I can brick a GM ECU for not pulling the radio fuse when writing a tune back or not having a charger on it.
Carry on...

What does that mean ? Turn it into a useless brick ?

You`re really fighting this instruction hard ! lol
It doesnt but if there is a spike the battery will absorb it.. interference is also issue , going straight to battery helps with that too.

SB , yes . as good as a brick.

Dan,

Nope. Not anymore. I don't have to agree with the logic to follow it out of an abundance of caution. I'm going straight to the battery and making provisions to charge both batteries simultaneously.

Thanks. Brad.

jsaduwffebhuvve

Wildman,

Covfefe...? :angry-smiley-038:

Thanks. Brad.

No went to asked something and figured it out. Not able to delete comments.

Connecting directly to the battery cable wiring, you remove the potential for lower voltage feeds from poor connections (resistive) down system. Also noise as Dan mentioned. Ground wiring also important for electrical 'noise'.

The protocal is likely to ensure positive successful use and removes a factor when troubleshooting. You may have good wiring practice...others...as we've all seen, are less than desirable.

I vote to wire straight to the battery.

Tartilla,

Yup. As you can see from the diagram, I am planning to connect straight to the battery, including the ground. I just had to figure out how to charge both batteries, regardless of which battery the switch was on. Now, if I could just find an automatic, voltage sensing switch that would instantly switch to the other battery and give me a chance to get back to the trailer should the direct-connect battery take a dump. As it is right now, if the battery the ECM is connected to takes a sh!t, I'm high and dry, and I'll NEVER hear the end of it from the CFO.

Thanks. Brad.

I don`t see how a battery that goes dead takes out a ECM? Never happened to me and never been even a concern.
Worry is a misuse of the imagination, if you wanna worry, worry about something that could actually happen.
Thanx. Dan

Making this too difficult.
Use 2nd battery for back up starting only.
Make sure both batteries fully charged before boat hits the water.
The ACR is a good device, not a must, but definitely nice.

Dan,

I’m not so much worried about the battery taking the ECM out. Just the battery that is feeding the ECM going dead and me not having an ECM until I get a new battery. While this system is about as redundant as I’m going to get, I’m still going to be concerned about it until I hasn’t let me down for awhile.

Thanks. Brad.

SB,

Not really. I'm going with it as is. To my knowledge, no such automatic switch is available, so it is what it is. I’m a full advocate of a redundant battery system, and this is something short of truly redundant. I'm just a problem solver, and there is room for improvement here.

And I have to disagree here. The ACR is a must. While addressing of the fragility of the ECM, and maintaining any sort of redundancy in batteries, the ACR isn't a luxury. It's a necessity. Otherwise, you only really have one battery. What good is having a backup battery if there is no ECM to run the engine?

Thanks. Brad.

Guys,

Getting ready to dig into wiring this ACR. Seems pretty straight forward, but...

Instructions suggest 4ga wire and a 100-125A breaker/fuse for each bank. This seems nuts to me, as it's only a 10g wire coming off the alternator. Does this make sense? Or should I have had a larger wire coming off the alternator from the beginning?

Thanks. Brad.

It could at times may be needed for the starter correct? That is where the current draw is, not the charge circuit from the Alternator.

Full disclosure I did not read the spec sheet on it.

Brad , why do you hate instructions so much ??? :kiss:

This is how I did mine because I like to follow manufacturer instructions, figure they probably know best !


https://cimg7.ibsrv.net/gimg/www.off...237394c496.jpg

Wildman,

No. The two lugs of the ACR are connected to the two battery lugs of the switch and actually disconnects, disengaging the parallel circuit, while discharging (starting or running the stereo while anchored, etc.), so the starting load only goes through the center lug of the switch.

The only thing that makes sense is a scenario where one battery has been significantly depleted and draws heavily on the other battery during charging, when the parallel connection of the ACR is engaged. Outside of that, I can't see the benefit of 4ga wire when it's only a 10ga coming off the alternator. Thoughts?

Thanks. Brad.

Dan,

I'm not hating on the instruction. I will be following them. Just trying to understand the principle.

I see that you only have one breaker in the parallel circuit, when the instruction say to have one on both sides. I guess that makes sense, as the circuit only needs broken once.

Thanks. Brad.

Why make this so difficult? I have ran every boat that I have had with the battery switch in the "both" position and I have never had to be towed in because of dead batteries. I understand that a shorted battery could cause issues with doing this but the chances are small. You are way more likely to be towed in for a broken drive, overheat condition or some other mechanical failure.

Snap,

Why have the switch, then? By the time you discover a dead battery, they're both dead. I have been told by literally everybody with even the slightest opinion on the matter that you NEVER put the switch on both unless both batteries are too soft to drive the starter, and you're HOPING that the two of them combined will get you started, then you immediately switch to whichever battery you think is weaker to charge it.

Just because something else might get you first, doesn't mean you don't mitigate the risk of a relatively easily avoidable problem.

Thanks. Brad.

Where do you pull power for the stereo.

Wildman,

A breaker panel that is fed from the center lug of the switch; whichever battery the switch is set to. The ACR prevents the stereo from drawing from both batteries.

Thanks. Brad.

Someday, you're going to wish you put this much thought into adding real steering, instead of battery isolation...

MadFlavors,

Maybe. But we've been running this boat in the mid- to high 70, and the boat has yet to even hint at a desire to get out of shape. I am very careful when I run it hard. If the boat had been a handful beforehand, I'd have a different approach. If I find that it seems to have learned a new trick as we surpass prior-to WOT speeds, I'll stay out of it until the steering can be properly addressed. I fully understand the implications.

