Project: 1939 Jaguar SS100 Replica Classic Roadsters, LTD. "Duke"

[Cadillac Jim]

I ran across this article "Leaf Springs: Why the Hell Do We Still Use Them?"

http://www.web2carz.com/autos/car-tech/2252/leaf-springs-why-the-hell-do-we-still-use-them?w2caf=298c9c9f53282a30

The tech details are a little shaky here and there but the main points about the strengths and weaknesses of leaf springs are right on. In particular, when weight is at a premium, as in the Duke, the leaf spring still has a place in a high-performance rear suspension. The right design can give you high performance in the rear suspension of a light street car.

[Bruce Nunnally]

Interesting; thanks for the link. Looking at the rear we have both a shock with helper coil spring and the leaf springs. I asked Wylie Vintage Garage what they thought about just going coil-over and

losing the rear leaf spring; they suggested that the ride would be better if we restored the leafs and lose the helper spring on the shock. That's my goal for now is restore what is there.

In terms of authenticity, the original Jaguar SS100 suspension was on half-elliptical springs all round with rigid axles. The previous saloon model on which the SS100 was based had an innovative

rear end with the leaf springs outside the ladder frame, allowing the car to sit lower.

[Cadillac Jim]

I thoroughly agree with Wylie there. The spring rate on each wheel is one of the main things that determines compliance at that wheel. Too little compliance and that axle will tend to lose traction and swing out on high g cornering. You keep the compliance up and the lean down by controlling the horizontal roll axis relative to the center of gravity. When you have compliance to give away, you can add a stabilizer bar and get better improvement of the handling than simply increasing the spring rate.

I'm assuming that you have a regular live axle leaf spring rear suspension, like an Austin Healy 3000 or Fiat 128 or something. Features that may be helpful in understanding the rear suspension include torque tube (solid tube around the drive shaft that takes torque from the differential and applies it back to the transmission and engine), trailing arms, and a Panhard rod (or Watt's Linkage, a double-sided Panhard rod). If it has any of these things, it makes a difference on the stresses absorbed by the springs and the spring design. Trailing links absorb the torque and thrust of the drive forces and allow softer springs, and also control spring wrap and wheel hop, and those may be worth adding if you get a lot of torque out of the motor in the future. These can be bolted or welded on later. A Panhard rod or Watt's linkage absorbs lateral forces and allows for smaller spring shackles. A torque tube prevents lifting one rear wheel at high torque, a problem I had with my 1964 Chevrolet station wagon with live axle, coil springs, and Panhard rod. That was one strange station wagon.

[Bruce Nunnally]

Got over to Car Care Central in Plano for alignment, but they pointed out one last bushing set for the front -- the front strut rod bushings,

and the rear suspension needs to be all redone before it can be effectively aligned. Although it has a solid axle rear, with the

wear in the leaf spring bushings and saddle plate as soon as one would back off the alignment lift it might be out again.

On to the more restoration...

[Cadillac Jim]

That the rear springs must be fixed before the car can be aligned tells me that the rear springs are doing it all, like the Austin Healy 3000 and Fiat 128, as expected. The spring shackles, U-bolts and bushings are active suspension elements and stress points. All the more reason to get them repaired at a knowledgeable facility from the existing springs rather than buy new ones from dimensional specs.

[Bruce Nunnally]

Busy week but slow progress on the SS100.

Mechanic heading back over on Sunday to repair the bolts on the stabilizer bar bushing brackets, replace the front strut rod bushings.

He also wants to eval the rear suspension to see if dis-assembly and new bushings and hardware are all that are needed or if we truly need

new leaf springs. On the bright side should be easy to remove the left front bushing, since it is slipped out already.

Looking at the characteristics of the leaf springs they certainly look like Ford leaf springs, but they don't measure like any

I can find.

The ford shop manual for the 1980 cars arrived today to document the suspension.

I have added a photo album of Brochure images here: https://plus.google.com/photos/111669618335209044868/albums/5906981046139170321

I have a road trip planned for Friday in the STS-V, and the Spring shop is only open M-F, so an introductory trip & evaluation by the Spring

Shop is delayed pending evaluation and time.

[Bruce Nunnally]

Stock 3TC exhaust manifold with steering running along above it. Normally there is a heat shield over the manifold which I have removed for this photo.

The exhaust has a 2-bolt flange at the rear, and the new header has a 3-bolt flange. I am thinking do a test-fitting of the header to ensure everything clears,

then put the stock exhaust setup back on and take it back to Pronto Muffler for actual install and re-flanging.

Just eye-balling it and measuring it all looks like it will slot in, but we'll see.

