust manifolds reduce Monsoon emissions to almost nothing. Add high lift roller cam and free-breathing Vortec heads and this engine equals one of the most powerful, dependable small blocks ever built. "

I know Supra is doing this also. Engine sounds pretty cool. It is a little different as you hear a boat go cruising off.

Mine has it. Sounds great. Kinda like the 2006 GTO if I had to compare it to a car. Plus it has some green stickers on it that make me feel real good about the environment while I am burning 7-8 GPH of fuel.
http://www.wakesiderides.com/rides/index.php?page=out&id=2178

EMmmm.... Feel good green stickers! Burns the same as none cat. Oh yeah baby. Pull on!!!

All PREMIUM engines from Indmar for the 07' model year are catalyst equipped. This is true for all 3 manufactures that use Indmar (malibu, master craft, and supra/moomba). Next year Indmar will be required to produce 100% catalyst, they went with a faze in option instead of going all in for 08' model year. This holds true for all inboard and outboard engine manufactures for the marine industry. The engines actually gained performance due to the closed loop O2 system that the catalyst yielded, instead of loosing due to increased exhaust restriction. The converters added very little cost to the engine, made them more power full and more reliable due to better technology being used on those engines.

Dang Roy,

I am sure PCM will have this out in the future as well. Hope you are doing well.

Rick

Man, I hope they are more durable than the vehicles equiped with catalysts that I deal with. Hopefully they've got the heating/cooling, expansion/contraction thing figured out. Nothing worse than having another expensive part on the a marine engine to fail. I think its a decent idea, but I hope they did enough R&D.

(Message edited by guido on October 19, 2006)

(Message edited by guido on October 19, 2006)

Mercruiser and PCM are behind on there product development. Indmar has had catalyst on engine for a while now most of them with over 500 hours and 0 failures in salt water and every enviroment you could think of. The catalyst has actually been around for 10 or so years but until California emissions set a date on it, there wasn't a big push to do anything about it.

This thread started out asking about CO emissions, and even a reference to teak surfing. Just so there is no confusion, don't all internal combustion engines put out CO?

It's great that Indmar is going green and reducing harmful emissions, but no one should be under the illusion that it is safe to breath the exhaust.

Ha I do find it funny that I open the hatch on our '07 X-star with the 8.1 and see a sticker stating that it is a certified Low emissions vehicle. Our first Mastercraft a direct drive 454 '89 Maristar 240 would literally knock you out if you took to long getting strapped in on the platform. Cheers for cleaning up, Matt

Rich, that's the point of a catalyst. It converts the CO, HC and Nox to non-harmful elements like H20. I don't know the specifics (I really should, since it's my job... LOL). Anyway, a properly catalyzed engine with current technology will be soo clean out the tailpipe that you could run it in a sealed garage and you'd be just fine (so much for easy suicide's). Saab actually did a test a couple years back in NYC. They found the air out the tailpipe of their cars to be cleaner than the air on the sidewalk. I doubt a boat would be that clean (due to the lower technology fuel injection), but it's a step in the right direction.

(Message edited by guido on October 20, 2006)

I guess the cats are located somewhere before the cooling water enters the exhaust? If so, then O2 sensors would be easy to install, and closed-loop mode EFI isn't far off.

This is all good stuff, but I don't think I'll be teak surfing or testing the sealed garage theory any time soon.

They already have closed loop O2. That is the whole gain to using cat's. The manifold looks like a big header, then the tubes start to merge and there is the O2 sensor. Directly after is the cat, and then into a stainless steel elbow where water is introduced for cooling. I will post an attachment showing the cat.

I wonder how useful Closed Loop efi would be on a boat. In traditional automotive EFI, the closed loop doesn't kick in until the car's RPM and speed have stabilized, like on the highway. Once things have stabilized the car begins to fine tune the mixture. When you're driving around town and accelerating, the computer refers to a preprogrammed map for fuel mixture settings.

I don't know about you, but constant speed boating represents 20% of my boating time. Maybe I need to pull better riders? I think most of my fuel is burnt driving the boat from 0mph to plane. Don't get me wrong, I think there is a fuel econ gain to be had, but I'd guess it to be the difference between 7GPH and 6.9GPH.

