sdthoren

Robert, I'll see if I can put my excel spreadsheet into words... If you want to get speed in miles per hour, MPH; 1. start with this: rpm (revs per minute) * 60 (minutes per hour) gives engine revolutions per hour 2. then this: tire diameter (inches) *3.14159 => this gives the tire circumference 3. divide the tire circumference by: 12 (inches per foot) * 5280 (feet per mile) => gives the tire circumference in miles instead of inches! 4. now multiply the transmission ratio by the differential ratio (engine rev / driveline rev * driveline rev / wheel rev) multiply items 1 and 2 together, then divide by items 3 & 4; For your truck, this becomes: MPH=(2100rpm*60)*(43.1*3.14159) / (12*5280*5.77*0.85) = 55mph. Not your 60mph quite cruising speed, but pretty respectable. I know I don't want to hit 70mph in my old dumptruck! Just for grins, I looked at gearing and torque. Assuming an ENDT673 puts out 600 ft-lbs, your low end gearing of 18.96, your tire size (I assumed 43.1"), and good traction, you can put 6334 pounds of force to the ground! That's almost 800 pounds of force per tire from 1422ft-lbs of torque applied to each tire! OK, enough is enough, the geek engineer in me is starting to come out! Hope you have fun with your truck! Scott

Squid, I have a single axle dump truck with a Thermodyne that weighs 14,200#. These trucks are made heavy duty, and they are heavy, even if they are a "light" model with lots of aluminum. I would say you are safe assuming 12,000 to 14,000 pounds for a tandem tractor. Scott

Justin, I was researching starters/alternators & thought of your post. Here's a couple of websites that may be of general help and good reference: http://www.prestolite.com/pgs_training/training_0.php - Prestolite (Leece Neville) electrical manual http://www.hss.energy.gov/NuclearSafety/te...d/standard.html - There are a bunch of manuals here. Some of the electrical fundamental handbooks deal with DC circuits, but mainly AC circuits. Hope this helps, Scott

Glenn, Those pictures are of the B615 I saw on eBay. It looks like the air cleaner has been removed; I can see a little bit of the cowl fitting... My B613 has the tin cover over the radiator. Fifth wheel, that's a good catch, I had never paid attention to cab height. I guess with the dropped floor on the B70 series cabs, you would need to raise it up. So the fender extensions do provide a vertical adjustment for the rear bolt pattern of the fenders. Now I gotta go look! Scott

Hi Glenn, My B613 has the standard radiator, not the wide one like my B70's. Now that you mention it, it seems HarryB has a B615 and the photos he sent shows the wide radiator. Harry indicates that most of the B615's were sent to Australia, but I did see one on eBay that the guy thought it had a detroit in it (it may have been a V8 Mack). I'll attach a couple of photos of the eBay truck, but they aren't the greatest for size/resolution.

Cayoterun, The B73, B75 & B77 series trucks have a longer hood and include fender extensions to allow installation of a cummins inline 6 engine, which is several inches longer than a 673. The hood will be too long and have a cut out for the air intake. The B61 air intake enters the front portion of the cab before entering the engine compartment. The air intake for the engine on a B7x series enters directly into the engine comparment. All that being said, if you have a complete B61 (with damaged fenders, radiator, etc), the radiator, headlight panels and fenders from a B7x series should bolt directly onto your B61. I haven't measured the bolt spacing at the bottom of a B61 radiator vs. a B7x series, but they look pretty close. As mentioned previously, you would need the B61 hood. I haven't verified the fender bolt pattern either, but would be very surprised if there was a difference. I'm assuming you have everything for the B61 and have access to a B75 front clip. The B75 cab mounts to the frame a little farther back, the rear spring hangers for the front axle are different (on a B61 the front cab mounts are part of the hanger, where on a a B75 they are separate; at least on mine), and the access panels between the fender and hood are different (probably need to use the B61's). Let me or HarryB if you have questions - I've got a B613, and several B7x series trucks; Harry B is modifying a B6x series to fit a large bore inline 6. We've been working the issue from a different angle, but could probably help you out if you decide to jump in! Scott

Paul, I was able to find a couple of wheel studs for my '58 B613 at NAPA. They were a special order, but just measure one up with a caliper so you have accurate numbers for length, etc. Then take one in when you go. They should have a set of books available to look at & compare with your sample. I will see if I still have the receipt for mine when I get back in the shop tomorrow & get you the part numbers. Scott