Rack and pinion conversion

[Mike Wright]

I am using one of the HEI distributors modified to work on an FE. My reason for this and going the Pertronix rout is simple. Any Jack Auto parts carries the GM module. Sometimes your local auto parts store may or not have the pertronix module in stock. Also if in the future I wish to add TB fuel inj. a simple change to a 6 wire module will give me spark control from computer..

[scumdog]

I am using one of the HEI distributors modified to work on an FE. My reason for this and going the Pertronix rout is simple. Any Jack Auto parts carries the GM module. Sometimes your local auto parts store may or not have the pertronix module in stock. Also if in the future I wish to add TB fuel inj. a simple change to a 6 wire module will give me spark control from computer..

I simply carry a spare points/condenser set up in the trunk of my Thunderbird ‘just in case’ my Pertonix dies.
The Pertonix in the Mallory twin-point in my F100 did die a few years back so when I replaced it I also bought a second one I now carry in the glove-box ‘just in case’.
( BTW: Pertonix costs US $80 BUT in this country will set you back NZ $300!)

[bygrace]

curly-cues???

Sorry to make you rewind to your 8/29 discussion, now that you're on to an ignition topic, but I have to ask about your mention of Ford's use of "curly-cues" to reinforce the boxed unibody frame members. Could somebody explain them? I think brushwolf was then into rack steering chat with simplyconected. I've done a rack, and wanted a fourth hole below the steering box location, but I wasn't too pleased with my method of getting a tube in. I'm also thinking about the same issue in regard to mounting a bolt-on rear sway bar. Would Ford's solution pertain? What else you got for reinforcement? Thanks, Mike S.

[Brushwolf]

Dave can probably elaborate more specifically, but I have cut up frames and the pieces he is talking about are just "S" shaped metal about the thickness of the frame rail that are inserted inside frame during frame construction.

Actually, they aren't necessarily actually "S" shaped either, but they are bent to allow them to provide support for the inner side of the frame for all the bolt holes in a given frame area.

Some of them have notches thru frame side where tabs from these pieces are extended thru frame notches, then bent over and welded on the outside of the frame. So, it makes the frame pretty much crush-proof as far as bolting on the steering gear and idler arm brackets.

Pretty hard to get something similar in frame after it's already built, presumably why Dave recommends using existing reinforced frame holes when possible. Saves a lot of work.

Most late 50's Fords also have holes on the bottom of frame for PS Ram mount, but I have found that only the originally PS equipped full size cars also have a weld-nut bracket inside frame there.

So, it requires some extra frame work if adding PS to a car that didn't previously have it, being there is nothing to thread Ram mount bolts into otherwise.

Prior to working on a 57 Fairlane, I figured if the Ram mount holes were there, the threaded pieces inside the frame would be there too. But they weren't, on the 57 Fairlane anyway..

As far as adding a reinforcement to an area that had none, you are probably stuck with drilling a large enough hole to accommodate a very slightly oversize inside diameter thick-walled "pipe-type" piece going completely thru the frame and tapering the outside pipe perimeter prior to welding, then welding both sides to frame and grinding it flush (assuming whatever you bolt to it needs a flush mounting surface).

If it doesn't require a flush mount, it could also be done with the "pipe-type" insert being wider than the frame and welding the piece in leaving straight ends to mount to. (Wouldn't actually use pipe, probably some small diameter thick wall quality steel tubing..).

Either way, it's going to involve welding that needs to be done pretty well if it is to secure suspension and steering components.

Mike H.

[simplyconnected]

Mike explained it well... Imagine, you have millions of frames to make, all of which have a steering box and other supports for bracketry. These frames are pressed in two pieces for the front left side, two pieces for the front right, and the same for rear end sides. That's eight halves with torque boxes and side rails between the front and rear sub-frames, all welded together.

The front sub-frame includes clearance holes for the steering box. The rear sub-frame has clearance holes for spring mounting and an inside reinforcement around the arch. Mounting bolts must NEVER come loose so any through-holes need inside reinforcements to prevent the frame from crushing.

Ford uses presses with progressive dies fed with a coil of heavy steel. The dies trim and form flat steel into what we call a 'curly-cue' with spot weld tabs. This single part is exact in width size. It wraps around each of the three steering box bolt holes when spot welded into one half of the frame rail. When both halves of the frame are together you can hardly tell the curly-cue is inside. (In fact, QC destroyed many frames that were missing this important detail.)

Once inside the frame, the curly cue is simply a spacer that prevents the frame sides from crushing under thousands of pounds of bolt pressure. Yes, three pipes could do the same job but installing them is far too expensive in terms of weight, steel cost and fabrication cost.

I have welded pipes inside #1 crossmember, for upper 'A' arm mountings. The pipe ends are always exposed to the outside so it's important to use large flat washers that cover the pipe welds when finished. Using curly-cues, the spacer is totally inside the frame holes so large washers are not needed.

Frame assembly: Ford edge-trims strategic places on one frame half. The other half gets 'eyelids' pierced into the corresponding locations on the frame sides. When both halves are squeezed together, the trimmed edge of inner half stops at the eyelid of the outer half (for positive location). Then, this assembly is clamped and welded along the seam. I skipped an important step, which is to make sure all the inside details were spot welded inside (like the curly-cue and 'boot supports') before both sides are married.

