IFS spindles on a solid axle

Im thinking about putting spindles off an MGB onto a solid axle, perhaps a modified A. New king pins to go thru new fabbed ends similar to a T should do it. Whats wrong with using IFS spindles on a solid axle?

 

U R asking for it

 

Whats wrong with using early Ford spindles?

 

And I ask, whats wrong with thinking outside the box?
Stuff like this is what Hot Rodding is based on.
We don't know what he's building or the need he's trying to fulfill by using those spindles.

Besides...he isn't asking how to install the latest trinket from BILLET SUPPLIES here.

Comswab...you'll need to concern yourself with the kingpin angle and the spread between the mounting lugs of the spindle. Also the need for the lug to be machined squarely to accept the thrust bearing.
Stuff like this has been done before...but not by me, so my help isn't what I'd like it to be.
Pictures would be a great help for us all though!

 

"Like a T"? You mean the spindle has a single boss with two bosses on the axle? If so, you're going to have to do some serious fabricating to make it work. I get nervous when I hear guys talk about welding on an axle. It can be done, but you better be an expert welder!

 

i'm sure it could be done , but it would be a lot of work to end up with spindles that use small rotors with 4 lugs. depending on what this will all go on , you would probably also want to adapt bigger brakes

any pictures ?

 

Now thats a very good point!

 

You'd have a long kingpin for no good reason.

The cost of fabbed parts.

Probably looks uglier.

 

Ok. it isn't as crazy as it sounds. The MGB suspension (at least for some years) uses a kingpin like a lot of the older American independent suspensions did. It's a but bulky and busy but it is a spindle that mounts with a kingpin. I found some photos by doing an Ebay search for MGB Front spindle and cam up with this 380210157746

CS you would have to build that axle with king pin angle that matched what MGB had to begin with. If you have to have someone else do the work it is going to end up costing more than buying a front axle from a supplier.

But if you or your buddy is a top rate welder an you have access to a full service machine shop it can be done.

 

This may not be such a far off idea. IDK what a MGB spindle looks like, but the 49-54 chevy spindles that get used on tube drop axles are from an IFS design. Post a picture of a MGB spindle, and let's see what you're working with.

 

Pat Gahnal did a piece in Rod n Custom, way back, and it was about chevy spindles. Seems that IFS and straight axles used different spindles, something about caster or something?? something to checkout.

http://66.154.44.164/forum/showthread.php?p=2323459

 

I saw a 27(?)Model T at the LA R Show many years ago, that was built in the 50's I think, that had spindles still n the uprights that at least looked like MG stuff.
The memory is fuzzy but I think it had a solid axle (with split bones and a X-spring?) locating it holding one end of the upright and another X-spring(?) above with the upright attached to it with pivots at both ends so it could articulate. then the spindle was in it's usual location on the upright.
IFS of sorts that retained the look of a beam axle.

Remember, that MG IFS has been around since around '52.
I'm sure more than a few parts of it have found their way onto "traditional" hotrods.

 

That link you posted talks about the difference between car and truck spindles. It's the car spindles that are used with the new fab'd tube axles.

 

Kingpin Inclination is the issue. (angle of kingpin in degrees from a vertical centerline)

Chevy was 7*, early Ford 10 or 11...

I once had to install Chevy spindles on a '40 Ford front axle. I literally had to bent the entire "smile" out of the axle, looked like $hit! (that's 'poop for pay')
The '32 pickup had little to no return to center (after turning; wheel would NOT return to center...big surprise...I warned him...)

he later bought a Super Bell I beam and .40 Ford spindles and brakes. A 'relief'.

 

MGB front suspension from MOSS catalog
http://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29020

Nick

 

yes car axles are IFS and truck axles are straight axles and they have different spindle 'king pin inclination'. I was just giving that info to be aware of in case it makes a difference.

 

OK back home from work and able to answer some questions, first off I don't have any pictures as I haven't started yet. Im just trying to weigh my options and see which might be the best option. In response to welding and fabrication my buddies and the shop Im going to be doing this at has 2 verticle mills, 2 horizontal mills, a couple of lathes. They are experts at welding tig, mig, stick and can weld aluminum, bronze, stainless, cast iron (expensive rods), and even steel. The cost is nothing if I can do the prep work.

The reason for using MGB spindles is that I am using a MGB rear end as the wheelbase and track matches what Im building. The track matches the front but the real reason is so that I can use MGB brakes all around (power brakes with a remote booster) drums in back and disc in front. Also having bearings, brakes, all the hydraulics available is a big positive.

