[conestogaman]

The gentleman building the 4x4 Studellac is a member of our little community...

http://hotrodders.com/forum/members/utahtorque.html

I'm sure he can provide plenty of do's and don'ts on your project

[ckucia]

Conestogaman,

Thanks for the info on Darius (UtahTorque). I've come across a bunch of his posts on other forums. We seem to have been researching a lot of the same issues.

I knew he was on this board, but I couldn't remember his screen name.

Oddly, he's going with the same engine in his Studillac that I've been working towards with my project - a Cadillac 425. Its essentially the same block as the popular 472/500s, but was significantly lightened (by around 75lbs) making it lighter than an iron SBC. Torque is around 300ftlbs stock which should be about perfect for what I'm trying to pull off, assuming I can fit it in. Also, 300 ftlbs is a reasonable torque level for most manual transmissions to accomdate without scattering.

I'm trying to build a driver - once I get it together, I want it to stay together so I can actually drive it. I think I've found a combination of parts that will work well together, and won't break apart at a stoplight.

[madamstn]

JUST in case someone passes this way again. I would like to know if a sucesssful project was completed and how. Years ago you could plan on ford on the left, every body else on the right. I don't have a clue if something has become a general rule, JAG in the rear, what ever in the front. Dana 44 was a standard in jag for a number of years. Eventually they could not afford the quality control jag wanted, so they say. You could find a cast iron carrier and jag stubs for a hundred bucks. If you pass this way just something else to consider, I was looking for something else, but read this line. mark

[jwvonl]

Have you ever taken a close look at the HMMWV. In order to accomplish a complex drive line the originators of this vehicle. ( I think it was originally a crew of rodders in Utah/Nevada back in the mid/late '60s, these guys were using the original MOPAR full time transfer) the entire drive assembly is in a tunnel, with the seats off to the side of the tunnel. Makes for great ground clearance & almost unlimited power transfer to all 4 wheels. Good luck & have fun! BTW Happy Easter!

John v L
Minnesota

[madamstn]

I passed through again, what happened to the project. There are several vehicles that have drive shafts on the passenger side. I also noted you mentioned using solid shaft instead of tubing. Bad idea. Something else first though, Universal joints usually are prelloaded, I think up to about 4 degrees. Check the engineering specs of the joint manufacturer. The hard part. PSSSS! Do you really want me to explain the tube driveshaft. Lets consider a flat piece of metal - a leaf spring-just1 the two ends are on something. Push down in the middle of the spring. You are trying to stretch the bottom of the spring and compressing the top of the spring. Most of the middle is doing nothing. Its the surfaces. Thats why you have more than one piece in a leaf spring. The drive shafts are the same way. I can't believe I missed that. Like the man said universal joints can only be bent so far. I don't remember what you were doing I sorry its late, but this is a bad idea particuarly if you are going to add high impulse torque. Like 300 hp,6000 rpm, and pop the clutch. stand back. You would have to do the numbers, but at some point, things really would start to break. Let us know. good luck mark

[Triaged]

Originally Posted by madamstn

...I also noted you mentioned using solid shaft instead of tubing. Bad idea...

If you do it right I believe a smaller shaft would be better. It would be nice to have it gun drilled for weight reduction but that is not necessary. What you would end up with would be a long solid shaft that is splined on both ends. Something similar to a half-shaft (which sees more torque than a drive shaft because of gear reduction). It would act like a torsion spring helping to absorb things like clutch drops (that a tubular drive shaft would not). The key is that it would have to be made right and that doesn't come cheap.

[madamstn]

you got it right. I really like torsion bar suspensions- very clean. But you have to do it right. Besides that you are going to get a harmonic flex at some point that shaft is going to bend in these lengths. Drill it out. I am guessing but at about 3 feet, put the pressure on it and it's going to bow. Put a bearing in the middle and it.s going to shear-twist in two. If you are going to do this find somebody to do the numbers. I haven't been a design engineer in years. I think you can do it, If you don't run the numbers trial and error could be very expensive, as you know. I have a example,.keep it simple. Somebody I know built a piece of machinery with a 5 in shaft. the drive chain sprocket was mounted close to a bearing-he kept breaking the shaft. The set up should have acted like a torsion bar.the sprocket was so close to the bearing he had no torsion flex-He kept shearing a 5 inch shaft, 5in--A foot long 2 in shaft worked fine.I certainly know the book never replace expierence,B I have a math major,a physics major, and a mechanical engineering major, and taught 3 years in college, And I have been out too long to do this.I hope you do it, The other thing is safty-that thing can come out of there with terrible results. Do racing rules still restrainers, certainly scatter shields I considered a while before I posted this , being winded even for me, and pushy. I don't want to be bearer of bad news, so I apologize for my negative attitude,but I don't want to see anybody get hurt either. I may well be that I am out of the ball park, but till you do the numbers, you won't know.I will give my assistance any way I can.good luck. Mark A. Adams P.E.

[65Stanger]

In my experience drive shafts with joints in the middle work well. The 2000 Toyota Tundra? I believe has them stock.

[madamstn]

Agreed. I have been thinking- I would say go look at a large dump truck. They are frequently 3 or 4 sectiond. The fact that are used under high stress situations means they are sucessful, and you can guess as opposed to running numbers.I had a college proff that could guess closer than I could calculate, that's what 40 years of expierence does. My specialty is processing light weight paper, lots more interesting than it sounds. But thats why I PREFER not to do this.I am pretty good with gas dynamics-turbos and like. .Thanks, Good observation. m PS If you want the torsion spring effect, you can put one section say 24 inches in. I keep thinking about dodge pickup front bars, I don't think they are big enough. How many ftpds, are you putting out-any body?