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NAPA 68
11-18-2010, 06:49 AM
What experience have some of you had with the maximum length for a 1 pc. driveshaft? As some of you may have seen, I am in the process of building a 59 Bel Air. I was curious what the parameters are for determining when a person should have a 2 pc. shaft. BTW, the car will require a 57" shaft center to center on the yokes.

Thanks,

Tim
61ragtop
11-18-2010, 01:25 PM
Not sure on the max length but you might obviously have an issue with the X frame unless you plan to custom build a frame. I think the Chicayne had a 2 piece still and they ran over 1100 hp through it with no problems.
NAPA 68
11-19-2010, 05:40 AM
Not sure on the max length but you might obviously have an issue with the X frame unless you plan to custom build a frame. I think the Chicayne had a 2 piece still and they ran over 1100 hp through it with no problems.

I should have thought of that. Moose is a close friend of mine. I'll call him!
Thanks for helping me get my head out of my ass!
61ragtop
11-19-2010, 04:40 PM
Hey no problem thats what we are all here for to help each other out!!:cheers:
GregWeld
11-20-2010, 05:15 PM
Napa ---

Here's a Rod and Custom article that gives you some food for thought.

http://www.rodandcustommagazine.com/techarticles/0608rc_driveshaft_tech/index.html
rwhite692
11-21-2010, 10:13 AM
My 1960 Caddy had a two-piece (factory) and it was necessary...but that car was an all-stock restoration and had a lot of suspension travel...If you are setting your car to ride low and with not a lot of travel, you may be able to get away with a one piece...

You could pretty easily make a mock-up driveshaft (plastic pipe, etc) to check it out and see what your angles are, X-Frame center section tunnel interference, etc at min/max ride height.

http://inlinethumb34.webshots.com/45601/1453114278011691741S500x500Q85.jpg
GregWeld
11-21-2010, 10:49 AM
Driveline length etc is all predicated on the "critical speed" the drive shaft will see.... so it has to calculated using the tranny gear ratios - rear gears - tire diameter - and red line.

The shaft DIAMETER will need to be increased as the length grows, and also the type of shaft material used, and that will depend on the critical speed of the shaft.

A little math -- or better yet -- some phone calls, or emails, to the big manufacturers should give you the right answers.