Marine vs. Non-Marine

[AKBASSKING]

I want to open this up for discussion.

I had a port engine starter solenoid go bad. I looked at a solenoid from a marine dealer that cost $25.00. I went to my local automotive store and looked at one for $8.00.

They were the same identical part! There was no special seals or spark containment etc.

So what gives? I know some part, mostly electrical should be USCG approved and sealed for electrical spark. But when the part is exactly the same with the exception of the marine on the box who is ripping who off here.

Can someone explain the difference between marine spark plug wires and regular spark plug wires other than the price?

Look at a MerCrusier distributer cap and it looks just like a Chevy 350 distributer cap I can get at NAPA. Can someone explain the difference?

I am starting to get into my engine bay and I wanted to know the big differences between stock automotive parts and the high priced marine counter part. Please convince me.

 

[CSR_Admin]

I am not sure. But just to further the discussion maybe its about the distribution channels. The auto market is obviously infinitely bigger. Maybe since the boat market is so much smaller parts destined to end up in marine stores cost more because of the lower volume. A marine distributor might buy 30 of them at a time and send them out to some retailers. An automotive distributor might buy 30,000 of them at a time and send them out for retail.

 

[Bucit]

Years ago I had a trim solenoid go bad on my Johnson outboard. I went to a local automotive store and bought two. The part number and appearance were identical to the original. I installed it and never had a probelm (which was like 7 years later). Manufactures mark it "marine" so they can increase the price. IMO

 

[LTD.330]

How can you be sure it's identical on the inside?

I understand stretching a dollar, but when it comes to items that affect the safety and well being of my family, I'll go the extra mile every time. Even if that means overpaying for a "marine" part by 300%.

You never want to be in the position of wishing you bought the marine part.

 

[mfilippa]

I don't deal with Marine vs. Non-Marine, but have worked in products that came down the pipeline being identical, but one would be certified and the other wouldn't. The difference is a marking, UL, USCG, etc, and the ultimate difference will be whether you can sue the company or not in case of fire, based on that seal being present or not.

My 2c.

 

[AKBASSKING]

How can you be sure it's identical on the inside?

I understand stretching a dollar, but when it comes to items that affect the safety and well being of my family, I'll go the extra mile every time. Even if that means overpaying for a "marine" part by 300%.

You never want to be in the position of wishing you bought the marine part.

So qualify your statement.

Safety is the biggest concern. But when I look at a distributor cap from MM or WM and one from my local car parts store there is no difference other than the price.

I had my stbd starter rebuilt last year and when I asked the difference, the guy told me the sealant they use, that's it. The starter solenoid was identical.

Spark plug wires: Other than brands, what is the difference between the brand I buy at auto brand X and WM or MM? haven't been able to find one yet.

No one has been able to explain "why" other than as Jim stated is distribution.

 

[skibum]

For the same reason that you pay higher taxes if you earn more. Because you can afford it, and they don't mind making the "rich folks" (i.e. people who can afford boats) pay for it.

 

[Lazy Daze]

If the parts are truly identical, then I would agree with what Jim said. I would just make absolutely sure they are identical.

When I pulled my engine a few winters ago to replace the oil pan (too bad there wasn't a "trap door" in the hull bottom:smt001), I took the opportunity to replace a bunch of stuff while it was on a stand in my garage. One of those was the timing chain. The Merc timing chain and sprocket are 100% identical to a set you can get from Summit Racing, for example. Same GM casting numbers and everything... exactly identical. The Merc part was an honest 2.5x's as much. I did not buy the Merc part.

Especially with electrical stuff, just be 100% sure. 99% won't cut it.

 

[AKBASSKING]

Especially with electrical stuff, just be 100% sure. 99% won't cut it.

I agree with you 100%.

Although our engines operate with differant loads than an auto, the gas engine (Maybe even the diesel) was adopted from autos for boat use with a few modifications.

Of course I thought I would stirr the pot too (I am NOT the official pot stirrer though). I am surprised that some folks haven't tarred and feathered me yet.....

 

[fc3]

If you ever have a "problem" and the insurance company is looking for an excuse, having all marine parts removes one excuse from their potential list.

What Dennis said is absolutely true about non-electrical parts. The Mercruiser engine gaskets, for example, are the same as the GM ones. I know this to be true since they are sold in the orignal, sealed GM plastic envelope with the GM logo and GM parts number label. The only thing marine about them was Merc's label partially covering the GM one. I have a Delco Rochester 4BBL kit downstairs that's still Delco sealed and the only difference is the Merc Part number on the box. BTW, that kit is free to a good home.

Best regards,
Frank

 

[Dick Whetstone]

I personally think the same goes for engine oil --- for the most part. I have 3 boats all powered by Mercruiser engines. The 1965 classic Glassmaster 17 foot runabout has a 153 CI 110 HP Mercruiser and the 1986 Glassmaster Regency 21 foot cuddy cabin has a 350 CI (5.7 liter) 260 HP Mercruiser.