Lower end of the exhaust manifold and run toward the rear. You can see the stock manifold is actually a "Tri-Y" for the inline 4, taking 2 cylinders into one pipe

twice, then bringing the two pipes together for the exhaust. So if the header can't be fitted then I will clean up and de-rust, re-paint the stock manifold.

[Cadillac Jim]

The stock manifold really doesn't look too bad, other than the channels right out of the head aren't straight and clean for an inch or two, and the four-to-two-to-one is tuning for bottom-end; your four-into-one is likely to have a set of peaks determined by the exhaust gases and the clearly uniform lengths of the pipes into the collector, and will likely give you a big torque peak around that RPM.

[Bruce Nunnally]

The SS100 stopped in traffic, but I was able to glide onto a side road and consider.  I cleared the fuel filter, and had good flow from the tank.  I called for starter fluid, but

the car would not catch with priming either.

 

 

Edwards' Mechanical came and helped (Thanks!).   No spark.  I had an extra distributor, so we swapped the rotor, no spark.  Swapped the cap, no spark. 

Swapped the distributor, no spark.  Checked the coil as bad.  Rechecked and verified bad. 

 

 

Replaced the coil from O'Reilly's.   Expected it to start, but no start still.  Retried starter fluid to ensure we know we had fuel but no catch.

Found a blown unmarked fuse under the dash, and shorted it, but no spark. 

 

The toyota system uses an igniter module that connects to the pickup on the distributor and communicates to the coil.

These cost $300 and have been discontinued. 

 

 

The MSD ignition module and Blaster coil perform the same / similar function and are less expensive.  We just got a new coil,

so perhaps just the ignition module.

 

 

More Sunday later in the afternoon -- we were already planning to work on the stabilizer bar and strut arm bushings, so

now we have new topics lol.  Towed the SS100 home and it is in the garage waiting on the next chapter.

 

 

Photo album: https://plus.google.com/photos/111669618335209044868/albums/5908057278729681969

[Bruce Nunnally]

Today I picked up some glass fuses to replace one fuse that was blown, and a new feeler gauge. I believe the fuse was tied

to the turn indicator circuit and not the ignition.

The 3TC distributor uses a hall effect pickup, which depends on an air gap of 0.008" - 0.016". I reassembled the ignition system,

took the distributor out, reset the air gap, cleaned off the distributor "teeth" and magnetic pickup tooth a bit, and reinstalled.

Still no spark but one more cause eliminated. I also ordered a new magnetic pickup just in case.

Our thinking is the igniter module is bad, and we are planning to replace with the MSD 6AL because the OEM part is no longer available

and because the MSD part costs less, works better, and is easier to replace in the future.

Spent some time with the multimeter checking to see if various ground spots for the engine were actually grounds, and if different

power points were clean power points. Everything checked ok there.

Edwards Mechanical to return this week to do the MSD install and wrap up the front suspension stabilizer bar and strut arm bushings,

then evaluate the rear suspension.

These are the markings on the rear differential. I suspect it is from an 81 Corolla, and so is a 6.38" 8 bolt Toyota T type

differential, but it is a mystery. I don't know what these marking mean. update: likely to be a 6.75" 8 bolt Ford. There appears to be a symbol in the middle of a

circle of 12 dots, an A in a circle, and a 3.

[Cadillac Jim]

The dial in a circle is probably a month indicator on when the housing was cast. Since the circle-A and the 3 are oriented differently, I have no idea which dot is January. I suspect that the 3 has to do with the year and the circle-A has to do with the type of housing or the OEM foundry name. Actual specific data would be embossed in like an engine number, not cast in, I would think.

I'm guessing. The dial with the pointer could be the year, and the 3 could be the month.

[Bruce Nunnally]

Could be. I was hoping they were an indication of what final drive is inside, but probably as you say.

[Bruce Nunnally]

I picked up the MSD 6AL fm O'Reilly's and it is in the passenger seat of the Roadster.

Should work with the pickup signal off the 3TC distributor and fire the stock coil in the Roadster.

Planned work for Wednesday includes:

• stabilizer bracket bolt repair & replacement
• reinstall stabilizer bar with new bushings, brackets, end links
• strut arm bushing hardware, install strut arm bushings on both sides
• install MSD 6AL ignition (& get Roadster running again)
• evaluate rear suspension for
  • update all fittings, bushings, hardware except the leaf springs
  • also replace the leaf springs

The more I think about it the more I think it will play out this way eventually--
update every bushing, plate, bolt except the leafs then decide if the leafs
have to also be replaced. So ideally we will come away Wednesday
with a complete parts list to order from and can schedule a day to tear into
the rear suspension.

Only pain is pressing the bushings in/out of the spring front eyes, and
old rusty bolts. I can start soaking the bolts for several days ahead of
planned suspension work.