That said.... Business has been slow this whole time since we had the piston failure. This has been a good thing for getting things done, but bad for paying for the effort. The steering is still on my radar, and may yet happen before spring. But, for the moment, it's a want, not a need, as far as the checkbook is concerned. I am working out issues that don't hit like a truck in the budget area in the meantime.

Thanks. Brad.

with 1985 wires it would take 2 batteries to start a single engine in the cig. Lots of time I`d leave it on ALL most of the time. Same thing in the baja .. easy to start but I liked having both batterries while starting ... anyway that has never ever left me stranded either.
The chances of one battery taking out the other is close to 0 .. well in my case over the last 15 years anyway .
That`s the last thing I ever worried about .. the relay is a good idea thou either way
Edit: I would run a negative cable from one engine to the other also .

generally you do not run on both if you have twin engines as the two alternators can fight each other and cause issues. on a single engine with two batteries running on both is fine. if you have a concern that one battery is low you can start on the other and switch it to both and it will be fine.

All this is well and good, but not still doesn’t solve the problem of the risk of the battery the ECM is connected to taking a sh!t and leaving us dead in the water. No matter how you slice it, if THAT battery decides to fail, you’re done. Period. Even with the switch set to “ALL”, the failed battery will drain the other in short order and there you’ll be, needing a tow. The ACR solves the problem of charging both batteries regardless of which one the switch is set to, which is great. But setting the switch to all solves nothing, and only invites an additional problem. I have personally witnessed the phenomenon of a failed battery draining a good battery. Took about fifteen minutes with the engine running, and the alternator was so hot you could hardly even look at it.

I’m going to call BlueSea and make a suggestion for a new product. I doubt it will get us anywhere, but a phone call is free, and they are probably the only people that would be interested in developing such a product.

In the meantime, I am working on finalizing the electrical in the engine well with the best configuration the market has to offer.

Thanks. Brad.

Guys,

On other fronts…. Heads are done. Block is done at the machine shop. Cam is on order. Mods to intake manifold is all but complete. Fuel and oil line fittings and hose are in. Moving forward.

Interestingly, the builder happens to mention that there were no valve seals on the valve stems when he disassembled the heads. And we weren’t burning any perceivable amount of oil. We were losing a bit over time, but I attributed that to the PCV being part of the intake manifold, and the ProCharger pushing oil out the dipstick. Weird, right?

Thanks. Brad.

I dont put valve seal springs on the exhaust.. I thought some guys leave em off all together , More lubrication.

Dan,

Not in my wheelhouse. I know what you’re saying, but the builder didn’t specify. He said, “No valve seals”.

https://cimg1.ibsrv.net/gimg/www.off...62ed88dbc.jpeg

Thanks. Brad.

There's a few types of valve seals. I've used the hat style on the exhaust vs a fixed on the guide boss positive seal.

The hats seem to allow lube but also reduce it from a full exposure.

Exh guides don't have the vacuum draw through energy like the intakes do.

Brad, what is the amperage of your alternator?

A 10ga wire will support 30amps 100% duty. Length of wire also plays a factor.

It's bizarre that he has not seen that on a performance marine engine. Sometimes you will see a puff of smoke on start up dependent on oil viscosity and duration between usage. I've run with no seals before. I currently do not know how my heads are setup, I believe like Dans.

Tartilla,

OEM Merc alternator, rated at 70A. I had it checked a week or so ago. It was putting out 87A. Initially, I assumed that was a good thing, and the tech at the shop, who do nothing but starters and alternators, didn't indicate a problem, but is that a sign that something is amiss? A faulty regulator or something? Again.... Not my wheelhouse. The only alternators I've ever replaced have been automotive, and when the bearings scattered and the alternator had seized up. I'd much rather address any potential issue while the work is easy.

Thanks. Brad.

Rookie,

Marine engines are about all he does, and mine is very likely the most vanilla engine he's ever done. He didn't specify if it was just intake valve seals he was expecting to see and didn't, or all of them. I do know I don't recall seeing any smoke or smelling burning oil at start up or any other time. We did have some oil loss, as I've mentioned, but minimal, and, after learning about the PCV situation with the 496, I attributed it to a boost issue forcing oil up the dipstick tube.

I have total confidence in the builder, as he comes very well recommended. I'm sure the heads will be set up properly for our application, including valve springs.

Thanks. Brad.

Who is the builder is he local to you?

Wildman,

I don't think he wants his name dropped. He doesn't build engines for a living. He's a service manager at a local car dealership, and does engines on the side because he enjoys it, but doesn't want his phone ringing off the hook. I've looked for him online and all I can come up with are his connections to the dealership. He's been building and wrenching on engines for 50yrs. His personal ride is a 26' HTM with a, 8-71 540 (I think) that will bury the GPS at 120. I've seen several of the other engines he's done, and... WOW. Particularly the 14-71 588 and the twin turbo 540, both in mid-20'ish tunnel death traps. The hardest part of dealing with him is keeping him on a leash. He likes to throw recommendations at me, and I keep having to remind him that we still have the stock Bravo One drive.

I was originally going to go with a guy that goes by "Skinny" in Somerset, KY (RPM Motorsports), a 3hr drive away, but an OSO member turned me onto this local-to-me builder that is more into high performance marine engines, rather than just marine repair. The local part also had some considerable appeal, as I can take a 20min drive and gawk at our progress whenever I want, which he welcomes.

Thanks. Brad.

The 496s came from the factory with valve stem seals (16). Your builder has built several 496s up with superchargers etc so he knows what a factory untouched stock 496 should have. Very strange indeed.

That's kind of a soft spring, but I don't recall cam specs. I think OEM cam is very mild and easy on valvetrain components.