joe440
Well-known member
drive shaft angle shouldnt be too bad. the motor will sit high and be about dead straight with the rear.
36 ford pickup w/ cummins
- Thread starter joe440
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Snake Farm
Ol school snake charmer!
Sounds like the driveshaft tunnel will make a great armrest!
This is gonna be one awesome truck!! [cl[cl[P[P[P
Torch
Extremely dangerous with a torch!!!
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the rear axle can sit higher than the transmission as long as you run the same pinion inclination angle on both.., and the engine is in line 90 degrees to the axle looking down from the top.
Your going to need something to control axle wrap from all that torque.
If your tranny and axle line up perfectly, the u-joint will never rotate in it's bearings and the bearings will flat spot.
The factory designs the driveline out of line to cycle the bearings in the u-joints
when a driveshaft angles and power is transmitted through a u-joint, each cup rotates through a different orbit of the drive shafts center. this orbit isn't a feature of the u-joint but is a feature of the driveshaft angles and where in relation to that angle a u-joint cup is to the center of the driveshafts.
The cups travel in a circular orbit of drive center if the shafts are lined up but in elliptical orbits if the shafts are at an angle.
This causes a difference in the rotational speed of one shaft compared to the other.
The driving shaft splined to the engine isn't going to speed up or slow down so it is the next driveshaft past the u-joint that will.
It speeds up for 90 degrees then slows down for 90 degrees.
The second driveshaft speeds up and slows down 2 oscillations (vibrations) for every one revolution of the driving shaft.
Now that drive shaft had to be hooked to an axle... and you don't want your axle speeding up and slowing down. it needs to run steady.
By ingeniously phasing the front and rear u-joints on either end of a driveshaft you cancel out these oscillations.
The driving shaft still speeds up and slows down the middle shaft but the way the middle shaft speeds up and slows down the axle is set or phased opposite that of the front so the engine and axle see steady rotation while the drive shaft between them is oscillating.
getting the angles wrong causes this oscillation to get out of the driveshaft and into the axle where you can feel it. One end of the driveshaft now fights the other and you start to eat up u-joints.
You don't feel the oscillation in the middle driveshaft any more than you would feel anything if you put your car on jacks, pulled the rims and revved the engine up and down with the tranny in gear.
This oscillation is invisible to your senses, you only feel the interference of the angles not being phased, and imbalance if the drive tube needs a weight.
Don't believe me?
I used to know the math and geometry to prove it on paper but have since forgotten it..
Constant velocity joints... run all the driveshafts at a constant velocity without this oscillation
A vehicle with one driveshaft is a 3 shaft u-joint system with 2 shafts having constant velocity and one between oscillating.
A Double Cardan constant velocity joint is also a 3 shaft system contained in a space about 8" long.
It isolates the oscillations in the smallest possible space and in a part with the smallest possible mass..the center yoke of the DC cv joint.
The Double Cardan CV Joint eliminates the need for shafts to line up while maintaining employment of U-joints.
The ball and yoke CV joints in modern cars completely eliminate u-joints and eliminate any requirement for the shafts to line up.
Your going to need something to control axle wrap from all that torque.
If your tranny and axle line up perfectly, the u-joint will never rotate in it's bearings and the bearings will flat spot.
The factory designs the driveline out of line to cycle the bearings in the u-joints
when a driveshaft angles and power is transmitted through a u-joint, each cup rotates through a different orbit of the drive shafts center. this orbit isn't a feature of the u-joint but is a feature of the driveshaft angles and where in relation to that angle a u-joint cup is to the center of the driveshafts.
The cups travel in a circular orbit of drive center if the shafts are lined up but in elliptical orbits if the shafts are at an angle.
This causes a difference in the rotational speed of one shaft compared to the other.
The driving shaft splined to the engine isn't going to speed up or slow down so it is the next driveshaft past the u-joint that will.
It speeds up for 90 degrees then slows down for 90 degrees.
The second driveshaft speeds up and slows down 2 oscillations (vibrations) for every one revolution of the driving shaft.
Now that drive shaft had to be hooked to an axle... and you don't want your axle speeding up and slowing down. it needs to run steady.
By ingeniously phasing the front and rear u-joints on either end of a driveshaft you cancel out these oscillations.
