After looking at the subframe designs of various others that have done engine conversions (both the 4EFTE and other engines), I sketched up a design that I believe will work well, allow me to insert (and remove) the engine easily and be more than strong enough to take the forces necessary. It will use a combination of 32mm diamater (OD) structural tube with 3mm wall thickness, and 6mm plate for the brackets and engine mounts.
The Mini shell I have shows evidence of a slight front push at some point in it's history so the engine bay and subframe may or may not exactly square, even after the new front valance is welded on. I don't want to go to a heap of effort to make a custom subframe while I don't have the shell, and then get the shell back and have the subframe not fit. It only takes a couple of mm out in one direction not to fit!
I know what the subframe will look like overall, so all I've done for now is cut out the engine bay inner panels in my front cut to make way for the side braces and also fabricate the brackets that will mount onto the front valance.
You can get an idea of the shape of the tube that will on either side of the engine from where I haev cut the inner panels.
The front brackets/mounts have been made from 6mm steel. The flanges on the outer sides of the bracket is where the side tubes will be welded to and there will be another tube welded between the two brackets running across the rear of the valance.
One interesting thing I have found already is the difference between the mounting points on the orginal valance versus the Rover-labelled replacement valance I purchased. Apparently around 1976 (in the UK only), the method of bolting in the subframe onto the body changed from solid bolts to rubber mounts (with a bolt though the centre). In the pic below (of the inside of the front valance panel - passengers side), the original subframe mount is the lower hole however in the replacement panel, this is a much larger hole in the same location. The new panel would normally have a teardrop shape rubber mount (located by the small hole at the bottom). I will simply weld a small piece into the large hole and redrill a small 10mm hole in the centre so that my subframe will have TWO bolts to mount it instead of the standard one.
The Mini shell I have shows evidence of a slight front push at some point in it's history so the engine bay and subframe may or may not exactly square, even after the new front valance is welded on. I don't want to go to a heap of effort to make a custom subframe while I don't have the shell, and then get the shell back and have the subframe not fit. It only takes a couple of mm out in one direction not to fit!
I know what the subframe will look like overall, so all I've done for now is cut out the engine bay inner panels in my front cut to make way for the side braces and also fabricate the brackets that will mount onto the front valance.
You can get an idea of the shape of the tube that will on either side of the engine from where I haev cut the inner panels.
The front brackets/mounts have been made from 6mm steel. The flanges on the outer sides of the bracket is where the side tubes will be welded to and there will be another tube welded between the two brackets running across the rear of the valance.
One interesting thing I have found already is the difference between the mounting points on the orginal valance versus the Rover-labelled replacement valance I purchased. Apparently around 1976 (in the UK only), the method of bolting in the subframe onto the body changed from solid bolts to rubber mounts (with a bolt though the centre). In the pic below (of the inside of the front valance panel - passengers side), the original subframe mount is the lower hole however in the replacement panel, this is a much larger hole in the same location. The new panel would normally have a teardrop shape rubber mount (located by the small hole at the bottom). I will simply weld a small piece into the large hole and redrill a small 10mm hole in the centre so that my subframe will have TWO bolts to mount it instead of the standard one.
Comments
Post a Comment