Added a zoomable diagram of the rear parts to the album here
Most of the parts are generic but the diagram may help us get everything
in hand, and it has torque specs.

Also this reference image showing a tool used to remove / press out the leaf spring bushing

[Cadillac Jim]

The rear suspension design has come into focus for me. The short front legs of the springs are effectively trailing links, and the longer rear legs provide the springing action, and the two bushings provide lateral location. You don't need trailing links or a Panhard rod. This is an excellent simple configuration for a high performance suspension for a light car that does not require long suspension travel. It also tells me why one spring bushing can cause wrap-up on acceleration and such. The rear springs may be custom for the Duke to give better control and higher performance than you would want or expect with the Ford compacts.

The 1953-1962 Corvette shared front suspension parts with the 1949-1952 Chevrolet. In the front suspension, the A-frames, kingpins, and spindles were the same (the spindles may have changed with later models) but the mounting points, springs and stabilizers moved the roll axis to make the C1 Corvette a true sports car. Similar changes on the live axle rear suspension allowed high performance for the day. But, yes, the 1962 Corvette has kingpins, not ball joints.

[Bruce Nunnally]

Roadster Rear suspension:

Got a quote from suspension king for all the leaf spring parts:

I requested they quote a 80 Pinto for following parts; (I also wanted to know if I was missing any parts for a refresh):

2 front eye bolts

2 front eye nuts

2 front eye bushings

4 u-bolts

8 u-bolt nuts

2 sets top/bottom leaf isolators (Ford 5732 equivalent)

2 bump stops

2 leaf spring center bolts & nuts

4 rear leaf eye bushings

2 complete rear shackle kits

Quote:

TheSuspensionKing.com

Jason E. Valant
Keystone Spring Service
2061 New Castle Road Portersville, PA 16051 USA

JValant720@aol.com

Springs = 215.00 each 430.00 total

front bolts w/ nuts = 3.775 total 7.50

ubolts w n&w = 8.00 each 32.00 total

bump stops n/a

centerbolts will be installed in springs...

2 shackle kits with bushings 20.00 ea. 40.00 total

4 insulators MFRI6 9.00 ea. 36.00 total

Shipping 83.97 TOTAL

PARTS & SHIPPING : 629.47

So without the springs plus with the bushings which he assumed are in the springs, about $200 delivered.

He may have meant, "Hey, let's just make the springs up custom for you like Pinto springs but 6" shorter",

which could be a good point. I sent back a note but probably need to call and chat.

Could skimp on the shackles but seems clean and easy to just replace the hardware.

The insulators are rubber pads below/above the leaf springs in OEM design.

The center bolts are just grade 8 bolts so can source locally.

After we measure, photo springs if they have to be remade we can send them specs and they can mail springs. U-bolts are non-reusable due to stretch but small waste.

[Bruce Nunnally]

The rear suspension design has come into focus for me. The short front legs of the springs are effectively trailing links, and the longer rear legs provide the springing action, and the two bushings provide lateral location. You don't need trailing links or a Panhard rod. This is an excellent simple configuration for a high performance suspension for a light car that does not require long suspension travel. It also tells me why one spring bushing can cause wrap-up on acceleration and such. The rear springs may be custom for the Duke to give better control and higher performance than you would want or expect with the Ford compacts.

The 1953-1962 Corvette shared front suspension parts with the 1949-1952 Chevrolet. In the front suspension, the A-frames, kingpins, and spindles were the same (the spindles may have changed with later models) but the mounting points, springs and stabilizers moved the roll axis to make the C1 Corvette a true sports car. Similar changes on the live axle rear suspension allowed high performance for the day. But, yes, the 1962 Corvette has kingpins, not ball joints.

I am certain I have made this process harder than it has to be -- mostly because I am interested in what is there, why it is there, etc.

The Roadster is a bit of a puzzle, but if one of the local spring shops still in existence were closer we'd be done by now and on

to the next restoration item.

[Bruce Nunnally]

New Ignition install album: https://plus.google.com/u/0/photos/111669618335209044868/albums/5909614090620501169

Thanks to Edward's Mechanical the MSD unit is installed.

Hand testing fit of the MSD unit behind the battery

Lots of wiring harness, connectors, and pony tails to use to rapidly get the right connections

View of the MSD on the firewall behind the battery, battery removed

Another view. Install went okay, except tach is not working -- we need a tach adapter which should be here tomorrow.

Also, the blower motor control module appears to have been leaking, which may be why the radiator fans run all the time.

We removed it and will plan to replace when the fans get replaced.

Fired, re-timed, and ready for a test drive. hmm, the headlights stopped working, so that took some diagnosis time in the driveway.

Test drive went well and the car is running well.

Looked at the rear suspension and considering the options.

