MerCruiser to Replace 8.1L with 8.2L Engines in 2010

[twocents]

MerCruiser has decided to make the switch in 2010. The 496 MAG and 496 MAG HO are out of the line-up, replaced by the 8.2L (502 c.i.) block with catalytic converters to comply with the new EPA and CARB exhaust emissions regs.

 

[RiverDave]

Thank you for the update!

RD

 

[RiverDave]

Please check your PM's.

RD

 

[69 1/2]

Wow, I thought the 502 was the old design block from decades ago and siamese cylinder bores. The 496 was the latest and greatest with longevity far beyond the 502/454 block using alum. heads, six bolt mains and complete cylinder flow cooling. Maybe they are doing it to get away from the closed cooling costs that the aluminum heads cause.

 

[92562]

It's because GM stopped casting the blocks.

 

[WACAT]

Wow, I thought the 502 was the old design block from decades ago and siamese cylinder bores. The 496 was the latest and greatest with longevity far beyond the 502/454 block using alum. heads, six bolt mains and complete cylinder flow cooling. Maybe they are doing it to get away from the closed cooling costs that the aluminum heads cause.

496's do not have aluminum heads. From Merc anyway.

 

[mjc]

502 was only produce for crate motors and boats was never in any production cars or trucks. 496 is just gone since there are no big block trucks left.

 

[69 1/2]

496's do not have aluminum heads. From Merc anyway.

I had one from Mercruiser and two from Crusader, both had aluminum heads. That was the reason for the closed cooling on 496s.

 

[WACAT]

I had one from Mercruiser and two from Crusader, both had aluminum heads. That was the reason for the closed cooling on 496s.

Can't say you did not have it. My understanding was Raylar was about the only source.

The two 496's that I had both had iron heads.

Are you sure you did not have a stroked 454 block.

Jeff

 

[92562]

Can't say you did not have it. My understanding was Raylar was about the only source.

The two 496's that I had both had iron heads.

Are you sure you did not have a stroked 454 block.

Jeff

Edlebrock also has a head for the 496. I do not believe GM has an aluminum head for the 496 (which is where Merc, Volvo, & Crusader get their castings). The 496 has some advantages with an unternally balanced crank, internal crank trigger, etc., but the 502 block is stronger.

my .02

 

[69 1/2]

Just looked at the Crusaders in my boat, the heads are indeed iron, it is the intake manifold that is the shiny bare metal (aluminum). That is the reason for the standard closed cooling I guess.

Too bad if they are going to get rid of that block, in big boats we were always told to get ready for a rebuild at 1,000 hrs. but with these new blocks everyone said 2,500 hours. Mind you we run 28,000 lbs. of boat against them in a twin application and rarely turn them faster than 3,750 rpm. Lots of gas with little speed, my boat goes 26mph with both engines turning 3,750.

The 502 with it's siamese bores and forged pistons was notorious for oil consumption, people with big cruisers enjoyed the power but were really not used to getting in the engine compartment that often to pull the dipstick and add oil often at 15-20 hour increments. Saw several that were killed by lack of oil. That's what you get with a round hole and an oval piston.

 

[farmo83]

Whats the HP rating with the cat ?

 

[Duffster]

This is good news the 8.1 496 is a cheap pile of shit with cast everthing.
Why do you think merc stayed with the 8.2 502 block for HP line.

 

[Ultra26 # 1]

This is good news the 8.1 496 is a cheap pile of shit with cast everthing.
Why do you think merc stayed with the 8.2 502 block for HP line.

Don't be surprised of the new 502's use similar cast parts to the 496

 

[Outnumbered]

Dual cats under a closed engine hatch=damn hot:hotdevil:hotdevil:hotdevil

Probably have to install some type of cooling fans too...sounds spendy and heavy:thumbsdown

 

[RiverDave]

Dual cats under a closed engine hatch=damn hot:hotdevil:hotdevil:hotdevil

Probably have to install some type of cooling fans too...sounds spendy and heavy:thumbsdown

They are waterjacketed like on the new 496's...

I was asking BB572 about the carb 496's and he was saying you can't put headers on them etc.. Or it'll put the computer in limp mode. Total pain in the ass.

rD

 

[Outnumbered]

They are waterjacketed like on the new 496's...

