Captain Obvious

I bought fresh gas (just in case the two week old stuff had started to evaporate, thereby driving up the specific gravity) and then I took some pics of the situation. Here's my basic quick thrown together test rig. The carb lid is sitting on top of a small glass. The masking tape is just to provide a little stability to the lid so it doesn't slip off the glass: Here's and aftermarket float right out of the package. Tab looks like this: And here's what the fuel level looks like with that float. This is for the front 72 (long ear) carb, so the target is 22 mm down from the bottom of the lid. I'm way low: So I bend the float tab to adjust the level. And after a couple tries, it looks like this: The level is close, but still a little low. Big problem, however, is that I've run out of compliance. You can see in this pic that the float is so tilted that it's hitting the underside of the lid. A put a little extra pressure on the fuel inlet and it pushed past the valve and kept going: The other problem with the float being this tilted is that you can actually end up on the downhill slops side of the valve tang. So I also tried an old OEM used float and got similar results. About that only thing I can come up with is the gas is higher gravity than it was forty years ago. Fresh premium grade from the local station? Surely it can't be just me. Can it? I've done countless floats in the past. Am I just losing my mojo?

Yup. Absolutely considered it. That and/or taking material off the bottom of a floaty float. But I guess my first order of business was to try to find out if it's just me. If it's just me, maybe I need to go back to float school. I think today I'm going to try to measure the density of an old OEM float alongside a new aftermarket version. I've already weighed them (and they're the same to the resolution of my scale), but I haven't measured their volumes.

I agree 100% and I've long wanted to replace the cut-pile in my 77 with some new loop. The cut pile screams "plush" 70's to me. Makes me want to do some disco. Even though it's older, I think the loop pile looks more modern.

Hmmm. Never thought about it that way, but I guess that would be true. If you push 60 psi oil into the filter and let the other side hang open into a bucket, the bypass valve will absolutely open because the differential would be so high. So if you put a brand new high pressure oil pump on your tired worn out motor... The question is... "How much oil volume passes through the filter (per unit of time), and how much pressure does it take to achieve that?" Or turning the question around... "How much oil volume can you push through while keeping the bypass valve closed?" Fram's PH8A says the bypass valve opens at 12psi differential. How much oil could you push through the filter at 11 psi differential? Enough for even a worn out motor? Anyone know what the spec is on the pressed-into-the-block bypass valve is? For all I know, it's lower than the ones built into the filters? I took a quick look at at couple FSMs and didn't find any spec. They talked about it, but no pressure spec.

That's why I posted that media bias chart earlier. There needs to be news. But get your news from the top tier news organizations. Not facebook or some guy posting memes on the internet.

Well maybe it's extra floaty aftermarket floats or something. I'll post a pic of what I got going on when I get a chance. The problem I'm having is that the level is too low. So I bend the tab down some. Level comes up some, but not enough. And then when I keep bending the tab down, I eventually run into the situation where the float mechanically bumps into something (underside of the lid or inside of the bowl chamber) before the valve closes, and it overflows. Basically, I can't bend the tab down far enough to bring the level up to spec before I run out of compliance. It's like the float is too floaty. I got tired of messing with it before and went ahead and bough all new parts... New aftermarket valves. New aftermarket floats. I was hoping it would all magically come together with the new parts, but no joy. I've got some antique OEM (not aftermarket) floats here... Maybe I'll see how they float.

Arrgh... Stupid floats!! These things are working me over! I'm finding it difficult to get the fuel level high enough. Is it conceivable to think that maybe today's gasoline has a higher specific gravity than the gas they were using forty years ago? Heavier gas makes the floats more buoyant and that drops the fuel level? Maybe some sort of EPA thing to slow down evaporation? Or am I just losing my touch?

Well first of all, let me be clear that I'm no lubrication expert, but now that I've got a couple more minutes, let me try to explain a little bit. First of all, I think the premise that both the static and dynamic pressure are involved is incorrect. Since the bypass valve is around just the filter media, the static pressure should have no effect at all. The only pressure that should matter is the differential pressure across the filter media. Any static pressure should come out immediately in the math. Second, I would claim that the differential pressure across the filter media (assuming that media is clean) is not high enough to open the bypass valve. You might say "But what about a cold engine just started then... The cold thick oil would be harder to push through the filter media thereby creating a higher differential pressure across that media". And to that, I would say "Yes, but don't forget that cold thick oil would also be harder to push through all the bearing clearances and oil passageways, which would increase the pressure on the clean (outlet) side of the filter, thereby keeping the differential about the same." As evidence, I would cite the oil pressure gauge. It's on the outlet clean of the oil filter. It's higher when the engine is cold and the oil is thick. And the higher the outlet side, the lower the differential pressure across the media. And on the inlet side... the pressure into the filter is limited at the top end by the pressure relief valve inside the oil pump. That's my non-expert take.

