Dukemastiff

yep. I guess if it's good I'll get another 502.

sunbather1969

I have a 28' eliminator with twin 496 hos and xrs, there's something to be said about reliable stock power that does 95 on gps any day and i put 80 hrs a season on and need that. Not saying you can't do that with a 502.

thirdchildhood

iTrader: (6)

Because they stopped making them. They were good engines left stock but not very strong for SC. Performance parts are getting harder to find also. Even Raylar stopped making the sheet metal intakes.

thirdchildhood

iTrader: (6)

I went with the 502 based 525 after talking to a lot of people and the consensus even years ago was to lose the 496 in favor of a 502. Now, sure enough, the 496 has been discontinued and the 502 is back.

boatnt

iTrader: (1)

The 496 was dropped by Merc because GM stopped making the 8.1 engine ,which is what the 496 is based on,GM dropped the 8.1 because of fuel economy and replaced it with the small block 6.0, which in my opinion are just as bad in fuel economy,had nothing to do with 8.1 issues,I have been with GM for 35 years we had very very few issues,

The old 502 was a very good engine because of the internals,
the 496 is a great engine as long as you leave it stock,as far as technology goes,the 502 does not come close to the 496,

as far as your statement that the 496 has been discontinued and the 502 is back, you are wrong if you are saying this was done because the 496 had issues and the 502 did not,
and if you due some research I think you would find the new MERC 8.2 is different than the original 502,,

AZ Boater

You can actually get brand new 496 and 496 HO through Quicksilver. Mercury is casting their own blocks and builds completely dressed new engines. I just purchased two and repowered my Sunsation 32 with them.

BUP

iTrader: (9)

The 496 8.1 --- GM stopped all production Dec 31 2009 and that's why the 496 went away. Merc opinion was always that the LS engine would not last in a marine app especially in a sport boat nor have the amount torque to make anyone happy in stock form. With that said I want to back up a year or 2 from those Merc statements --- Merc actually even made statements that they were coming out with LS based engines way back in 2009 but dropped all that. I know I have the memos.
The NEW Mercruiser 8.2 L catalyst engine is not anything from GM period. The block itself is Merc design but made here at a foundry in the USA. Like I said the 2010 to current 8.2 Mercruiser DOES NOT HAVE ONE GM part installed. I know cause I had this engine torn down to the very last rod bolt not once not twice but a handful of times. And the same with the 496 torn down but at least 100 times since around 2002 - (The 496 came out for year model 2001).


IMO I would take the Gen IV big block and go to town with that. Even take a 454 GEN IV --- bore and stoke it to a 496 before buying and trying to hop up a 496. I am not a fan of hot rodding a 496. Way back in the past we had groves coming in wanting more power and speed for their 496. After about a year of this and that - I changed my mind about any changes to the stock 496's. I did not want to be married to that boat owner cause most of the time nothing was gained and or the reliability was completely taken away from the marine 496 's. Keep in mind Mercruiser was not the only one doing 496's in marine trim. I seen and worked on all the marine manu s who marinized 496 's including the exclusive GM 496. I will say around 2006 / 2007 many boats had 496 s including many production boats - even Sea Rays - Cobalts - crownlines -

Raylar stopped with some parts because those parts were not selling in any form of volumes. The 496 is really good at low end and mid range but top end not as strong. IMO weak.

BUP

iTrader: (9)

They are Dart Gen VII blocks. Merc does not cast the 8.1 but they do sub out the 4.5 L and the 6.2 L and the 8.2 L to a USA foundry for their own design

bck

BUP, did Merc make any improvements on the GM design when they went in house?

BUP

iTrader: (9)

The current 8.2 L from Merc is really nothing special. Internally nothing special either. The first 5 years of Merc 8.2 engine there was some issues.. And of course the GEN 3 cool fuel was used that created a lot fuel related issues as well. 3 cats in each exhaust manifold for a total of 6 did not help matters either. That was for 2010 thru very early 2014 models. .Keep in mind this is Merc exclusive 8.2 designed block and engine set up and zero GM parts. The block is Not GM either for this current 8.2. Merc does not even call it a 502 when talking about it.

Going back to the 8.1 --- the Dart 8.1 Gen VII block offers some improved upon compared to the GM 8.1 Block. If I recall correctly 2 others or maybe its one other makes the 496 block -- I do know for fact Dart and what to say Merlin or something with Bill Mitchel making 496 blocks. Dart 4 sure thou and there is one other if not 2 others making 496 blocks.

The very first 496 s HO did have a forged crank back in 2001.. But that was very limited runs for 2001. And again it was only the HO versions of the 496... . Also I seen 2 early GM - 496 blocks crack in front of the motor mount area as it has been said a few were weak in that area. If I recall there were other people that mentioned the same thing about that issue and it might have been up here years ago.

Keep in mind Mercruiser is the only marine OEM doing Big blocks no other marine engine manu is using big blocks period nor even selling repowers for their past engine line ups. except Merc.
Volvo Penta you can get a repower 496 for their past engines.