23-09-2020, 09:32 PM
Tubular radius arm setup on my special. This is a Big Seven front axle, but something similar wouldn't be to difficult rig up on a Seven beam. The tubing is 3/4" 16 SWG CDS. What's at the other end is in the second photo. The clevis joints allow adjustment of the castor angle.
![[Image: 40538556054_eb7a22fc3b_z.jpg]](https://live.staticflickr.com/869/40538556054_eb7a22fc3b_z.jpg)
John, you don't say if you're intending to remove the front crossmember when you move the engine back in the chassis, if you haven't lowered the chassis massively, it will be in the way of the gearbox/crankcase/sump. If removing the front crossmember turns out to be a necessity, you can just install a crossmember further back in the chassis. This is the tubular crossmember I fitted to my special along with the tube radius arm setup as part of a suspension and steering tidy up 35 years ago. It's 3" diameter ERW tube; about 14 SWG from memory, was in fact previously the tube section of a Vauxhall Cresta propshaft, I suppose if you're going to compete in VSCC, you could say that it came off a Bentley or such..
The centre pivot is a 1/2" Teflon lined rod end. this crossmember is much stiffer and lighter than the factory item.
![[Image: 50376470421_f622cfdeb5_z.jpg]](https://live.staticflickr.com/65535/50376470421_f622cfdeb5_z.jpg)
If your build does preclude any kind of centre pivot, you will need twin radius arms on each side with full articulation as Paul says in the post above. This means twin joints each side one above the other at the axle beam end, and twin joints one above the other at each chassis side. this is the only way to get movement of the axle, preserving the castor angle and dealing with the torque effect on the axle under braking.
John, you don't say if you're intending to remove the front crossmember when you move the engine back in the chassis, if you haven't lowered the chassis massively, it will be in the way of the gearbox/crankcase/sump. If removing the front crossmember turns out to be a necessity, you can just install a crossmember further back in the chassis. This is the tubular crossmember I fitted to my special along with the tube radius arm setup as part of a suspension and steering tidy up 35 years ago. It's 3" diameter ERW tube; about 14 SWG from memory, was in fact previously the tube section of a Vauxhall Cresta propshaft, I suppose if you're going to compete in VSCC, you could say that it came off a Bentley or such..
The centre pivot is a 1/2" Teflon lined rod end. this crossmember is much stiffer and lighter than the factory item.If your build does preclude any kind of centre pivot, you will need twin radius arms on each side with full articulation as Paul says in the post above. This means twin joints each side one above the other at the axle beam end, and twin joints one above the other at each chassis side. this is the only way to get movement of the axle, preserving the castor angle and dealing with the torque effect on the axle under braking.