Both have been run from day-one with Shell Rotella 15W-40 diesel engine oil. The 1965 probably has 1500+ hours (no hour meter) and the 1986 has a documented 976 hours on the original hour meter. Neither engine uses any oil and both still run absolutely perfect. Both have just normal tune-ups and oil and filter changes and a carb rebuild every 15 years or so.

On the other hand, my 2001 270 Sea Ray Sundancer with single 7.4 has always used Mercruiser 25W-40.

Is the Mercruiser 25W-40 oil any better than Shell Rotella 15W-40 in marine applications??? I don't know. I can say I have had outstanding results with both oils. By the way, Shell 15W-40 oil costs less than half of what Mercruiser 25W-40 costs.

 

[Old Vet]

"By the way, Shell 15W-40 oil costs less than half of what Mercruiser 25W-40 costs. "

Just bought my first....AND LAST....single quart of Mercruiser 25W-40 oil..... $8.00 :wow:

Will most certainly be looking for a suitable substitute come the next oil change.

 

[dpmulvey]

My take is that if it makes a spark external to the combustion chamber, make sure it is certified for marine use. That certification costs a LOT of money hence the markup. As said, it takes away one thing the insurance company can deny you a claim. Beyond that, if it has a cross match, I use it. The Volvo outdrive on my Regal ended up with a set of John Deere U-Joints in it.

WRT oil; I know the Rotella used to be better, however, the addidives (ZDDP and sulphur) that kept it from breaking down have been reduced in quantity.



I would think Mobil 1 would be safe.

 

[Presentation]

"By the way, Shell 15W-40 oil costs less than half of what Mercruiser 25W-40 costs. "

Just bought my first....AND LAST....single quart of Mercruiser 25W-40 oil..... $8.00 :wow:

Will most certainly be looking for a suitable substitute come the next oil change.

Shop around a bit.

By the quart you can find it at $5.45. Even less per quart by the gallon.

 

[Daddubo]

Dealer prices are always higher no matter what and Marine dealers prices are FN Nuts. When you say Boat or Harley the price always goes up. There certain parts that are Marine specific but other than that engine parts are the same. The difference between a automotive engine and a marine engine are brass freeze plugs and stainless steel head gaskets other than that they are the same. They put 2 and 4 bolt main engines in boats just like cars; the carb is different due to chance of fuel over flow if the float sticks. I just replaced the heads on mine they are say PASS on them which means passenger and I ordered head bolts for a 87 GMC pick up. The spark plugs are SS so they don't rust in. So if it dosen't spark go for it.
As far as oil have you ever seen 25W/40 oil any where other than Merc? Rotilla T is an excellent oil it is Hi Detergent and made for the pounding a diesel gives most semi’s the oil is changed at 10K miles not 3K and some just do an oil sample and change filters. So if it dosen't spark or spill fuel go for it!:thumbsup:

 

[AKBASSKING]

The oil is intersting. My Merc engine manual says use a 30w oil, so I use Castrol and a Fram oil filter. Plan to install remote oil filters.

I also agree with the spark statements.

 

[AnchorsAweigh]

The difference between a automotive engine and a marine engine are brass freeze plugs and stainless steel head gaskets other than that they are the same.

You only missed one thing, they have different cams in them as well. Unless your auto motor is used in say a motorhome or tow truck, then it would have the same type cam. Marine cams offer high torque throughout the rpm range, hence tow truck etc. Someone once said a boat motor is under a load like a pickup truck with a camper on it, pulling a big boat, and going up hill ALL the time.

I agree with what all the guys are saying too, just be 100% certain it looks the same and it will be the same. I've used auto solenoids for trim units, auto spark wires (premium sets only), and distributor parts as well. One time there was a cap that had a vent in the side but we sealed it with epoxy and used it for a while till getting the proper auto one. It was an occasion where if we didn't use it than we would be towing a long long way home.

Lastly, I guess I would add that although sometimes sh*t happens if anything fails under the hood (or hatch) I look at myself first as to what went wrong and not an issurance company or part manufacturer.

...my two pennies...

 

[rcknecht]

It would be nice if we had an unofficial CSR cross reference for parts, such as westerbeke oil filter and plugs to automotive. I found out today that the same filter I use in my honda will work in my genny. It could be swim at your own risk list...

 

[fc3]

Your Mercury manual has been superseded. Check the oil FAQ on the Mercury website.

There's no difference in GM engine's camshafts between what GM installed in vehicles and boat builders installed in boat. Oh maybe way back in the 70s and maybe even the 80s there were, but I doubt that there's been any difference between a marine or land-going 350 or 454 in the last 20 plus years. It's been a heck of a long, long time since you could walk into any automobile showroom and purchase a passenger car with a big block V8. 1978, I think. They're all truck engines.

 

[JVM225]

When the automotive parts and marine parts are identical, go woth the automotive stuff and save the money. Just make sure they are identical.
I use automotive oil and filters in my boat with no problems. I get my spark plugs from the auto parts store.
Many internal engine parts are exactly the same. There is no difference in the material a cam is made of, but the lift and duration of a boat cam is probably closer to a truck cams specs than a car because the boat and the truck need the torque.