fastestonehere

Building a 496 not stroking just enough boring to clean cyl.
Reusing crank, rods with new fasteners, new forged pistons
roller rockers and a carbed intake manifold.

O.E heads with inconel exhaust Stainless intake, acompaning cam valve springs

This is replacing a merc 340 so im unsure about water flow rerouting?
open cooling so how do I mount 2 things the seawater pump and the alternator
The belt routing and and such.

Anybody have any pictures of a repower with a carburated 496. Open cooling
Also what size carb would you guys suggest. This repower will be redlined at 4400
Cursing around 3600 rpm's looking for the torque and a little more power.

BoneyardExpress

OK, Im a little bit lost, might need some more info. Are you replacing a 7.4 with this 8.1? Was the your old engine set up for serpentine belt or v-belts? Im assuming you dont have the factory Merc serpentine set up for the 496.. I would probably try to source a serpentine set-up for either a 502 or 454 MPI. The 496 looks like it has more pulleys and everything is more expensive to get your hands on for that engine. I was under the impression that the accessory mounting points were the same on the 8.1's as the older 502, and 454, but I have not physically bolted one up.

fastestonehere

I will be trying my accessories from MKIV block this week but the 496 has a cross over water tube from head to head interfering with brackets and the 496 also does not have water passages in head to intake manifold. Making the water neck/thermostat routing from MKIV to gen VII differant! It does appear that the GenVI timing cover fits with timing tab and the damper also the exhaust manifolds. I need to figure alt.bracket and seawater pump bracket and some way to tension them?

Accessory bolt holes on 496 appear to be off a little from MKIV head holes.