 

Heres a diagram of the MGB front suspension. What is the difference between king pin inclination and camber. Is the camber the angle of the entire wheel off center when looking at it from the front of the car and king pin inclination the angle of only the king pin when viewing from the same position. I can see how these could be two different angles if the spindle and king pin are not 90 degrees. Then it would become a matter of simply insuring that the wheel had the correct camber when assembled and that would be a matter of what angle the king pin is drilled for depending on the spindles.

 

Kingpin inclination/steering axis inclination = angle of kingpin axis from vertical in front elevation.
Camber = angle of stub axle axis from horizontal (i.e. wheel from vertical) in front elevation.
They're not the same because the stub axle axis isn't at right angles to the kingpin axis.

Your reply to me on the Indy roadsters for the street thread:

I'm intending to fabricate a tube axle for the '31. It is not that out there and has often been done. I'm sticking to the Model A type of track, though, because I'm using A fenders, and moreover my handling aspirations won't allow me to give up any track. Hence the final product might look a bit wide.

However, I am definitely looking at discs all round. Discs on early Ford spindles is likewise no biggy. Even with discs of unusual provenance it's a case of an adaptor plate that bolts to the spindle in place of the drum backing plate. It's a case of proper measurements: and it isn't as if there isn't going to be quite a lot of fabrication on either of our projects. (My problem is rather that the MGB brakes are a bit small for my liking. I might have trouble finding suitable large-diameter discs that will bolt up to the MGB hubs - though the mere fact that the adaptor plates will be fabbed up gives me a bit of leeway.)

Having said that, there is a lot to be said for using the MGB spindles in a T-style "reversed" kingpin arrangement, if your axle is going to be fabricated from scratch anyway. That means that you'd simply make the axle to the kpi/sai you need to get the final camber you want. I would recommend locking the pin in the spindle and running bushes in the axle. That way the distance between the bushes is the greatest you can get, and the fact that it is greater than with a conventional axle by some margin might make for a set-up that will keep its precise feel for a long time. This is because the lateral forces on the bushes are less for any given torque than with a conventional axle.

The downside is an axle that is at best funny-looking and at worst downright ugly, depending on how it's done. But even funny-looking might be in keeping with the build: think Frazer-Nash, etc.

If you do decide to go this way, please give me the benefit of your measurements, as you just might convince me

For the record, the stub-axle on an early Ford spindle is ¾"Ø (19.05mmØ) at the outer bearing and 1.19"Ø (30.21mmØ) at the inner. The MGB uses the Timken Set2/Set6 combination in common with a very large number of other cars that have stub axles of ¾"Ø (19.05mmØ) at the outer bearing and 1¼"Ø (31.75mmØ) at the inner.

That means you'll need a sleeve with a wall thickness of .030"(0.762mm) to run MGB inner wheel bearings on an early Ford spindle. I haven't compared stub-axle lengths, and consequently don't know how spacers might affect whatever brake conversion one does. I suspect that the early Ford stub-axle is a bit longer than average. Can anyone elucidate here?

 

Before I forget: apparently the current wisdom on MGB front brake upgrades is to use 294mm (11.6") BMW "Mini" vented discs, with appropriate bracketry.

Edit: with 18" or more of rim to play with one might as well investigate the rear discs off a Cadillac STS-V: 365mm (14.4") vented, at stock MGB height.

 

i don't see why you would do it. is there some advantage you're going for that i'm not seeing?

 

He most likely already has the MGB parts in hand. He also has access to a full machine and welding shop where he and his coworkers can build an axle from scratch.

C/S The first thing you need to do is get the exact alignment specifications for the MGB What you need are Kingpin inclination and you will need the camber specs. Caster will be adjusted with the radius rods later.

You will have to set up the axle so that the kingpin inclination is correct for the MGB spindle and that will probably include milling the end of the axle at the correct angle to accept the sleeve for kingpin before welding it to the axle. There is a fairly decent explanation here http://www.tpub.com/content/construction/14050/css/14050_281.htm that should help you figure it out.

 

A few random thoughts;

Looking at the above drawing of the MGB components, it appears that constructing an axle to utilize the entire MGB upright would be dead simple. Two flat plates welded to your axle tube of choice to carry the MGB outer control arm pins would do the trick. The ultimate shape of said plates would be dictated by the MGB spindle designed in king pin inclination, clearance issues, axle tube shape (arch, drop, etc.), axle tube diameter, and your personal design ascetic.

