Caster settings

[novacain]

       I'm building a '55 Chevy gasser car. I used a straight axle out of a '66 Chevy van. Does any body know how much caster to run with this set-up? I have 9 degrees in it now but, it gets the "death wobbles" at about 25mph. Anybody else have this problem?

[GlennLever]

Try putting this question to RooMan in his room.

http://www.frontenginedragsters.org/forum/index.php?board=25.0

[Dolmetsch]

I used those spindles on my dragster to the left. I use 3 degrees. The Death wobble as you call it (I wouldnt) is not caused by what you might think. A Steering damper  either Socal or Moog for VW beetle of 60s vintage will cure it.  It is not unusual to have this problem at low speeds with a solid axle. Playing with a toy Gryo will give you a better understanding of it. Just like a shock stops excessive oscillations of a spring after a bump the steering damper just says to the steering settle down, thats enuf.  Now from the practical side. My little rail had a bit of a problem very minor and not a concern at the Shannonville track which is relatively smooth. It would only show up on the return road if I got close to the edge of the pavement where it was rough. It would take a bump to get it started and was never an issue as it was a low speed. The car ran like it was on rails when racing. When I started running at Picton Airfield which was paved once in 1939 things were a bit different. Sometimes even slowing down from a burn through if there was an old seam in the pavement it would wobble. I didnt like it anymore then you but after many years of this I knew what the cure was. I ordered a VW damper and installed it in about 1 hour. The problem disappeared. Not sort of disappeared but gone completely. No sign of it whatever.   
Now How did I know what to do? Many moons ago in the early 70s I was involved with a 32 Austin Bantam with believe it or not a turbocharged slant six. It had a Thames panel (Like an Anglia) front axle and when rolling along at 15 to 20mph if it hit any kind of a bump it would do that. Like many I was sure something was wrong in design. I searched every avenue to try and cure it.  Several old lads told me to put a damper on it. Seemed wrong to me. However one day I swallowed my pride and bought a used one from our local wreckers. Never had another problem and that car is still racing BTW albeit quite a bit different than then. Many vehicles with solid axles come from the factory with dampers. So Cal says no car leaves their shop without one. I believe it is aggravated by the weight of the front wheels as well. A wire for instance might not have it at all while a heavier steel or aluminum wheel may have enuf inertia or mass to set it in motion. A damper will cure it .
So even if all this makes no sense and one is sure it is all wrong what will it hurt to try? It certainly wont hurt the car in anyway.
Don
Here is the car I first learned about this on way back in the day.

[novacain]

   Don,
   Thanks for the info. I'm going to give it a try and i'll let you know how it works out.
  Cool pic. I'll bet that thing was a blast to drive. What did it go?
                                                                                          Stan

[Dolmetsch]

High 11s. I never drove it with this engine although I built the engine (car was mine originally too but sold it when married. A friend bought it and asked me to partner with power) It was here late one nite for pre season service when the new (3rd)owner the late Brian Farrel owned it.   The usual stuff , check over motor, check valve lash and timing etc. I finished it about midnight and he was here to pick it up For some reason I seemed to know to take the extra time for a photo. This is what they did to it the next season. It is till running though and will soon have 40 years on it. Last I did a shakedown pass was with the turbo 170. It would run low 12s Probably 1976 or so. It gained zip with the extended modern frame BTW . Eventually they put a B seris Mopar in it which is still there. I think it lost a lot of cool with the update. Body was from Anderson and was one of his early ones.
Don
BTW The Black Willys behind belongs to my pal Mike Sietsma and is a C gasser in the vein of exactly how it would have been. It is powered by a 331 hemi with a single 4 bbl and Isky cam and runs about same as it would have back in the day which is exactly what Mike wanted. He also street drives daily if possible.

[novacain]

      Don,
    I went to NAPA and got a stabilizer for a Jeep Cherokee, made a set of bracket for the straight axle and it solved my problem.
Thanks again for the info.
                                                             Stan

[Dolmetsch]

I'm proud of you.
Glad you got it fixed. Never thought of a Jeep one but it is a good idea. I may install that on my VW gasser front end since it will need one for sure.
Don