Well I just want you to be prepared ...
Holley is definitely not plug and play or "easily" made to work.
I don`t see anything that can be reused wiring or harness wise on a 496 to work with Holley. Maybe some sensors but you`d have to know what voltage/ohms they are and set up tables. That entire wiring harness will have to go.
Then you`ll need a tune from scratch..
Took me a whole summer to wire up my last engines
If you`re doing the wiring I suggest blowing up the shematics , makes life easier .

CTS , coolant sensor set up if not one in the drop down
https://cimg7.ibsrv.net/gimg/www.off...d9d8cb4ad0.jpg
https://cimg8.ibsrv.net/gimg/www.off...5128a492ed.jpg



https://cimg0.ibsrv.net/gimg/www.off...db8018b780.jpg

Dan,

I'll definitely hang on to those. Not sure if there's a difference, but we are using the HP unit. Supposedly, it's got assignable inputs for everything. We'll see. I'm also getting the harness along with the ECM.

The builder says he's got this. It's definitely not in my wheelhouse. I'm not letting go of my PCM555 until we get it all rolling. If it doesn't work out, I'll send the 555 off to Boos and live with it.

Thanks. Brad.

https://cimg4.ibsrv.net/gimg/www.off...4a2387d06.jpeg
https://cimg7.ibsrv.net/gimg/www.off...6baf7903a.jpeg
https://cimg9.ibsrv.net/gimg/www.off...3c0afe21d.jpeg
https://cimg1.ibsrv.net/gimg/www.off...c1c02d661.jpeg
https://cimg2.ibsrv.net/gimg/www.off...365f5ba1e.jpeg
https://cimg3.ibsrv.net/gimg/www.off...db6385042.jpeg
https://cimg4.ibsrv.net/gimg/www.off...07d763815.jpeg
https://cimg5.ibsrv.net/gimg/www.off...a7c9eedce.jpeg

Looks like we’re off to the races.

Thanks. Brad.

Plenty of room to work on the cold air intake that you talked about before.

Wildman,

Yup. That's among many issues I intend to address while it's out. If we recall, the bilge pump had taken a sh!t, and was proving to be a PITA to get to, so THAT'S the first thing I'm gonna do after getting the bilge cleaned up. The charging seemed to be dropping off the same weekend of the piston failure (projecting some really weird electrical anomalies that were indicative of a dying battery/alternator), so I'll at least be getting the alternator tested; most likely replace it. The batteries are both good, according to the charger. Also gonna try and convince the CFO the SilentChoice was a significant contributor to the failure and ditch it while it is out. If I can, I'll be making some riser/angle blocks for the exhaust risers, as well as modifying/extending the riser tips, which will significantly reduce the potential for reversion. This will open up some cam options. The ProCharger crank pulley was another hangup getting the engine out, along with the long output snout on the drive end, but I don't know if there's anything we can do about it. Getting rid of the wye-pipe for the SilentChoice will go a long way to making it easier to shoehorn back in. It was a serious thorn in our side getting it out. It's a REALLY tight fit in there.

Thanks. Brad.

LOL I have twins in a 32, I know.:drink:

https://cimg1.ibsrv.net/gimg/www.off...48c126e0d.jpeg

Wildman,

https://cimg3.ibsrv.net/gimg/www.off...7813a65eb.jpeg
https://cimg5.ibsrv.net/gimg/www.off...209539786.jpeg

The Procharger crank pulley is under the lip of the rear seat and the “long” output snout was under the steering rack, as I’m sure you’re aware. Front to back, we had almost ZERO clearance. At first we thought we’d be able to rotate it to get it out. Nope. It was like trying to rotate a square inside another square. :(

Thanks. Brad.

god i love my triple for engine room work !!!

I have the same issue with my blower pulleys under the angled rear seat/front fire wall. Pretty rough access. Had to angle the engine/tranny up 45° to get it to clear without yanking the trans.

Glad you're on the path to getting it back on the water.

Tartilla,

Got a look inside today:

https://cimg9.ibsrv.net/gimg/www.off...fe9264559.jpeg
https://cimg0.ibsrv.net/gimg/www.off...f9ebf2c84.jpeg

We can clearly see where the piston was trying to pulverize the bits of piston and ring. Looks like the head gasket gave out, too. Not sure if it happened before or after the piston failure. Valves look OK.

Got the rods ordered yesterday. Gonna order the pistons in the morning and sending them to SwainTech for the top coating.

Block will hopefully go to the machine shop in the next couple days. Getting decked, both block and heads. Going .030” over on the bores.

Also looks like the SilentChoice is ditched. Anybody want it?

Thanks. Brad.

Detonation

yep... real question is
why it would happen with a stock merc engine built to run on 87... there is a cause thts needs to be found so it does not happen again in a couple hours...
of course this one is a little warmed up
but still need to find why it happened!

stock BOOSTED engine.

I have been playing with boosted engines for over 30 years. Stress level is definitely higher for me on these setups. The safe window gets smaller and smaller.

I would think fuel injector issue if it's only 1 cylinder.

