widening an mgb front crossmember
I just purchased a '59 Hillman Husky with an Olds Quad 4 conversion already finished. I promise pictures soon, it's a hectic week and I'm going to be gone the next few days. Anyway, one of the "problems" with the car that I'm not thrilled about is the stock front suspension and tiny drum brakes. The reasearch I've been able to do seems to indicate that the parts to convert to discs are either rare or quite expensive. Keeping in mind that I paid next to nothing for the car, I'm not really interested in dropping a grand on a willwood kit and it wouldn't do anything for the steering and suspension woes.
I was doing some measurements last night on the Hillman and a spare mgb crossmember, and it appears that approximately 8" would need to be added to the center of the x-member to get it in the ballpark to fit. No, the mgb suspension isn't the height of technology, but it's cheap, easy to rebuild, has decent brakes and I've always liked the handling and ride. The actual widening of the x-member doesn't seem like any big deal. How would I widen the rack? Could I just lengthen the tie rods? Would there be any aderse effects on geometry? Maybe an aftermarket rack could be found? I still need to do more measuring to determine if the track width would work out. The drive home home convinced me the car is fast enough that the drum brakes must go sooner than later. |
Bill Young Bill Young Kansas City, MO (1337 posts) Registered: 10/23/2007 09:23AM Main British Car: '73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep |
Re: widening an mgb front crossmember
Ryan, widening the B crossmember would be pretty straight forward. The rack is another matter. You could lengthen the tie rods but you would get some bump steer with that setup. I think I'd look at the rack from a late model Mustang and check the width. I've got a hunch it would be pretty close to what you need and offer power steering if you wanted. What you're looking for is a rack that measures between the inner tie rod pivot points as close as possible to what ever the B unit is plus the amount you widen the crossmember. If you can get within an inch you'll have a pretty good steering setup with minimal bump steer as long as you mount the rack at the same height as the B unit was.
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Dawie Dawie Coetzee Cape Town, South Africa (25 posts) Registered: 04/17/2009 07:53AM Main British Car: 1958 Morris Minor Subaru EJ25 (planned) |
Re: widening an mgb front crossmember
Another way around the steering thing is to introduce a pair of idler arms. Make sure the tie rod inner joints attach to the idler arms in the right place relative to the suspension control arms, then make up a pair of intermediate tie rods from the idler arms to the rack. To limit lost motion I'd be inclined to use high-quality spherical rod-end bearings for the new joints, and perhaps run the idler arm pivots in needle bearings.
-D |
Re: widening an mgb front crossmember
Thanks for the advice. Unfortunately, I did some more measuring last night and I really don't think it will work. I would have to widen the x-member 5-6" for the shocks to clear the outside edge of the frame rails. The mgb hub mounting faces are 51" apart stock, same as the stock Hillman hub-face width. So if I widen the mgb x-member to fit I'll end up with too wide of a hub-width. I might be able to figure out something with wheel offset, but I think it becomes too much of a pain. Back to the drawing board.
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Dawie Dawie Coetzee Cape Town, South Africa (25 posts) Registered: 04/17/2009 07:53AM Main British Car: 1958 Morris Minor Subaru EJ25 (planned) |
Re: widening an mgb front crossmember
Too wide a track has spoiled the looks of many a modified car! Here in South Africa someone heard about Jag IRS on T-buckets and got it wrong, with the result that the local hot-rod community considers it necessary to fit at least Jaguar front suspension on just about anything, even if a live axle is retained at the rear. There is no good reason for this, only the mistaken belief that it is standard hot-rod practice world-wide. There is no advantage to it, as the Jag IFS is not fundamentally different from any other pressed-steel double-wishbone system, certainly no prettier, and at least 2" too wide for anything one would want to put it into.
I've thought that Japanese light-truck torsion-bar systems might be more appropriate in a majority of cases. What's the Hillman suspension like? Perhaps a combination of small upgrades will do the job? -D Edited 1 time(s). Last edit at 05/05/2009 04:21AM by Dawie. |
Re: widening an mgb front crossmember
Well Dawie, from what I've read and the pictures I've looked at on the net, the Hillman front suspension is identical to the Sunbeam Alpine. I'm not familiar at all with Sunbeam stuff, but I imagine there were some differences over the years. I think that I could rebuild the stock suspension and add Alpine discs and it would be fine. But I'm not that excited about keeping the steering box with the strange linkage that travels up and over the bellhousing. And from what I've been able to find so far, used Alpine spindles and calipers aren't easy to find.
