DIY three piece cross member.
07-11-2012, 06:52 PM
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DIY three piece cross member.
I made the blocks out of eight pieces of 0.5" X 1" stock cut 2" long and four pieces of 0.25" X 1" cut two inches long.
Four of the 0.5" thick blocks are drilled with a 10mm clearance hole. Four of the 0.5" thick blocks are drilled and tapped for a 10mm bolt. The 0.25" blocks are drilled with a 10mm clearance hole.
Basically, I bolt one 0.5" clearance block to a 0.5" tapped block with a 0.25" block sandwiched between. When welded to the cross member, you remove the 0.25" block and cut with a band saw between the larger blocks. When you install the cross member back into the car, you insert the 0.25" blocks as spacers.
I ground down the small lip circling the outer perimeter of the cross member in four short sections, so the blocks would sit flush on the metal. The back of the blocks have a 45 degree taken out of them to avoid the radius on the bent cross member.
Also, the blocks are close enough to the four steering rack bolts to prevent them from turning. No more ramming allen wrenches where the sun doesn't shine.
Hopefully there are no clearance issues when I bolt it up, if so, I will break out the angle grinder.
Four of the 0.5" thick blocks are drilled with a 10mm clearance hole. Four of the 0.5" thick blocks are drilled and tapped for a 10mm bolt. The 0.25" blocks are drilled with a 10mm clearance hole.
Basically, I bolt one 0.5" clearance block to a 0.5" tapped block with a 0.25" block sandwiched between. When welded to the cross member, you remove the 0.25" block and cut with a band saw between the larger blocks. When you install the cross member back into the car, you insert the 0.25" blocks as spacers.
I ground down the small lip circling the outer perimeter of the cross member in four short sections, so the blocks would sit flush on the metal. The back of the blocks have a 45 degree taken out of them to avoid the radius on the bent cross member.
Also, the blocks are close enough to the four steering rack bolts to prevent them from turning. No more ramming allen wrenches where the sun doesn't shine.
Hopefully there are no clearance issues when I bolt it up, if so, I will break out the angle grinder.
07-11-2012, 07:05 PM
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The inside blocks on the middle piece have the holes drilled at 1.375" from the bottom of the block. The outside tapped blocks and the spacers are drilled 1.125" from the bottom. This makes the inside blocks sit a little lower and follow the cross member curve.
*edit - I just did a test fit and everything looks great. The oil pan should clear and come down just fine with the outside pieces holding the motor by the mounts. It will be cleaned up and powder coated for complete installation this weekend if all goes well.
I decided to not run with the heat shields and instead sheath the motor mounts in firesleeve. I'll be covering it in two diameters, 4.5" and 5", both layers combined will be 0.25" thick. It has a 1500F continuous exposure rating. I'll be coating each layer inside and out with end dip seal. It will help prevent abrasion and stop contaminates from wicking into the firesleeve.
*edit - I just did a test fit and everything looks great. The oil pan should clear and come down just fine with the outside pieces holding the motor by the mounts. It will be cleaned up and powder coated for complete installation this weekend if all goes well.
I decided to not run with the heat shields and instead sheath the motor mounts in firesleeve. I'll be covering it in two diameters, 4.5" and 5", both layers combined will be 0.25" thick. It has a 1500F continuous exposure rating. I'll be coating each layer inside and out with end dip seal. It will help prevent abrasion and stop contaminates from wicking into the firesleeve.
Last edited by destructo_low; 07-11-2012 at 07:37 PM.
08-16-2012, 04:29 AM
#5
A little late reply, but came across this...
I would guess the cross member is quite a structural element of the front of the car. When assembled, it's a square tube cross section. However with only two bolts holding the U together, you loose quite some torsion strength. On a road car it won't be too bad, but with stiffer springs on a track, I'd guess one could feel the difference...
Is it back in the car all ready? And how does it fit and does the car feel different?
I would guess the cross member is quite a structural element of the front of the car. When assembled, it's a square tube cross section. However with only two bolts holding the U together, you loose quite some torsion strength. On a road car it won't be too bad, but with stiffer springs on a track, I'd guess one could feel the difference...
Is it back in the car all ready? And how does it fit and does the car feel different?
08-16-2012, 06:39 AM
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A little late reply, but came across this...
I would guess the cross member is quite a structural element of the front of the car. When assembled, it's a square tube cross section. However with only two bolts holding the U together, you loose quite some torsion strength. On a road car it won't be too bad, but with stiffer springs on a track, I'd guess one could feel the difference...
Is it back in the car all ready? And how does it fit and does the car feel different?
I would guess the cross member is quite a structural element of the front of the car. When assembled, it's a square tube cross section. However with only two bolts holding the U together, you loose quite some torsion strength. On a road car it won't be too bad, but with stiffer springs on a track, I'd guess one could feel the difference...
Is it back in the car all ready? And how does it fit and does the car feel different?
I would rather see two bolts per side as high up and as low down as possible. This would increase the effective lever arm for the joint by a factor of approx 4.
If it would fit a better solution would be to weld a top plate to each of the side pieces of the Xmember that bolt into receiving plates on the centre pisec, and bottom plates on the centre piece that bolt into receiving plates on the side pieces of the X member.