I started out using fmu's. And quickly switched over to real tuning. FMU's work, but are a band aid imo. Taxing on the fuel system.

Ditched the silent choice, good move. Now the build get’s a lot more interesting.

Jeff,

The short answer is: “Stock cast pistons”. It does appear that the failed piston suffered a lean condition, but I’m not convinced that was it. The TechMate showed 16secs of guardian mode, but no codes. Personally, I think it was just cumulative detonation damage over time, due to injectors not meant for boost, and, when the piston failed, the damage escalated. Builder also suspects water in the cylinders contributed to it, but not enough to get the chocolate milk effect.

We are addressing every conceivable shortcoming of the 496 platform, including rebuilding the entire fuel delivery system from the tank to the intake, including bumping up to 60lb injectors. At the end of the build, it’s gonna be a brand new engine, built WAY more stout than OEM.

It is also possible that my practice of 50/50 mixing 93 and 89, to maintain an average of the "recommended" 91 may have been an issue. The mixing is fine, but 91 may not have been enough. We'll be running 93 from here on out.

Thanks. Brad.

UnderPSI,

As Smitty relayed above, the injectors appear to be fine. He tested the snot out of them, and they performed perfectly. I’d agree with the suggestion, but testing shows otherwise. Another possibility is that the ECM took a dump, but the TechMate isn’t showing anything out of sorts. Who knows?

As mentioned, we are ditching the FMU, replacing it with a proportional boost reference regulator, and swapping the PCM555 for a Holley HP ECM that we can tune, and bumping to 60lb injectors. We should be able to tune it pretty well perfectly from that point.

Thanks. Brad.

https://cimg5.ibsrv.net/gimg/www.off...2e3115898.jpeg
:party-smiley-048:

Those heads and pistons look real clean. Never seen that on any blower motor. No soot at all.
IMOP you tune is lean and mixing fuel octanes? common Brad,really? First you`ll never know what the final octane will be and secondly why? Trying to save a few buck? it`s a blown engine with a lean tune, you need as much octane as possible. I ad a bottle of boostane to every tank. and use 93.

Dan,

Hey.... I asked on here and got the OK.... :rolleyes: And it's not a REAL supercharger, anyway. They just call it one in the ads. :angry-smiley-038:

Seriously, though.... I was always very careful to pump equal amounts, always erring on the side of more 93 than 89. With my mild boost set up, I figured I was OK. Live and learn. Straight 93 from here on out. As much as it's gonna suck at the pump.

As far as the soot.... Trust me.... All that went to the transom. As far as I understood it, it was set up "pig-ass rich", as per at least one option I got. I think the only time it was actually lean was when we were running hard, and the boost was overpowering the OEM injectors. Gonna fix that.

Thanks. Brad.

If that's the case, octane was a BIG factor.

Most of us at times have done something similar. In the end, it never saves money. It costs more money and time.

I would go with 80lb injectors if it was me.

That`s not pig rich.. this is "pig rich"

https://cimg0.ibsrv.net/gimg/www.off...0678e59497.jpg

I would say that is oil

UnderPSI,

I haven't ordered them yet. All options are on the table. Can you have too big of injectors, to where you can't dial them down at idle? Seems a legitimate question....

I'll discuss with the builder.

Thanks. Brad.

You can have to big of an injector. I haven't found to big yet. I run 210lb injectors on my 353ci street car. I can lean it out as low as I want at any rpm.

Dan, how do the cylinder walls look? Any indication of cyl washdown and scoring etc?
​​​

There would be an optimum injector pressure/duration.

60lb injectors at 0.6 BSFC would deliver 560hp at 70% duty cycle.
​
You're turning up the Pro Charger...you would be in that 560hp area.

One of your project goals is to streamline and bulletproof the fuel system. Having a buffer on the injectors to ensure there isn't a lean scenario may be job #1.

I wouldn't think you're running at 0.6 BSFC at WOT. Maybe 0.5 or 0.55.

That's at the rated pressure of 43.5psi.

60psi running pressure you may gtg with 60lb inj with sufficient buffer.

What he said. ↑ ↑ ↑
An 80lb injector is not a large injector.

That was long ago, probably the first engine rebuild. The owner set it so rich the walls were like a mirror.

Guys,

Progress has been slow, but we are making headway.

The heads are off to the machine shop for decking.

Rods will soon be going to the crank shop for mass matching. They currently vary from 784g to 796g, according to my postal scale.

The pistons are in, have been gone over for burrs and sharp edges, and are off to SwainTech for ceramic TBC on the crowns. When we get them back, they will go to the crank shop for final balancing of the crank. I'm hoping to we finally get the engine up on the stand this evening, get the oil pan off and get a look at the crank. Fingers crossed that Merc tech was correct in telling me the build sheet indicated the forged crank.

The new 600SCI oil cooler is in.

I have been working on some exhaust riser blocks that will give us an additional ~2-1/2" elevation on the elbows and increase the slope to the tips by 7-1/2°. We are also going to extend the tips of the elbows, further distancing the water from the exhaust valves. All of this SHOULD bring the exhaust path back in line with the tips inside the transom.