The driving shaft still speeds up and slows down the middle shaft but the way the middle shaft speeds up and slows down the axle is set or phased opposite that of the front so the engine and axle see steady rotation while the drive shaft between them is oscillating.
getting the angles wrong causes this oscillation to get out of the driveshaft and into the axle where you can feel it. One end of the driveshaft now fights the other and you start to eat up u-joints.
You don't feel the oscillation in the middle driveshaft any more than you would feel anything if you put your car on jacks, pulled the rims and revved the engine up and down with the tranny in gear.
This oscillation is invisible to your senses, you only feel the interference of the angles not being phased, and imbalance if the drive tube needs a weight.
Don't believe me?
I used to know the math and geometry to prove it on paper but have since forgotten it..
Constant velocity joints... run all the driveshafts at a constant velocity without this oscillation
A vehicle with one driveshaft is a 3 shaft u-joint system with 2 shafts having constant velocity and one between oscillating.
A Double Cardan constant velocity joint is also a 3 shaft system contained in a space about 8" long.
It isolates the oscillations in the smallest possible space and in a part with the smallest possible mass..the center yoke of the DC cv joint.
The Double Cardan CV Joint eliminates the need for shafts to line up while maintaining employment of U-joints.
The ball and yoke CV joints in modern cars completely eliminate u-joints and eliminate any requirement for the shafts to line up.
Last edited:
Torch
Extremely dangerous with a torch!!!
- Joined
- Jul 18, 2008
- Messages
- 1,630
I don't think anything has enlightened and taught the common man engineering physics and science more effectively and honestly than the car.
and nothing has freed him from physical burden and locality as much as the car
Simply the single most important advancement in humanity since the mastery of fire
and nothing has freed him from physical burden and locality as much as the car
Simply the single most important advancement in humanity since the mastery of fire
joe440
Well-known member
^ thanks for all that, definitely will remember that when the time comes to set it up.
got the rear welded up today
got the rear welded up today
thanks for the front end pics, i never knew that a transverse leaf was used on the larger chassis trucks like that, my project started with a 1952 gmc 1.5 ton chassis and it had common parallel leafs on it
and that diff, what is it from, that thing has some monster outters on it eh!?
what front axle are you gonna run and how are you gonna suspend it?
killer build, im in the midst of doing up my frame too, check it out under builds.. "new project what is it?" if ya wanna [
and that diff, what is it from, that thing has some monster outters on it eh!?
what front axle are you gonna run and how are you gonna suspend it?
killer build, im in the midst of doing up my frame too, check it out under builds.. "new project what is it?" if ya wanna [
joe440
Well-known member
thanks, the rear end is out of an 02 F350 and i bought the dually 10 lug adapters which were pretty expensive but i needed to get them haha. the front end is a the speedway 4" drop axle kit with ford spindles and their ford front disc brake kit.
jawman
Well-known member
defiantly going to watch this one. cummins and rat rod in the same sentence, it is like a dream come true. I have seen a 6bt cummins like yours in a model A sedan in Hot Rod mag and I have been thinking about it ever sense. later on down the road get on the Dodge cummins forum and learn how to make that engine really work for you just by turning a few screws on your injector pump.
ANNAMEL
Well-known member
Nice build. I really like what ya got so far. Keep it up.
lvin4jc
Well-known member
Check out the latest "Old Skool Rodz" magazine, there's a sweet rat sedan with a 6bt 12 valve.
joe440
Well-known member
its a rolling chasis! wheelbase 146"
skull
''SARCASM: just one of his many talents.''
146''
146''
''give me 40 acres and l'll turn this rig around''
Later
146''
''give me 40 acres and l'll turn this rig around''
Later
jawman
Well-known member
I think you are talking about the welderup rat rod. they have a web site with a few other rigs including a Diamond T flat bed with a 6bt 12 valve
lvin4jc
Well-known member
Yeah I think that's the one, it's up in Billings (back by home for me).
jawman
Well-known member
you can google it and find all kinds of info, pictures, and videos
joe440
Well-known member
all welded up and on the ground
Snake Farm
Ol school snake charmer!
Neat and tidy! Nice work[cl[cl
joe440
Well-known member
got the motor mounts made. Under estimated the weight of this monster, but it came up when i put the new tires and rims on (the ones in the pics). Probably going to add another leaf to the front spring to help a little. Next up is trans mount and fit the cab.
lvin4jc
Well-known member
Lookin' good man, you're smokin' this thing, do you have a job or do you work on this 24/7? You're making me feel bad about my truck, lol.
