doubleclutchinweasel

This was a R-model schematic. Note the Stop Light Switch and Double Check Valve near the treadle valve. Not sure if this is the same on your newer unti, but it might give you some ideas

There is usually a check valve or a double check valve right there. Attached is some double check info. I don't care much for the push-lock fittings, personally. YRMV. The "plastic" compression stuff is probably DOT air line tubing and fittings. Really good stuff. DC Valves.pdf

You know, now that I think about it, I THINK I jacked up one wheel on a tandem Mack once, put it in gear, and that one tire spun free without trying to move. That truck did NOT have the air locker. So...maybe? Maybe there were full open models? But, I cannot answer that part of the question with 100% confidence. Interesting question, though.

I'll take your word on the Lanova RPM range! I'm just saying that Mack referred to the 673 as a "high speed Thermodyne". Might mean about as much as the "wide track Pontiac" from the '60's...which had the same track width as its Chevy or Olds cousins! LOL!

Biggest snag I remember (US cabs here) was that the "short" pre-'73 used a different type of front cab mount than what you see in the picture. That one is the later "pivot" mount. The older ones had a flat mount with a round rubber biscuit between the cab and mount.

I've been following this one for a while, but have said nothing. It has been fun watching the comments on here. Like on so many of these, there is more discussion happening than just what relates to the original question. Guess that's why I like it here so much! When Mack brought out the "673" series Thermodyne (still 672 cu in), they made a point of differentiating it from the earlier Lanova engines by referring to it as a "high speed" engine. I am guessing the piston, head, and fuel delivery were system were the primary reason for the higher RPM range. In fact, I think Lanova was the name of the combustion chamber design patent those earlier engines used. Really like re-living the old Maxidyne/Maxitorque era! I remember when those first started showing up. Personally, I never got used to the 5- and 6-speed transmissions. Just hated the RPM drop between gears. Too much time behind a Quadruplex, I guess! But, the Maxi engines were definitely revolutionary for their time. Still cool to read the old brochures. Takes me back to when I read them for the first time. That whole Idea of "high torque rise" and "constant HP" was so different from anything else out there. Somebody mentioned earlier about Mack having engineering power back then. Yes! I am an engineer myself now, and can really appreciate what Mack did then, taking a step out of line and doing something so different. Took guts. And, as somebody else already mentioned, I think constantly tightening emission regulations were the downfall of the Maxi setup. Easier to run clean if the engine stays in a more-or-less constant RPM range. Same thing is still happening today, with cars and pickups getting more and more gears. The most efficient, and least polluting engine is one that runs at a constant RPM, right in the "sweet spot". Anyway, just thought I would chime in here with my 2 cents! Hope everybody had a great Christmas and a happy new year.

Yes, R611 was ENDT-673C, 250 HP, and would have had the tall air cleaner. Fuller transmissions were definitely an option, too.

I see them now. I was looking in the wrong lot. That makes my sticker peck up!

Holy smoke! Can you show the long. and lat. on that maps shot?

Clipped this from an Etnyre history lesson...

Incidentally, I believe the "standard" you are trying to achieve is 1,000 revolutions of the cable per mile. For what that's worth!

Holy crap!

There are several folks out there who might be able to help... https://www.texasindustrialelectric.com/800_Series_Speedometer_Adapter.asp https://speedometercablesusa.com/gear_box_adapters.html https://recordtechnologies.com/products/ratio-adapter https://www.bobsspeedometer.com/products/ratio-adapters/ https://www.dicksspeedotach.com/speedometer-adapters/

Ran a bunch of R-models with 250-horse ENDT-673C engines and 18-speed Quadruplexes. Were very good, reliable trucks. Real slugs compared to what they have today. But, pretty good for the day. 170-horse B-models we had were tough, but slow.

Both appear to be overdrive models ("X" and "O"), at least. Does the RTLO still have the "reversed" shift pattern in the 2 top gears? I know the "old" ones did. That was corrected by the "X" top plate. The RTF has the shifter moved forward (the "F"). Not sure if the other one would cause you any issues with location of the shifter. Might be possible to swap the top plate (use the "FX" version) to deal with both of those issues, but I do not know that for sure. I'll bet somebody on here will know though!

Glad to hear it!

I have not heard anything about Jack in several years.

Those brochures must be "new". By the way, I consider "new" anything past about '72!

Greetings, Ratchet. Where are you located over there?

Yip. Not for us old-timers, apparently!

Saw that one on there a while back. Lots of work went into it.

Too cool!

Guarantee if I can do it, you can do it , Mke!

Hello, Franc.

Awesome. Glad to hear you got it started. Keep us informed.