Supercharging 6.2l Mag engines
 

Not sure if this is a good idea. Have messages to Wipple and Young Marine to see if there is a package that works with engines equipped with catalyst exhaust. Seems that there are packages for the everything non-catalyst exhaust, and maybe the 350 mag with ECT....but nothing out there for the 6.2l Mag.

I have thought of an engine exchange, even to an LS platform, but the cost is just too high. The idea of a supercharger seems like a good one from a cost standpoint(compared to engine replacement). Of course, the goal would be to not have a serious impact on durability of the package. Engines currently have around 125hours on them, so there is a lot of life left in them. Making sure there is a proven tune for the catalyst exhaust is another challenge.....and I do not want to be the test bed. I would like a mild addition of power(maybe +100HP from the stock 320) to 420hp. I think that this would make a BIG difference in the drivability of the boat, planning times, and to some extent, top end.

Any thoughts to share?

Whipple offers kits but they are pricey. My concern would be the stock pistons at anything more than a few pounds of boost.

Mercruiser warranty expired? Do any marine police have a way to check your emissions? Or even know the diff? Take the cat exhausts off and put them in the attic. Then get real exhausts and a better tune-fuel map.

That's a great package but I feel the original 6.2 is not strong enough for the superchargers . We've made good power with their set up . Here's something we've worked on which started life in the 6.2 but we had to step it up to get it to hold.

https://scontent-mia3-2.xx.fbcdn.net...48&oe=5A421AE9

Good morning Laz. Really enjoyed some of your recent threads in the Q&A section. I'm surprised the 6.2 isn't supercharged more in marine applications. You mention in your post above you had to "step it up to get it to hold". How involved is this? Pistons, connecting rods, crankshaft, valvetrain??? Also the OP mentioned a 100 HP a side is plenty. If you bolt on some intercooled Whipples with 4lbs of boost surely this would satisfy the goal. I use to track a supercharged Rousch Mustang with stock 4.6 and 4lbs of boost with zero issues for 18K miles. I know street and marine are apples and oranges but the track environment is a brutal environment as well.

I've been involved with several of the 6.2 upgrades in the past two or three years and though they make power I've seen piston issues . The blower package is a great piece and very capable of way more than 100 hp . If you do the upgrade make sure you install O2 sensors to monitor your mixture specially above 4300 RPM where the pump gas starts to show it's colors. This pic is a complete build there's nothing GM or Merc with the exception of the oil filter this package made north of 700 with 10 lbs . Best of luck. Laz

Pistons and 4.5 qt. oil capacity/no oil cooler are definite limiting factors on supercharging the 6.2L MPI in stock form.