I was asking BB572 about the carb 496's and he was saying you can't put headers on them etc.. Or it'll put the computer in limp mode. Total pain in the ass.

rD

I figured they would be water jacketed but it seems like they would still put out some major heat, especially if shut down right after a speed run.

 

[Duffster]

Don't be surprised of the new 502's use similar cast parts to the 496

You are correct maybe made in China to.

 

[BajaMike]

502 was only produce for crate motors and boats was never in any production cars or trucks. 496 is just gone since there are no big block trucks left.

The 6.0 isn't a "big block". I'm don' t know how to convert liters to inches.......:readpb:

 

[Ultra26 # 1]

The 6.0 isn't a "big block". I'm don' t know how to convert liters to inches.......:readpb:

I think the 6.0 is 364CI. The 6.2 is just short of 377.

 

[BadBlown572]

Dual cats under a closed engine hatch=damn hot:hotdevil:hotdevil:hotdevil

Probably have to install some type of cooling fans too...sounds spendy and heavy:thumbsdown

I was actually surprised on the temperature of the exhaust on the C.A.R.B. approved 496. It was warm, but I was able to put my hand on it with no problems. Wasn't noticeably different than a non C.A.R.B. approved 496.

 

[farmo83]

Aren't the blocks different? I thought the 496 was based on the old 427 tall deck truck engines and the 502 was based on the 454 ?

 

[69 1/2]

Aren't the blocks different? I thought the 496 was based on the old 427 tall deck truck engines and the 502 was based on the 454 ?

The 496 was an all new design, nothing before was like it. I'm sure GM just simply finds it way too expensive to make this engine for the rec. vehicle market alone since it is not in trucks anymore. Great engine but quite expensive vs. the old Mark series big blocks designed decades ago. Big step back in quality and especially longevity but it is a financial decision. They can build the old style blocks and heads for a fraction of the cost of these 496 engines.

My business manufactures gasket adhesives and non stick gasket coatings for the big three and beyond. All of the automotive manufacturers are now touting the new operating temps of 377F and we are scrambling to develop the coatings. I can't wait to see what that will do to the marine market. Get ready for lots more outboards.

 

[Outnumbered]

The 496 was an all new design, nothing before was like it. I'm sure GM just simply finds it way too expensive to make this engine for the rec. vehicle market alone since it is not in trucks anymore. Great engine but quite expensive vs. the old Mark series big blocks designed decades ago. Big step back in quality and especially longevity but it is a financial decision. They can build the old style blocks and heads for a fraction of the cost of these 496 engines.

My business manufactures gasket adhesives and non stick gasket coatings for the big three and beyond. All of the automotive manufacturers are now touting the new operating temps of 377F and we are scrambling to develop the coatings. I can't wait to see what that will do to the marine market. Get ready for lots more outboards.

377* --- wow--that is way up there. What is the reason? Cleaner burn at the higher temp?

 

[Outnumbered]

I was actually surprised on the temperature of the exhaust on the C.A.R.B. approved 496. It was warm, but I was able to put my hand on it with no problems. Wasn't noticeably different than a non C.A.R.B. approved 496.

Sounds like they did a good job engineering the cooling:thumbsup

 

[69 1/2]

377* --- wow--that is way up there. What is the reason? Cleaner burn at the higher temp?

It is 100% emissions.

 

[Waterjunky]

The 6.0 isn't a "big block". I'm don' t know how to convert liters to inches.......:readpb:

One liter = 61.0237........... cubic inches

If the 6.0 is exactly 6.0 then you have 366.1424 inches

 

[69 1/2]

One liter = 61.0237........... cubic inches

If the 6.0 is exactly 6.0 then you have 366.1424 inches

And the 302 Ford engine rounded to 4.9 liters but they called it 5.0 for marketing reasons.

Side note, I remember the old SS Chevelle 396 sported a 427 for at least one year but was still called an SS 396.

Funny how it all comes together.

 

[Ultra26 # 1]

One liter = 61.0237........... cubic inches

If the 6.0 is exactly 6.0 then you have 366.1424 inches

You're right. I believe Chevy's "6.0" is a bit short of 6.0, at 364CI

 

[farmo83]

and ford called the 300 I-6 the 4.9 liter. Stout little engine. I had one in my first truck.