The 1958 Squarebird (with rear coil springs) uses a nut, welded inside the frame sides for mounting the upper control arms. There is a Ford service bulletin that covers the replacement when this nut tears out. It's a design flaw that never should have happened. 1959 and 1960 Squarebirds do not have this condition because Ford quickly reverted to leaf springs.

A curly-cue inside the frame halves would have eliminated this condition. Problems like this appear when an outside vendor (Budd) designs and builds your product. - Dave

[bygrace]

frame thru-bolts

OK. I get it. Curly-cues. Thanks.
I was hoping for a better idea than my method of welding in tubes like you said, where a frame thru-bolt is needed. Your curly-cue reference sounded like it might be something I haven't thot of. Like I said, the bolt-in rear sway bar is under my consideration. Thanks, Mike S.

[simplyconnected]

I also have cars I will put rear sway bars into. Let's do a 'what if'...

Normally, at least one side of the frame is accessible. Let's say we use bolts that are 3/8" or .375" in diameter.

3/8" iron pipe is .675" OD and the hole is .493"

Conveniently, a 3/4" (.75") hole saw would be a perfect fit for the pipe, with .075" of clearance or .0375" all the way around the pipe (a perfect gap for MIG or stick welding). Use a bolt and nut to hold the pipe in place for tack welding.

You don't need or want the pipe welded on both frame sides. The purpose of the pipe is to prevent the frame sides from collapsing under bolt pressure. That means, you can make a clearance hole of 3/8" on BOTH sides, then open just one side with the hole saw, clamp the pipe in place, weld and grind it flush. The pipe would be a spacer with plenty of wall thickness to hold both frame sides apart and allow as much torque on the bolt as you want.

If you want a tighter bolt hole, after the pipe is welded in place, tack weld a 3/8" washer to the pipe-end of the frame. Done deal. - Dave

[bygrace]

Sounds like a plan. Pretty much what I did for the rack. Except I only welded one side, the flush side was just clamped in when bolted up. Might do both for the sway bar...
Thanks

[Mike Wright]

I think everyone should do with their car what makes them happy, whether it be all original, restomod, or whatever. I like the time capsule effect of being behind the wheel, so prefer to keep the appearance of the original column, steering wheel and shifter.

If I used an aftermarket column, it might make the steering linkage easier to connect and tilt would be nice, but I think I prefer leaving the key in the dash. How did you adapt the TBird wheel to the GM column?

What is under the hood, steering and brakes doesn't diminish the "time capsule" effect for me, though I know it does for others. Buddy I used to work with is a "numbers matching" kind of guy, but that doesn't mean very much to me.

I have a relatively new B&M Starshifter on the shelf and an extra 1959 console, but I prefer to leave it mostly stock-appearing from the driver seat. On the exterior, I will definitely use aftermarket wheels, but leave the rest otherwise stock-appearing. Do like the color of Greg's car, but will probably leave mine the original white for now anyway.

If you are working with Ford expansion tank and GM type HEI distributor (aftermarket?), 700R4 transmission, I am guessing you have adapted the GM OD transmission to the Ford motor? Aftermarket conversion bellhousing? Any tunnel mod's required? Special flex plate and starter?

Yeah Ford doesn't make it easy to put in an OD automatic transmission unless you have a later small block, IDT... But, for the cost of converting you can buy a whole lot of gas and with my stock 3.10:1 rear gear, it shouldn't be too bad RPM-wise on the open highway, or too sluggish on takeoff with BB torque advantage. Figure I will start with the stock 3.10 and if it is too high, I have 3:30(?), 3:55 and 3:70 9 inch 28 spline differentials that I could swap in - if it seems like a better idea later on.

I have read articles about Borgerson conversions installed in mid-fifties Fords and seen ads for them. I used to be concerned that the R&P conversions weren't heavy duty enough for a full size car, but my pickup with R&P is 600-800 lbs heavier with an empty box than the TBird, so recently have lost my aversion to considering using them.

Thanks, Mike

One aggravating problem I found with the Borgerson mod was I had to grind 1/8-1/4 off of the manifold on the drivers side. ( this will be corrected later when i pull the engine. ( I plan to "Z" the frame and box it in . Thus moving the steering box farther away from the engine. Who knows by then I may have acquired an High horse COBRA engine. I had the 700R4 built to with stand 600 HP.

We have found that using end fed Rack and Pinion can lead to "Bump Steering) so would recommend using a center fed rack.

I did a trick on the GM upper column. Measured and cut the upper part of the TB steering shaft. Then cut off the splinted part of the Upper GM shaft. Had a machinist drill the GM shaft for a near press fit with the TB shaft. Pressed it in and "cross drilled" and drove in "Roll pins"

There is an adapter available to use the AOD. Made by the same company that makes the 700R4 adapter. The advantage of the GM 700R4 is Lower gearing in first gear. The plans are iin to change the rear end to a ratio around 3.73 this will give an engine RPM of around 1700 RPM at 55 in OD. With the 3.10 on highway at 55 engine RPM should be approaching 2500RPM. In addition with the 700R4 you have a 4 speed transmission. and a blistering take off. Now looking at a currie differential from Summit.(~~ $1450 and it's positract) In have the Currie 3.83 on order, have the new axel brgs to install when I remove the 3.10..