Woodfin's SS GT/TB construction series

[Ken Haase]

Larry, assuming M/T #3074's, which they show as having 100" rollout and will probably grow 2"-4" at least at 130 MPH (I'm guessing at your teminal speed) my formula predicts 7920 RPM with 100% lock up. Multiply that by 1.05 for slippage and you have 8316 RPM. So, maybe you get a little tingle, LOL.

My '65 Chevelle with it's 115" wheelbase has a shaft approaching 60" and I think my guy is using 3.5" steel. Back in the day, I spit out a stock GM 'shaft at 100+ but it was because the u-joint failed. If you happen to be nodding off like I was, it will wake you up. And destroy you trans case as someone mentioned.
Ken

[Dwight Southerland]

Originally Posted by Dragsinger

also, it would be interesting to know what RPM others with 3.5" aluminum driveshaft 54" in length are spinning them.

Well, I do not know the length of a stock early Camaro driveshaft, but every one of those I drove or owned was way over 6700 rpm in the lights, and I never broke a driveshaft. And they were not 3.5" diameter and not aluminum.


In fact, the only driveshaft I ever broke was an experimental carbon fiber driveshaft that I spit out on the starting line at Baton Rouge.

[SSDiv6]

Originally Posted by Dwight Southerland

Well, I do not know the length of a stock early Camaro driveshaft, but every one of those I drove or owned was way over 6700 rpm in the lights, and I never broke a driveshaft. And they were not 3.5" diameter and not aluminum.

In fact, the only driveshaft I ever broke was an experimental carbon fiber driveshaft that I spit out on the starting line at Baton Rouge.

Dwight, the OEM Camaro drive shaft if 49.75" long without the yoke and 55" with them. The diameter is 2.75" and the tubes were thick walled DOM carburized tubes. Therefore, they were very stout from the factory. Usually, the U-Joints were the first thing to fail. Also, in the early days the slicks did not have the traction and grip of today's slicks and suspensions were not as good either.Although the RPM's were high, the engines did not make as much power as today's engines either.

[Dragsinger]

I noticed something good this afternoon. My stock of shiny parts is smaller because they are bolted on the truck

Sometimes the smallest of things gives me pleasure. I like neat plug wires and find the MSD two piece, snap together too bulky for my liking.

Instead, these small "help" looms from the local parts store look just right and fit the wires easily.

[Dragsinger]

in photo #183 notice the starter bump button

and two more photos of the mostly finished engine

[Dragsinger]

Ken,

I think your math is close. I had also estimated 8300 - 8400 engine finish line RPM. Gary Hettler suggested 8200 shift point so it's all fitting about right.

A few recorded runs with the Race Pac will tell the real story

[Bimbo Jones]

Larry during time trials at a Motorplex's bracket race they have the 1/4 mile clocks turned on. Several racers take advantage of that opportunity to make a few 1/4 mile passes before we start the 1/8th mile race.

[Geerhead55]

Larry,, that starter bump button looks like you could dial in some delay to it if you wanted to! The motor is looking good.
Danny Durham

[Sean Marconette]

Larry,
Do you have a similar button to bump the fuel pump for fuel check? Just a suggestion.

Thanks for sharing your build.

Sean

[Dragsinger]

Sean, good suggestion, the wiring is still working so it will be easy to add that. Thanks, good catch.

A button mounted on the motor place right there by the valve wold be a convenient tool.