Gary Lewis

Delco Remy says an alternator is 55% efficient. ScienceDirect says an electric motor is between 70 & 96% efficient. So if we assume the motor is 80% efficient then converting mechanical energy to electric energy & then back to mechanical will be .55 x .80 = 44% efficient. And that, in a nutshell, is Jim's point.

Oh yes, in a post type "Chevrolet" and then click the preview button.

You do not want the shunt to see the load if you are adding things like electric cooling fans. And there's no reasonable place for you to get power for the relays after the shunt. So just tie into the starter relay's battery connection and run a fused wire to a fuse/relay unit like Jim and others have. Each individual relay can then have its own fuse and you have everything in a neat unit. But I don't understand what you mean by "But adding a second charging cable will help definitely. Its almost like halving the resistance of the shunt itself." You don't want to add a second charging cable. The big red X means to take the factory charging cable out and replace it with one directly to the starter relay.

Jeff, and anyone else that wants to try, you can see the test forum here. But in spite of what it says, and I can't figure out how to remove that text, you cannot log on with admin/admin. You can look around to your heart's content, but I don't think you can register. For some reason it isn't sending the email to confirm your registration. Still, it won't hurt to try. I used the admin function to finish my own registration for Gary Lewis, and could for you if you don't get that email. We only have this demo for another 6 days, so see what you think, please.

I thought about relay usage and its effect on alternator load. Even if the current was directly taken off the battery, wouldn't the alternator be in the "loop" and make up for that current loss. This is waay over my ability to predict, Gary, you are definitely better in electrical assessment. I try but always overlook something Assuming you power the relays directly from the battery or the starter relay, which is easier, then using relays to power high-current devices takes the load off of fuse links L & M, meaning off the cab. Yes, the alternator is still in the loop, but the only load on L or M is the miniscule pull-in current.

Wire it this way but don't add the relay nor cut the Y/LG wire on Ckt 654 unless you are installing a Rocketman voltmeter. The output of the alternator goes directly to the battery and not through the shunt. Only the load "in the cab", meaning that going through fuse link L or M which go to the ignition switch, will go through the shunt. Which means the ammeter will always show discharge. And, you should not put a cooling fan on "cab power". The wiring wasn't sized for that much load. Instead put relays out by the fan, powered directly from the battery/starter relay and use key-on power to pull them in. But, having said all that, we've had a long discussion about a better way to wire these trucks and I shipped Jeff/Big Bro 84 a harness to prove out that plan. If you want to read how that is to be done go to this thread, but let's not rehash it here.

That's the key. If the battery-charging load is taken off the shunt by moving the alternator's output to the starter relay then the shunt is only carrying whatever load is in the cab. And if you put a headlight relay harness in that part of the load goes away. Ditto the HVAC fan. But if the battery is still being charged through the shunt it is likely you'll have problems at some point. For instance, if you let the battery get really low and have to jump-start the engine the alternator is going to kick out everything it can to bring that dead battery up to 14.4V. If you have a 100A 1G in and kick the fast idle off quickly then you may get by as that alternator won't give you more than 70A until you get above idle. But Jim's 3G alternator tested at 106A at 1600 alternator RPM, which is about 550 engine RPM assuming you use the standard 460 pulley.

"And so, the point of all that is that when Anthropic says that Claude 3 can outperform GPT-4 Turbo, which is currently still widely seen as the market leader in terms of general capability and low hallucinations, one needs to take that with a grain of salt—or a dose of vibes." In other words it lies, and if you know it lies how do you trust anything it says? The young lady whose Charger we were painting over the weekend said her professor lets them use ChatGPT at university. So I asked how she used it she said she never uses any "findings" it has. Instead she asks what she might write her term paper on, or how to structure it.

Good job on the pic! The only time I use "float" is when I put two pics side by side. But that is tricky as you can't make the two pics larger than 95% of the screen size or things after the pics wind up between them. Best not to "float".

Nice instruments, Jim.

