how would I find built date on my 2002 496HO?

PA. Woodchuck,

I got the serial number off my transom assembly and called Merc tech. They apparently trace the builds. Assuming your engine and transom assembly have never been separated, they should be able to give you the entire build sheet.

Thanks. Brad.

BoatNT,

After a meeting with my welder contact, and a lengthy discussion on welding order of operations and a complete rethink on fixturing, we've got a plan in place. I've got a stack of prints for fixturing, a bill of material for said fixturing on RFQ, the AN weld-on bungs in hand and a bundle of 316 stainless seamless tubing on the way. This should be fun. :party-smiley-004:

Like I said, what I'm building will be two separate fuel rails, functionally identical to the OEM on-piece unit, but will have to be plumbed like any other modular fuel rail setup, including an aftermarket fuel pressure regulator. It will be a flow-thru rail setup.

Larry at Raylar suggested it won't have as that much appeal to the DIY, shadetree mechanics that want to open the hood, swap the part and close the hood. So be it. He also suggested it should have some appeal to the "hotrod crowd". All good with me.

I'll start a new thread as we get started and try and document the process as we go.

Thanks. Brad.

Update on Brads meltdown and injectors: I just flowed his injectors in past few days as they came off the boat, no cleaning, nothing and they flow close to perfect with the injector 1 off "bad" cylinder actually being a slight over achiever at 1% above the mean average. I took it a step further, left them in the machine (modern high grade ASNU) and flowed them on "inductance dwell", a warm up test for over 2 hours continuously THEN repeated the test AGAIN just on outside chance that #1 decayed hot in some way to prevent a repeat, to leave nothing overlooked and it still flows perfect.
NOW, in speaking with the OP, there's a chance fuel pressure may have dropped during the 1 minute pull that hurt this on the water AND even though it had whatever tune done to it, he has NOT held it at sustained wot alot so we may have found the leanest cylinder in a 496 and might be his tune was "on edge". I have NOT had a 496 on my dyno so I do not know which cylinder is typically the leanest and when pumping air into one with a supercharger, that sometimes changes anyways vs NA. Smittty

Good info. It seems the 496 injectors rarely have problems. When they do it's a rusted fuel rail from improper layup or a paint shedding CF module.

Even if his setup had forged pistons, it would have likely been damaged due to FP loss and lean burned cylinders.

​​​I'm assuming the OP is running the procharger fmu and not a boost referenced MAP setup?

Ryan,

Sadly, I really have no real idea. We've been running with whatever the boat was set up with before we bought it. I do know there is a boost gage and a FP gauge at the dash, and the FP increases from ~38lbs in vacuum to 50lbs+ under boost. I also have a receipt for a boost reference 2-stage FP regulator. I have to assume that's what's on the boat now. Moving forward, the work is being done by an individual that understands what needs to be done. We are going to rebuild the fuel delivery system from the tank to the intake manifold, which will include a flow-through fuel rail and a fully proportional, post-rail FP regulator, and a proper tune based on an AFR table determined post-rebuild, done by either Whipple or Boos.

While I think the ProCharger itself is a fine product, the more I'm learning about their 496 kit, the less I like it. They just didn't address many factors as they should have. We are going to correct those

Thanks. Brad.

Pretty much true of all their kits throughout their history, unfortunately.
They just love fmu’s :(

Smitty,

Thanks for the info. As welcome the news that I don't need new injectors is, this was bittersweet to find out. We all like to find a definitive smoking gun. At this point, we may never know for sure exactly what led to this. It may well have been the advanced timing of the stage 2 Whipple tune, coupled with a less-than-ideal fuel map from the ECM, all working against the demonstrably inferior OEM cast pistons. The one thing I DO know is that we are going to address all these factors as we put the engine back together.

Thanks. Brad.

SB,

FMU.... Fuel Metering Unit?

Thanks. Brad.

Fuel Management Unit.
What you are calling a ‘boost reference 2-stage FP regulator.’