Caster is simply the angle (usually stated in number of degrees) fore or aft (positive or negative) from perpendicular of the ground plane in side elevation of the king pin axis. This can be easily done by rotating the axle tube relative to it's mounts, negating the need to worry about it at the king pin boss.

If you desire rack and pinion for steering, mounting it to the axle itself eliminates any bump steer issues. Since the advent of the collapsible steering column, u-joints, slip joint shafting, and/or trunions (spl?) are readily available to allow the limited up and down movement necessary for such an arrangement.

 

It would be much easier to just modify early Ford spindles to accept the MG brakes, via some combination of machining, sleeves, adapter plates, and new bearings. Guys have been doing this type of conversion for years for a variety of brakes. It's gotta be easier, safer, and better looking than trying to use the MG spindles.

 

King pin inclination is the angle of the king pin from perpendicular to the ground plane (again usually stated in number of degrees) looking at the suspension from the front or rear elevation. With zero camber the axle stub is going to be parallel to the ground so you could say perpendicular to the axle stub in that case and be right also. You want the king pin axis to intersect the ground at the centerline of the tire tread to minimize tire scrub and this is easily obtained for any wheel hub mounting flange for any tire diameter by varying wheel offset.

 

Building an axle from scratch to connect to the ENTIRE MG upright with the stock MG control arm pins sounds like the easiest and most elegant solution of all, with no chasing down or remanufacturing of oddball adaptors or spacers in the event of a repair needed down the road.

 

twofosho- Excellent idea I love that a lot more than having to build and adapt king pins, as you mention an elegant solution. Ned the rims are 15 inch not 18 so the cad brakes mentioned would be huge. Running the stock mgb brakes should be very good as the car will be considerably lighter than a mgb. Looking at this merc front axle it even appears that the axle lends its design to work with the entire stock spindle with the mounting bushings. As for steering I love the feel of rack and pinion and the looks of a side mounted pitman arm.

 

Commodoreswab, what wheelbase and track are you looking at? I see the SSKL has the exact wheelbase and track I've been working to for my '31 project. Even so I'll have trouble emulating those 33" tyres! The more realistic 28" height I'm going for does affect the proportions materially, though no more than to omit the "kurz" from the "SSKL". The proportions will be believable for a "standard short" wheelbase.

That's why I assumed that you would be lacing your MGB centres to something a bit bigger than the stock 14", or even 15", rims: I'm looking at 5.5x18" motorcycle hoops. If you're going for a 100-105" wheelbase to correct the proportions it explains why an early Ford axle is too wide.

But that Mercedes axle looks interesting with those forked ends. I'd like to see some more detail.

Edit: here's a photo:

 

Im not trying to copy a merc but use it more as a piece of inspiration. I am using stock MGA wheels for now (would like to upgrade to something with more spokes in the future). Think of my build as being more Miller inspired, lets build a small lightweight car instead of a more massive monster. Ive sketched up a rough drawing, the wheelbase is around 95 and the track around 49 so its a small car. The wheels in the drawing are the correct size for mga tires.

 

As you're working with MG bits you might also take a look at the MG K3 for inspiration:



My '31 project has undergone considerable metamorphoses from its origins as Model-A-based to its current status as Model-A-based, now locked in due to my having acquired a '31 firewall and a Deuce shell. Along the way it was Model-T-based for a while, and for a short time it was an MG K3 replica.

The story here was that a local used car dealer near my office had a VW-based MG TD replica on their lot, but grossly overpriced. I was watching to see if the price would come down to a realistic level, and in the process had the idea of "de-faking" the thing. That is, losing the Beetle floorpan and substituting a ladder frame, front-mounted water-cooled engine, and beam-axle front end. As it was registered as an MG I even had the plan to sling a detuned Audi 5 in the back for the roadworthy inspection and then transfer it to the front at my leisure afterwards. It might be a weird choice of engine but in the right state of tune those things can have quite an appealing sound.

But this, to cut a long story short, required a bit of a wheelbase stretch, and as I was going beam axle it wasn't going to be any more a TD than it was on the VW chassis. Looking around for an historical precedent turned up the K3: right size, cool proportions.

But things moved on. The TD replica was sold, I found some bits, and the '31 is a '31 again.

Not to take over your project, but I think we might have thick wads of notes to exchange