Last night while attaching the split wishbone ends to the outside of the frame I discovered something that's now worrying me. I'm going to have new hubs made for using BMW discs and callipers but if I place the wheel mounting surface in the same spot relative to the stub axle then the tires will hit the wishbone arms when turning sharply. The only way I can see to prevent that (apart from modifying the stock Chevy rim I'm using) is to move the wheel mounting flange further out. The main cause for this I reckon is the wishbone arms now running near parallel instead of the angle they used to be which obviously gave the required clearance. How do you guys get around this problem???
This often comes up and you are right, moving the wheel flange will correct that problem but may create a new one having to do with wheel/tirel/hub/bearings/road alignment. Make up spindle stops which will prevent the tire rub and live with the enlarged turning radius.
I'll have to go through all the Chevy rims I've got with the hope there are different ones. I don't even know if Chevy did make stock rims with different offsets. The tires I'm gonna use are 165's. Is it worth having the centers on stock rims moved inward for less backspacing? I have thought about that but don't want to lose too much turn turning radius. My Nissan pick-up has a fairly large turning radius. I can measure the angle it's wheels sit at full lock and aim for that if there's a big enough difference. I don't like the idea of moving the flange out too far as it will place increased load on the bearings. On the other hand, the BMW's flange (source of callipers and discs) sit about 1.28" out from the centre of the hub. The hub's got a total width of 3.5" and the flange is about 0.5" in from the outside. That sounds easy enough. ::: How about a combination of reducing the radius and moving the flange out?
My solution was not to split my '39 bones all the way to the frame rail - just enough to allow the space for the gearbox. I still get the original turning circle with 6.00 x 16 tyres on ugly stud rims.
I'm using a stock '38 axle with "straight" bones (not the ones with the kick-up toward the front). Due to the height I want the frame I can't put the bones under the frame. The frame sits nicely in between the bones and the rear attachment points on the frame is basically at the top edge of the frame.
i see your problem,and i've ran into it before.a 38 axle has a wide perch center(38 1/2") causing the wishbones to be further out.if you run a stock 32-36 axle it will have a narrower perch center(36 3/8") which will bring in the wishbones.doing that will gain you some more turning radius.a 32-36 axle has a 2" boss at the wishbone,so you will need to make a 1/4" shim to fill the gap to your 2 1/4' boss wishbones. hope this helps. -danny
If you have access to a 1928 - 1936 axle you could possibly use that, as the spring perch to kingpin distance is longer. I have seen split wishbones that were bent at the right place to allow for more tire clearance. I doesn't look the best, but I guess it worked.
I used 2" thick wheel adapters to solve this problem. Cost me $75.00. I didn't have to modify anything, just bolt them on. Worked great. May have made it harder to steer, but not hard enough to matter.
Richard D replied with: "May be tough to find parts in oyur location(hence i won't give you **** for discs, esp. BMW!) but Model A axles have more space between the widhbone and spindle." but suddenly his reply dissappeared. Thanks for the wonderful advise guys. Danny, yes it does help but unfortunately I'll have to make a major design change to the front of the frame if I wanted to go this route. Due to me always wanting to be different, my front cross-member actually sticks out p***ed the outside of the frame. Something sort of like this: My headlight mountings are coming on the ends of the front cross-member and I feel that's going to be one of the key characteristics of the car. So, unfortunately the earlier axles also won't work. In the drawing the spring is still wider than the wishbones but in fact it's been shortened and will sit between the wishbones. My main reason for installing discs is safety. I tend to be hard on the brakes and want lasting stopping power. I've looked around for other donors long enough now. Nobody's got Volvo 122S spares and VW bugs with discs are non-existant here. I had a look at a GM car (Opel Rekord) but the hub design is too complicated. The BMW (E23 728i) callipers (4 piston) were cheap and new discs are also relatively cheap (surprisingly). The hub's external dimensions are very easy to duplicate over the stock Ford internal dimensions. I have already found a machine shop that will machine 2 new hubs for me with the BMW external dimensions and Ford internal dimensions. In fact I'm going there tomorrow to place my "order". Here's what the BMW hubs look like (on the car at the s****yard):
V4 beat me to it. P.S. There are 15 other H.A.M.B.ers in S.A., do you know any of them? http://www.jalopyjournal.com/forum/memberlist.php?do=getall
Ahh I see.... Oh yeah...my second reason, and maybe also very important one, is that it will be so easy to get the BMW disc brakes going. I want to use the Ford back-plates in any case to mostly hide the discs. The car isn't going to be traditional but I'm definitely not going to use all kinds of too modern stuff. Only the bare essentials like the front discs, vacuum ***isted m/cyl and Nissan 1/2 ton pick-up steering box. This steering box is also very easy to mount and is very popular a****st the local T-bucket crowd. The steering box will be mounted inside the cowl, thus totally hidden as well as the brake booster and m/cylinder. The only really visible "modern" parts will be the callipers sticking out through the clearance cut-outs in the back-plates.
Not so fast...what they did over here don't necessarily apply to what has been done over there for decades. Watch Mad Max or any other movie from overseas with modified cars in it. Mostly 4 door sedans, not many coupes, roadsters, etc. Maybe S. African hot rods have been having BMW discs for generations! P.S. What kind of CAD are you using?
My tires hit my unsplit wishbone, but just when I'm parking. Doesn't seem to a problem right now, with no engine in the car...
Pussies, drive the ****in car like the rest of us and dont worry............You ***holes gave us Seether anyway.........
I don't know if this would move things enough, or if it wouldn't cause other problems, but would it be possible to make a notch in the outside of the frame and move the mounting point inward? Sence you mentioned that the bones are running that high up, it seems to be the only way that I can think of to move them inward. Of course how this relates to the body is another issue. Good Luck!
Here is what I referred to with my earlier drawing with the front cross-member sticking out p***ed the frame. As you can see it's sitting between the wishbones leaving no space for the rear ends of the wishbones to be moved further inboard. I will aldo be adding a panhard bar to prevent them from hitting the frame. As you can see I still need to weld in the bush sleeves in the perches on the wishbones and then install shackles. I might also have to bend the tie-rod for clearance under the spring.
Oh I forgot....I'll be installing a larger acorn nut or something on the bolt holding the kingpin to reduce the turning radius. Just a little goes a long way in terms of allowing me to move the wheel mounting flange inwards to a point where it won't place too much stress on the bearings. This is what the 1400 Nissan 1/2 ton steering box looks like that I'll be using. This is also what all the local T-bucket guys use:
I appreciate you wanting to be different, but maybe save a bunch of headaches by t******* the front x-member and bending the wishbones. Are you going to trim off the old forward spring mounts?
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