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Dawie Dawie Coetzee Cape Town, South Africa (25 posts) Registered: 04/17/2009 07:53AM Main British Car: 1958 Morris Minor Subaru EJ25 (planned) |
Re: widening an mgb front crossmember
A quick search reveals that you've got a 108mm pcd. It's quite a common pcd, used on most European Fords as well as the Fox platform, some Audis, early Alfa Romeos, and others. It's no absolute indicator, but if the rotors fit over the hubs, rather than bolt to the back, it might be possible to assemble some sort of conversion using Ford parts, and that would make some high-performance brakes possible. The trickiest bit is likely to be fabricating a caliper bracket.
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ToyBug Dan Wilson Colorado Springs (14 posts) Registered: 06/01/2010 10:09PM Main British Car: 1959 Bugeye Sprite, 50's MG Special Toyota 2-TC 1600cc, MGB 1800 |
Re: widening an mgb front crossmember
I realize that this is an old thread, but I am in the process of widening a B crossmember and rack by 5-3/8" for my MG Special. The crossmember job was accomplished by cutting two members apart assymetrically, and rewelding the two "long" halves. I bolted a plate across the shock mount pads to ensure some reasonable measure of alignment. The rack issue, which I thought would be an easy choice of the proper length rack, turned out to be not so easy. The ubiquitous Mustang racks are only 1/2" longer from tie rod inner joint to joint than the MGB. Custom racks can be had, for about 800 bucks.....My plan is to cut two rack shafts assymetriclly , machine the ends to make a pin and socket, and reweld. I'll pick up my second rack in the morning, and next week should have the parts together. I'll post pix on my 50s MG Special Project Journal this site.
The rack housing is easy to extend. I cut mine apart on the centerline, and made up a sleeve from 1-1/2" x 14ga. steel tubing. They fit very nicely without any massaging. The rack hosing ends will get bolted to the crossmember, and the sleeve will be tacked in place, then removed to be TIG welded for appearance as much as anything. The only reason I can see for the center part of these racks is to try and keep the oil/grease on the inside. I was concerned about the alignment of the rewelded rack itself, but note that it is supported on the offside by a bushing, and on the pinion housing side has no real bearing surface, being trapped between the pinion and the "saddle" above it. Not how I would have done it, but then I'm not an engineer, and hundreds of thousands of MGBs seem to have been ok with that, not to mention all the Cobra kitcars that also use the B r&p. Dan Wilson |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6469 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: widening an mgb front crossmember
Dan, I seem to recall hearing that the stock MGB steering rack is actually somewhat longer than ideal for proper geometry. As long as you are modifying it you should check this out. Curtis may have the details or a good search may turn them up. Seems to me they were off by something around 1/2-1".
Jim |
ToyBug Dan Wilson Colorado Springs (14 posts) Registered: 06/01/2010 10:09PM Main British Car: 1959 Bugeye Sprite, 50's MG Special Toyota 2-TC 1600cc, MGB 1800 |
Re: widening an mgb front crossmember
Thanks, Jim, I'll check into that.
I figured that widening the B rack the same amount as the crossmenber would basically not change anything for the steering geometry, as the only changes would be in the middle, and nothing different from mounts outboard. I did score the extra rack needed today at a local salvage yard, so have all I need to get the job done next week. I also picked up an extra steering column, the collapsing type. I am not that enamored of the collapsible aspect, but wonder if this column could be modified to allow an adjustable length without losing the safety feature. Anybody? And any better/smaller steering u-joints made to match the MGB splines? The stock B units seem massive enough for a 4x4 driveline...... Dan Wilson |
mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: widening an mgb front crossmember
Dan, On the U joints Wilwood,Sweet and Jag 3/4"X48 spline in Speedway Motors. An easier idea on the Rack would be Dodge Intrepid Center steer. Just use a piece of channel as adapter to put inner tie rods optimally for minimum bump steer. They are all power racks but can be modified for manual. Most are same ratio and lock to lock as MGB. Variable ratio and Sport(faster ratio)were optional.
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mgb260 Jim Nichols Sequim,WA (2463 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: widening an mgb front crossmember
Link to pictures of modified Dodge Intrepid rack: [www.mgexperience.net]
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