Any savings is going to be washed away the moment my boat throws the dreaded "Check Engine" light and I have to replace marine O2 sensors at probably $350 each.

Found this on 'how stuff works', it appears to be more of a sales pitch than anything, since the operation of the converter is variable. It may or may not remove the poison from the exhaust.


The main emissions of a car engine (or boat for that matter) are:

Nitrogen gas (N2) - Air is 78-percent nitrogen gas, and most of this passes right through the car engine.
Carbon dioxide (CO2) - This is one product of combustion. The carbon in the fuel bonds with the oxygen in the air.
Water vapor (H2O) - This is another product of combustion. The hydrogen in the fuel bonds with the oxygen in the air.
These emissions are mostly benign (although carbon dioxide emissions are believed to contribute to global warming). But because the combustion process is never perfect, some smaller amounts of more harmful emissions are also produced in car engines:
Carbon monoxide (CO) - a poisonous gas that is colorless and odorless
Hydrocarbons or volatile organic compounds (VOCs) - produced mostly from unburned fuel that evaporates
Sunlight breaks these down to form oxidants, which react with oxides of nitrogen to cause ground level ozone (O3), a major component of smog.

Nitrogen oxides (NO and NO2, together called NOx) - contributes to smog and acid rain, and also causes irritation to human mucus membranes
These are the three main regulated emissions, and also the ones that catalytic converters are designed to reduce.

The reduction catalyst is the first stage of the catalytic converter. It uses platinum and rhodium to help reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom out of the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2. For example: 2NO => N2 + O2 or 2NO2 => N2 + 2O2

The Oxidization Catalyst
The oxidation catalyst is the second stage of the catalytic converter. It reduces the unburned hydrocarbons and carbon monoxide by burning (oxidizing) them over a platinum and palladium catalyst. This catalyst aids the reaction of the CO and hydrocarbons with the remaining oxygen in the exhaust gas. For example: 2CO + O2 => 2CO2

The catalytic converter does a great job at reducing the pollution, but it can still be improved substantially. One of its biggest shortcomings is that it only works at a fairly high temperature. When you start your car cold, the catalytic converter does almost nothing to reduce the pollution in your exhaust.
One simple solution to this problem is to move the catalytic converter closer to the engine. This means that hotter exhaust gases reach the converter and it heats up faster, but this may also reduce the life of the converter by exposing it to extremely high temperatures. Most carmakers position the converter under the front passenger seat, far enough from the engine to keep the temperature down to levels that will not harm it.

Preheating the catalytic converter is a good way to reduce emissions. The easiest way to preheat the converter is to use electric resistance heaters. Unfortunately, the 12-volt electrical systems on most cars don't provide enough energy or power to heat the catalytic converter fast enough. Most people would not wait several minutes for the catalytic converter to heat up before starting their car. Hybrid cars that have big, high-voltage battery packs can provide enough power to heat up the catalytic converter very quickly.

Craig, that isn't true anymore. Most systems go closed loop within 30 seconds of start-up and only drop out under full throttle application (where it goes to a WOT map) or upon returning to idle. If Idle is sustained, then they go back into closed loop after a very short period. I'd be more concerned about the sensative electronics associated with a MAS system on a boat. Air filters would have to be better. Boat tech's would actually need some diagnosis skills and water tests would be more prevalent. It just adds a bunch of complications.

As far as the Cat's go... The only real problem I see is with the additional heat they create. Cats typically operate around 500 degrees externally (that's with air to cool them). Hopefully the water will work well, otherwise there are going to be some seriously hot boat engine compartments.

BTW, BMW went to the electrically heated cats for a short period in their V12's. What a joke that system was. 100+ amps going to heating elements with their own dedicated battery. Way more complication than necesarry. Probably made the cats light off only a fraction of a minute sooner. Oh how I love the BAR.

FYI, my engine compartment does not get hot with the cats. These pictures are from Malibu's website. The O2 sensors are beside the water inlets on the headers. They look very easy to replace, should they ever need to be. This is the "least smelly" boat I have ever been around. I didn't give the cats much thought (especially positive) when I was buying it, but in hindsight, I am glad it has them. In fact I am starting to get a little freaked out realizing at this very moment that the government made me do something that I am happy about. Now if we could just get them to quit picking on Willie.