I disagree with both your premise(s) and your conclusion(s). How far from the original thread do we want to go? Haha!

Cool, and thanks for the confirmation. One question though. When you said the fuel pump comes off in start... What you really meant was that the fuel pump comes ON in start, right?

The Black Box? So that's what they call that one. Been many moons, but faded brain cells support that moniker. Didn't know that about the layoff-rehire culture. Probably due to the contract style of relationship with their customers. Not very disappointed that I missed out on that.

LOL. Yeah, what science fiction was that one? Resident Evil? Did I get the right one? Big corporation builds virus in an attempt to create a super-soldier. Doesn't work right and escapes from the lab and animates dead tissue. That's the one, right?

Well I was thinking that things that fly are aviation. But I'm not in the business, so I don't know the finer points. However.... I almost WAS in the business. Recruited out of college and flown out there for a "mass" interview where a gaggle of soon-to-be graduation students are all brought out at the same time and stuffed into a meeting room. In that room, they are forced to watch boring corporate videos (on VHS) and have ridiculous question and answer sessions before being led one a glamorous plant tour by some woman from personnel to show them where they could be working. When it came for the plant tour, two guys from some other department came looking for me... "Mr. Obvious, can you come with us please?" They took me out of the gaggle and led me to another small meeting room where they interviewed me for about an hour asking all sorts of stuff... When I asked a couple questions about what I would be doing, they pointed out the meeting room window to a different building which had all the windows covered up. They said they couldn't tell me anything at all about what I would be doing, or what I would be working on, but they assured me that it would be great work. I never got the plant tour. I have no idea why they singled me out, and I didn't take the job, so I have no idea what it was. Clearly military. B-2 maybe? Almost took it, but didn't. So we were almost work-mates. You, me and the other 45000?

LOL. Yeah, it kinda makes me wonder a little too. There have been people who have "constructed" a fuel injection relay out of two independent generic relays. I wonder if those people included those additional components.

Yes, I believe with a power source and some crafty meter work, one could determine if those extra components are included with the Bosch unit. I suspect they are. Oh, and by the way... There are two diodes inside the assy (not just one), so I edited my post above. Hmmm... I'd have to look into that, but I bet the ramifications are unpleasant. Probably not "light the car on fire" unpleasant, but maybe "fuel pump runs when it shouldn't" kind of unpleasant. If you want me to dig into it, let me know.

Exhaust leaks can make a ticking sound. And the injectors are supposed to click. So between all that and the solid lifters going clickety-click, I can't tell if the noises on the video are a big deal or not. I suggest look into fixing the exhaust leak(s). Rule that out and then go from there. No. On solid lifters, if they aren't making noise, you've got a problem. You may run into a situation where there is something wrong which causes the ticking to become abnormally loud, but there should always be ticking from solid lifters.

According to the documentation, there are two diodes and resistor inside the original fuel injection relay. For me, the question is "Does that Bosch relay have those three two additional internal components?"

Because (as mentioned above), 95% is not 100%. Since your in the flight business... If 100 flights were to come into your local airport and 95% of them landed safely. And, of course, one other possibility is that it's a mutation variant that is able to slip through the existing vaccine. That's why even if you don't think you need it for yourself, do it for all the other people you come into contact with. We're all in this together and if you don't get vaccinated, you're potentially the Petri dish for the virus to mutate. If you want to get back to normal, get your vaccine!!

Here's a couple threads with info on compressing the bumper shocks: https://www.classiczcars.com/forums/topic/55336-collapsing-shocks-to-push-bumpers-closer-to-body/ https://www.classiczcars.com/forums/topic/64753-depressing-early-260z-bumper-struts/

Wait... Are you asking if I've done something just like that? https://www.youtube.com/watch?v=VomBuudIDsM

Won't work. You'll be able to calculus the living crap out of it, but the car just doesn't respond to Fourier transforms, Laplace Transforms, OR diffy Q.

My Gerstner. It's absolutely the centerpiece of my workbench. I got it a number of years ago from a retired machinist who used it for decades at his work. When he was showing it to me, he was pointing out blemishes and little scars and telling me that it would be pretty easy to strip it and refinish it. I asked him why would I spend time taking out all the history and personality that he so lovingly put into it? He beamed.

Close enough. 78 FSM says .20 intake, and .25 exhaust. Both cold. The interesting thing (for me) would be to try to figure out why yours are adjusted so tight. Was it a mistake by the last person who was in there, or has something moved and closed up the gap over the last bunch of miles? Unless the adjuster lock nuts are loose or something, it'll probably be impossible to determine, but I'd spend some small amount of time trying.

Make sure you put the flare nut on before you flare the tubing.

Make sure you put the flare nut on before you flare the tubing.