I've got a list of various parts to order. Valve springs, retainers, block-off plate (transom assembly), seals, gaskets, bearings, oil pump, on and on....

https://cimg0.ibsrv.net/gimg/www.off...6cc6a9013d.jpg


Good times.... :rolleyes:

Thanks. Brad.

Tartilla,

The custom grind cam we are shooting for showed around 620HP, at 5lb boost, with 60lb/hr injectors well short of maxed out. We have not had an actual conversation about bumping to 80lb/hr injectors, though. We still might yet go that route.

Thanks. Brad.

Guys,

Finally got the oil pan off. Guess what we found….

https://cimg4.ibsrv.net/gimg/www.off...251e4ebad.jpeg
https://cimg6.ibsrv.net/gimg/www.off...82842d905.jpeg

The purple unicorn!

Thanks. Brad.

nice score

Guys,

Working on the elbow riser blocks.

https://cimg9.ibsrv.net/gimg/www.off...40ea529f5.jpeg
https://cimg0.ibsrv.net/gimg/www.off...9fcc906b8.jpeg
https://cimg1.ibsrv.net/gimg/www.off...0b7839e13.jpeg
https://cimg2.ibsrv.net/gimg/www.off...298b0c9b2.jpeg

Thanks. Brad.

Guys,


https://cimg9.ibsrv.net/gimg/www.off...87dcd058a.jpeg
https://cimg2.ibsrv.net/gimg/www.off...1f9631964.jpeg
https://cimg6.ibsrv.net/gimg/www.off...5a889d7b9.jpeg

https://cimg8.ibsrv.net/gimg/www.off...3c215fa9c.jpeg


https://cimg9.ibsrv.net/gimg/www.off...c7a7a4cea.jpeg

Ready to weld the jacket sleeve in. They will then me machined top and bottom for cleanup, then the hose connections will be welded on.

Engine is still in the process of being torn down. Heads have been decked, and the builder will begin the assembly this week, after the parts arrive. The block and crank/rods/pistons will hopefully go to the machine shop this week for boring, honing and balancing, respectively.

Most of the remaining parts should start rolling in this week. New Melling oil pump. Picked up a really nice used Weldon fuel pump, a new remote fuel filter mount.

I got the sundeck back off and stored away, but I still have yet to climb back up in the boat to get to cleaning the bilge and getting a new bilge pump in. I also need to make provisions for a solid ground strap, instead of the handful of grounds ran separately to the block, and mounting points for oil and fuel filters on the transom and battery switch on the back of the seat instead of screwed to the removable side panels.

Good times.

Thanks. Brad.

https://cimg1.ibsrv.net/gimg/www.off...7f7f28d7dc.jpg

Planning on having this water jet from 1/4" aluminum and powder coated in the same Illusion Purple the rest of the trim is in. I'm also planning to have the valve covers done the same. Possibly the intake manifold, after the builder does some internal mods to improve airflow.

Thanks. Brad.

Guys,

https://cimg2.ibsrv.net/gimg/www.off...cdd1015e5.jpeg
Before
https://cimg3.ibsrv.net/gimg/www.off...a7d5c61b3.jpeg
After. Still not done.

Got a little cleanup done this evening. Still more to go.

Discovered that someone did a REALLY sh!tty job glassing in the clearance cutout for the ProCharger. I was told by the seller we got the boat from that HE was told by the original owner’s wife (he’d passed away) that the ProCharger was a factory PQ build. After seeing this, I have my doubts. Looking at the rest of the interior glass work, there is NO way PQ would have left this this way. There is actually loose hanging FG fabric and puddles of hardened resin. I will be taking the disc sander to this, cleaning it up, and glassing it in properly.

I can also improve the wiring I did for the power to the Bazooka tube subwoofer. I didn’t like it at the time, but it was at least safely zip-tied out of trouble.

Anybody know what size socket to use to detach the wye pipe from the transom assembly. It’s a 12pt bolt head. Looks like 10mm, which is the socket I bought (I didn’t have any 12pts). I’m hoping that’s it. One of them is going to be a PITA to get to, due to the trim hydraulic lines. I’m hoping can loosen them from their hold-down straps and make some room to get the socket in there.

Thanks. Brad.

always something to improve in those bilge !
always easier while the engine is out also !!!

Spend time now in the bilge thinking about all the routine maintenance items you need to do.

Move, redesign, whatever to make it easier once the motor is back. The first time my motors were out I would sit in the engine bay and reposition stuff over and over. Also, take a very close look at ALL the wiring and rigging, no mater what its an old boat. Time to repair or replace now.

While you are at it you might as well order these:

https://a.co/d/1m8DEyh

https://a.co/d/eb2pbKr

:party-smiley-048:

Wildman,

Yup. We are going to clean up a LOT of the wiring. At least ON the engine. I don’t really have much of a problem with most of the rest of the wiring, other than the lack of a ground lug.

Literally ALL of the stuff that Merc hung on the engine, that doesn’t need to be, isn’t. The oil filter, fuel pump and filter, PS and drive oil reservoir…. All of it….. Is getting hung on the transom.

Thanks. Brad.