Speedster Firewall, Steering Column Questions

[ryanf1023]

I'm building the body for my speedster. I do plan to lower the steering column using the wedge/washer method. This will move the steering column away from the firewall. I'm hoping to find out how thick the firewall is to begin with, at least the horizontal distance from the firewall brackets to the front of the firewall in the driver's compartment where the steering column mounts. This will give me a reference, and I will be able to adjust based on the rake of the lowered column. My fellow T-er suggested a 3/4" thick dash if going vertical.

As well, I've a professionally rebuilt front end. The car will be using the standard straight axle with pre-1925 spindles. There will be no lowering of the car to start. I'm wondering if the steering column being lowered will affect the front-end geometry. My thought is the tie rod will compensate for any change in geometry of the pitman arm movement, and leave the front axle, spindles, and tie rod alone. Am I correct in my assumption?

Thank you,

Ryan

[Allan]

Ryan, my wide body Duncan and Fraser roadster sits at standard height, but has the steering column lowered and moved outboard as part of the body building process. This enables the body line to be lowered and the seat is also wide enough to take 3 slim adults.

There is a steel wedge between the frame and the lower steering bracket to accommodate the steering column height, and a thick wooden donut between the column base and the firewall to fill the gap created. This is a standard dealer/coachbuilder fitment.

The hole in the steel firewall is shifted approx 3/4" outwards and 1 1/2" down.
Hope this helps.

[kmatt2]

Ryan , I see that you’re in Alberta, but for this I will assume that your speedster will be left hand drive. In dropping the steering on a right hand drive speedster one would have to deal with the manifolds and carburetor. On the left hand drive car the dropped steering gear basically pivots in an arc from the lower frame mount, only moving back by the thickness of the thinest part of the wedge, maybe a quarter to half inch. On a 1917 or later make sure you mock your steering up with the correct frame to firewall brackets for a wood firewall, the 3/4 inch thickness firewall would be about correct. The geometry of the front suspension is controlled by the front spring peaches and the front wishbone to engine pan mounting distance, which is fixed. Make sure you use the correct front spring peaches for left and right side. Make sure to check for pedal clearance with the lowered steering column. The only other thing to look at is the drag link. Because the pitman arm moves up and forwards some you will need to measure the pitman arm ball to tie rod ball distance with the wheels straight ahead and the steering centered between full left and right lock. You may need to use a shorter 1926-27 drag link. If later on you change out your front axle to a dropped axle make sure to get a dropped and stretched axle to keep the kingpin to kingpin distance the same as your current stock axle is. Have fun with you speedster project.

[ryanf1023]

Allan, thanks for the info. I knew those were lowered, but I didn’t know they were moved outboard as well. That must add some breathing room between the column and the generator and intake assemblies. You’ve a beautiful looking T.

Kevin, I misspoke and meant to say drag link. Thanks for the clarification and the info. My car will start as a LHD, although I would like to convert once I have all the necessary RHD pieces. I didn’t even think about how a lowered column would add to the already existing difficulties of maneuvering the tight spaces on that side of the engine. Maybe I’ll just have to use those pieces for a conventional RHD body style.