Jeff - I'm not aware of any of the forum platforms that has its own app. I'm not saying none do, but I'm not aware of any that do. Having said that, I just checked and there is an app called Xenforo but the reviews are awful and it apparently isn't working. It wasn't written by the Xenforo team, just some individual, and he's not kept it up to date - in spite of it costing $5.99. However, I've read and posted on our Xenforo test forum from my iPhone and it worked very well so I don't know that you'll need an app. On the other hand, I couldn't load pics taken with my phone's camera and discovered that I had the camera set in highest resolution mode and it was storing pictures in .dng format. I added .dng to the list of formats the forum would accept and it still didn't like anything that was in my library. So I changed my phone to HEIF format and added that to the list on the forum and now I can load up pics I take. As soon as we get a couple of things sorted I want y'all to use Xenforo and see what you think. Hopefully that will be today.

If you only dropped the pan you did less than half the job. There's another 8 - 9 quarts in the torque converter, and while you are doing it you should drain that.

Congratulations!

The 400 is a much-maligned engine, just like its little brother the 351M. But the 400 could really have been something to love - if they hadn't retarded the cam dramatically and stuck a 2bbl on it. I know a guy that put a straight-up timing set and a 4bbl on his 400 and claimed it doubled the power. So don't give up on the engine, it is quite capable if you just give it some love.

Those things almost scared the American public away from diesels with their problems.

LOL! Don't worry about it, we all have these issues. But we are in this together in this community. Basically this is an AA meeting and we all are addicts. So we don't throw stones. Anyway, glad you are getting it figured out.

We, Chris and I, are in the midst of checking out Xenforo and it is looking very promising. Having said that we've not gotten email to work nor the embedding we need, so Chris is to contact them to see how they can help us. If we get that sorted then we'll suggest some of y'all give it a spin. But you'll like the ability to edit posts, do background messaging, etc. And it looks like we can set it up so people can join w/o admin help, but will have to agree to our guidelines before doing so.

Just FYI, an '82 F250 should have come with a 400, not a 351M. The M was last used in '81 and the 351W was introduced for '82. But the 400 was retained for '82 and then replaced by the re-introduced 460 in '83.

So someone put a later sending unit in a Bullnose. That's where the MeterMatch comes in.

Check out Scott/kramtocs thread where he tested electric fans. Some draw more than others and some pull far more than others. Me, I'll stick with an engine-driven fan. Jim will probably be along to tell you why it is a bad deal to turn mechanical energy into electrical and then turn it back into mechanical, thereby having 2X the efficiency loss.

I have for a long time seen 90A alternators available for my 460 pickup on Rockauto. I always wondered if these worked fine and if they did then why 3G (shunt needs to be oversized, but any other reason why this wont work) ? https://www.rockauto.com/en/catalog/ford,1984,f-350,7.5l+460cid+v8,1126257,electrical,alternator+/+generator,2412 Would something like this work fine ? https://www.rockauto.com/en/moreinfo.php?pk=1000263&cc=1126257&pt=2412&jsn=1237 https://www.rockauto.com/en/moreinfo.php?pk=12526901&cc=1126257&pt=2412&jsn=1242 It isn't that it won't work, but that a 3G puts out 105 amps at idle. The others don't give much until 1500 engine RPM.

If my understanding is correct the stock Bullnose gauge will go full scale when 70A is conducted through the shunt, it either direction. I don't have an easy way to create that amount of current as most of my loads would be way under that, and my winch and inverter would be way over it. But if you want to run a test then figure out how to put a load like that on the system and you should see the ammeter swing.

The voltage drop is across the ammeter. Said another way, the voltage at the ammeter is the same as at the power supply. But the voltage across the shunt is exactly that across the ammeter. The wire size used to connect the ammeter to the shunt is plenty large enough to handle the ~1A of current w/o appreciable drop. As for measuring resistance, I don't own any tools that would allow measuring of that small of a resistance. Very few people do. My earlier post said the .167 ohm was 'calculated resistance". Said another way, I = E/R = .147/.88 = .167. I can't measure a shunt's resistance directly, but I can measure the current through it and the voltage drop across it and, therefore, calculate the resistance. As for the heat, fusing current determines when the conductor fails. But it doesn't determine when the insulation fails. I know that the fuse links have high-temp insulation but don't know about the shunt. But you could replace the shunt, which is exactly why I included that table on our page at Documentation/Electrical/Ammeter. All you have to do is to have a wire that drops whatever voltage your ammeter requires to take it to full scale. Ammeter #1 just needs a .167v drop, and it doesn't care if the current through the shunt is 70A or 700A. As long as it sees .167V it'll go to full scale.