doubleclutchinweasel

The brain trust on here just got a lot bigger...

It's possible that bolt may have been replaced with a softer bolt at some time (like an 8.8). That could explain why it broke and the others did not. I think you're gonna be okay.

Just an FYI on 6V starters running on 12V... Used to build dune buggies out of VW Beetles. Sometimes ended up with a combination of parts that left us with a 12V system running a 6V starter. Never recall seeing a 6V starter fail from running on 12V. Ever.

We gotta see this!

I love this thread! You are exemplifying one of my core philosophies. "Not knowing you can't do something is sometimes your greatest tool." You remind me of how it was when I grew up. We didn't have the internet or forums. Hell, we were lucky if we had any type of manual to look at. But, that never stopped us from taking things apart, figuring them out, and putting them back together. You just have to pay attention to what is going on, make mental notes, learn from the things that didn't go exactly as planned, and keep on keepin'-on. With your abilities, creativity, and attitude, and a little guidance from the pros on here, you'll be hauling s#!t again in no time! Keep up the great work!

Well, there you go!

This one seems to fit... "If you jack up one side of your above-ground pool to create a "deep end"..."

Argh-argh-argh! Binford 4000 diesel...

Yeah. I know Hancock got caught up in “the purge”. I miss him though.

Right. That's the Jim (Hancock) I was hoping would come back...because he had so may great pictures.

No, I'd bet you are right on the money on that one. Ah, the good old "innocent" days!

Yeah, spinning an old driveshaft at modern speeds can be a disaster waiting to happen. Do you suppose they never planned on those old trucks going that fast? Or do you think the numbers were less conservative back then? Or do you think they just had no clue?

It is the RPM where the rotating device reaches a natural harmonic frequency and starts to oscillate. This can cause vibration or the shaft can actually flex and bend.

I have worked a good bit with balancing machines in use on some of our products in the past. The balancer manufacturers mentioned that half true critical speed. They said the same thing...you can pass through it, but don't hang out in that neighborhood. I've heard that Francis wheel turbines in hydro plants experience a vibration at some RPM while ramping up and ramping down, and that is probably that same phenomenon.

I find studies about driveshaft critical speed dating back to the 1960's. Not sure when they started thinking in those terms. Every rotating device has a critical speed, though. That is a fairly fundamental engineering principle that gets applied to most anything that rotates. So, it IS kinda weird that those left the factory that way, isn't it? I'd be curious to hear what you, or someone else, figures out about this.

Excellent point, Geoff.

Yeah, sounds like a different "Jim". They're all welcome anyway!

I see lots of Cummins gen sets painted that color. But that was a new one on me. Sure was a honkin' big mother. There's some smaller motor on the trailer behind it, but I didn't get a good shot of it.

It sounds like a blockage or a bad check valve from the description. I mean, if you can't even hand pump fuel through it, there has to be something blocking the path. And I'm not familiar enough with the internals to tell you what to do or not do. But there are others on here who probably know that pump inside-out.

I was thinkin' the one I was talkin' about was in New Hampshire. Hancock?

Is "Tundra" the Jim I'm thinkin' about?

I sure wish somebody could convince Jim to come back. I sure miss his pictures! If it wasn't for Other Dog, I would be in serious withdrawal right about now!

Correct me if I'm wrong, but the hand pump should not pump up and get "tight". It should move fuel even after it is primed. The fact that no fuel is going out the return line suggests that either the return passage is plugged or the inlet is plugged. Sounds very much like an inlet line is completely stopped-up. Any chance the check valves could be installed wrong or frozen up? Can you blow air through the inlet line to the tank and through the return line to the tank? Can you pull fuel from the inlet line with a hand-held vacuum pump? Or, I could be on drugs...again.

Yeah, that qualifies.

That matches what I said above about changing polarity of EITHER the armature or the field to make it run backward. As long as the armature and field windings are not disturbed, the polarity going to BOTH of them is reversed, and the motor would turn the same way. Very good the way you stated it. Makes everything sort of come together! Thanks for that post!