Difference Between Marine and Automotive Parts
Difference Between Marine and Automotive Parts – Video Transcript
Good afternoon my name is Bill Walker from Sierra International and today we're going to talk about Marinization.
One of the most frequently asked questions that we get in the marine industry is why can't I go down to the local auto parts store and buy a part similar to what you see here on the table that you're gonna find on your automobile or your pickup truck. Why is the price so much cheaper when I go to the auto parts store? Even though they may look similar keep in mind that these components that are designed for the marine industry and the marine environment are vastly different than what you're going to find in the automobile industry. One, they're designed for maximum longevity and two they're designed to protect you and your family while you're out boating.
So let's start here and talk about starters here we have a marine starter and an automobile starter. A couple differences that you can see, one is the paint process this marina starter has an epoxy coat where this automobile starter just a regular paint. That epoxy coat is going to protect this starter in the harsh water environment. It's also sealed at certain points to keep water from intruding into this starter. You can see that on this case there's spot welds here to keep this case from splitting under usage. The automobile industry they do not do that welding so under use this can actually spread apart and allow sparks to enter into the bilge. Anytime you get sparks entering into a bilge that is a bad situation because that's when explosions can occur. Along with that explosion protection this marine starter down in here and you can't see it but there is a plate separating the body from the nose. Therefore if there's an explosion or a spark it is contained within this unit. this automobile starter does not have that same protection.
Moving on to water pumps, here we have a marine version and here we have an automobile version. First and foremost, the backing plate this backing plate on an automobile version is stamped steel it's going to rust when you get it wet. The marine has a stainless steel backing plate to stop corrosion. The other thing is the paint process, the automobile water pump comes with no paint and no epoxy so it's going to corrode and it's going to rust. The marine water pump has an epoxy coating and that's gonna keep corrosion down. All the components are brass or anodized to keep that down and most importantly is the impeller. You can see on this automobile water pump this is a stamp steel impeller. Since in the marine environment very likely they're not going to be running antifreeze this impeller is going to rust. With the water in a marine environment they use a brass bi-directional impeller to keep that water pump working for years to come.
Now moving on to the fuel pumps as you can see here this is a marine fuel pump it is a dual diaphragm pump where most of your automobile pumps are a single diaphragm. That's for high performance of usage and also in case one of these diaphragms rupture there is this bleed off line that you're going to actually plumb a fuel line from here back into the carburetor. Which we'll talk about here shortly. That in case in your automobile applications when you see a diaphragm rupture what you see is that fuel will actually spill onto the ground. You don't want that to happen in marine environment so they have this line here that'll keep that fuel contained either in the pump or in the carburetor and not in the bilge.
Now we have the marine alternator, now these alternators look very similar once again to the things you're gonna find on an automobile but there's two very important features. One, in the front there is a screen behind the fan and in the back there is another spark arrestor screen. This is going to keep any sparks contained that are created by this alternator. Contained within this unit you don't want a spark to enter into the bilge because it's very dangerous.
Moving on to a marine carburetor even though again it looks very similar to the automobile parts there's a couple things in here that keep this safe when you're out on the water. First and foremost is this overflow damn If you have a flooding problem in an automobile application you're going to see that flooding cover the carburetor down onto the intake manifold that could create a very potential fire hazard. So in the marine environment they have this added a dam in here. If this floods it will contain the fuel and channel it back into the carburetor. The other thing you're going to find is there's going to be your connection to keep the fuel pump line connected to the carburetor. We talked earlier, about the fuel pump if the diaphragm ruptures this is where that is connected. And finally if you were to take these throttle shafts out on this marine carburetor what you're going find is they're actually grooved. As time goes on and these throttle shafts wear and an automobile application you'll find the fuel puddling along these shafts and onto the intake manifold. This grooving on these throttle shafts keep that fuel working its way back into the throttle blades and keeps that fuel contained within that marine engine.
Finally we're going to talk about distributors we have an automobile application and we have a marine application. First thing you're going to notice is that the automobile application has a vacuum advance. That is a no-no in the marine industry because one spark can escape from this area where the vacuum advanced is attached and two the corrosion itself can attack this vacuum advance causing the distributor to not operate and function. The other thing you're going to find is this is a mechanical advanced distributor but it also has a performance curve. The operating ranges on a marine engine are vastly different from the automobile applications. So this is actually a higher performance version than a standard point setup. The springs on this are actually heavier so at higher rpm usage the points don't float. And finally back to spark protection you can see this marine distributor has a spark arrestor vent here where you will not find that on the automobile application. The caps on the distributors are also different on an automobile application we find that the caps are using aluminum terminals which are highly corrosive in the marine environment. The caps on a marine application are brass which are very good conductors electricity and also stand up very well to the harsh environment.
I know this has been a quick rundown but that is just some of the things we find different. This is basically just a tip of the iceberg on what makes a marine parts different from the automobile counterparts.