Difference between Mercruiser 496 and 8.1

M

mrsrobinson

Well-Known Member
Mar 9, 2006
7,704
Virginia
Boat Info
2001 380DA
Engines
Caterpillar 3126
I have looked at a lot of early to mid 2000s cruisers over the past few months. I noticed the Formulas have a Mercruiser 496, while the Sea Ray's and Cruisers Yachts have a mercruiser 8.1. I've done a Google search to figure out the difference and haven't come up with anything, does anyone know the difference?
 
Same motor except they called it a 496 when paired with a Bravo III Outdrive and called it an 8.1l when used in an inboard configuration. The only differences would be what is needed to pair them to the associated drive system.
 
Jeremygavin said:
Same motor except they called it a 496 when paired with a Bravo III Outdrive and called it an 8.1l when used in an inboard configuration. The only differences would be what is needed to pair them to the associated drive system.
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Thanks, this makes sense because evey one I saw with 496 was paired with a bravo 3
 
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There are also two HP versions of 8.1s. Crusader 8.1s are preferred over Merc because they are much easier to service and have more robust water pumps that do not require routine replacement. (Stainless housing with bronze impellers instead of plastic stuff.) Impellers are also easy pezzie to change out.
 
sbw1 said:
View attachment 75600 There are also two HP versions of 8.1s. Crusader 8.1s are preferred over Merc because they are much easier to service and have more robust water pumps that do not require routine replacement. (Stainless housing with bronze impellers instead of plastic stuff.) Impellers are also easy pezzie to change out.
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Do you know if there is an aftermarket option for the Mercs to upgrade to stainless/bronze?
 
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mrsrobinson said:
Do you know if there is an aftermarket option for the Mercs to upgrade to stainless/bronze?
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No. Do not know. Two different companies so switching things among the two is likely a problem.
 
mrsrobinson said:
Do you know if there is an aftermarket option for the Mercs to upgrade to stainless/bronze?
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Hardin Marine makes a SS water pump with replaceable wear plates to fit the Mercruiser but I had bearing issues with the first set of them I put on. Hardin warranted the pumps but there was still labor involved in changing them out. The second set I didn’t have the same issue but I didn’t put as many hrs on them before I sold the boat so I am not sure of the longevity of them.
 
It's not so much how the Merc's pump is made, but where it is compared to the Crusader. The Merc's is a belt driven pump that is under left side of the engine as you look at the pulleys on the front of the engine. Not a big deal on my straight shaft boat with 3' of room between the front of the engines and the firewall, but can be a challenge with V-Drive boats. That being said, the entire pump needs to be removed to replace the impeller. I believe Crusaders are run off the crank pulley (front of the engine) and the impeller can be removed by taking off one simple access plate - a much better design.
 
mrsrobinson said:
Do you know if there is an aftermarket option for the Mercs to upgrade to stainless/bronze?
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The latest merc seawater pumps have stainless end plates, so that is one wear issue resolved. I am also my advised by my merc tech that the end plates can be installed in the old pumps and run a slightly smaller impeller to compensate for the plate thickness.
 
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