Rescheduled for the front strut bars and stabilizer bar issues for Saturday.

This photo struck me as artistic: View looking rearward into the reflection of the front of the car in the wind wing

Bburago scale model:

BBurago 18:1 scale model of the Jaguar SS100. A model of an English car made in Italy.

Nice detail: the wheels are actually held on by the center caps 'spinners', and are removable. The bonnet strap opens, as does the bonnet, to reveal a model of the 2.5L straight six. The 72 spoke wheels are well done, and the spinners have SS's on them. The windshield glass shows the smaller faring windshields for when the main windshield was folded down.

Missing? canvas top. The rear shelf looks a bit too much like a rear seat for the 2-seater.

This looks like my Roadster, except mine cream on burgandy instead of white on black, has twin side-mount spares instead of single rear-mount, and mine is 1:1 scale.

[Bruce Nunnally]

Tonight the Roadster had a new symptom -- because the radiator fan controller failed back in history sometime, the radiator fans run on key on. We'll fix that once we get to it. Further, headlights shorted out and blew their 20A fuse. Headlight high-beam indicator on all the time, key off or key on.

However, tonight no fans on key on. This coincidentally also meant no ignition signal / power to the MSD on key on. Only happened intermittently -- such as if you cranked it over twice, then the fans would start. But if you drove off, it might die. Or if you restarted, the fans might be offline again.

I proved this by backing out of the drive, and stranding the roadster in no-start condition in the street. Luckily after I pushed it back up hill into

the driveway a neighbor stopped by. They wanted to share that they had seen the Roadster, loved it, and wanted to make sure

I know they think it is a great looking car. I have time for that all day. Especially when the car won't run anyway.

Figured it was a short somewhere -- finally tracked it down to these two inline fuses under the dash.

First clue something is wrong here is inline fuses under the dash, in close proximity to a fuse panel where they are not.

A unrelated clue was I burned my arm on a nearby relay while investigating the inline fuses.

At first I assumed this was because I live in Texas and the metal steering was hot, but then I realized it

was the electrical components (which should not be hot).

Re-assembling the opaque fuse holder, which electrically re-connected the fans and the MSD unit, and the Roadster can start

and run.

Investigating the skin-burning component I pulled off an off little relay.

It was gummed up a bit with 30 years of being an odd little can relay.

I cleaned it off, and carefully straightened out the wires going into it

and re-installed it. Now the previously not working hazard lights work.

Finally, the headlights are still buzzing (by which I mean that the headlight fuse is screaming that it is

about to blow and so I turn off the headlights) and has a short, and the headlight highbeam indicator

is glowing all the time, even key off -- suggesting a short. Off to think about those next / soon.

Edwards Mechanical due back tomorrow afternoon to work on the suspension and trim up the

MSD install. Hopefully I can start fixing more of these side-tasks.

[Bruce Nunnally]

Spent the day on electrical system. Fixed the headlight issue and a new issue with horns.

Rebuilt the headlight switch by cannibalizing a new switch.

Replaced the front headlights and 2 of 3 relays. At the end of the day car running

with no shorts and functioning fans, msd, headlights, horn.

Edwards Mechanical here now and has installed the MSD tach adapter,

So the tach is back working. That started a side trip on calibrating the

carb linkage to be more smooth.

Next we still plan to reinstall stabilizer bar and strut arm bushings tonight.

Then I will need to start driving the Roadster more and check out prior

To taking it downtown Dallas to the spring shop for rear leaf springs.

[Texas Jim]

Everything seems to be finally coming together...

[Bruce Nunnally]

Side track got us side-tracked. Car was running unevenly, (perhaps in hindsight due to low voltage). Updating the timing

did not have the expected effect.

The battery started chugging down. This led to consideration of the alternator. That led

us to the discovery / realization that what we thought was the melted / dysfunctional radiator fan control module was actually

the melted / dysfunctional alternator external voltage regulator. It helpfully is a large non-descript control module with

only the manufacturer's name and Made in Hong Kong on it, but now that we know what it might be it matches the pics of

the replacements.

That is a horse of a different color, and needs fixing right away.

This from a 1980 (not 1981) Toyota Corolla. Luckily these appear to be readily available.

The crew at O'Reilly's has been helpful through the restoration.

We have rescheduled the alternator regulator update and front suspension work for Sunday afternoon.

[Cadillac Jim]

All those electrical problems - are they making you homesick for GM???

[Bruce Nunnally]

I do miss modern OBDII computer info, which diagnoses and often tells you in plain English what the issue is.

Part of the zen of enjoying old cars is learning the car -- knowing that when you get this symptom, it means that you have 'that' problem.

Acquiring an as-is project like this means that I am getting a crash-course in what is normal for this car. The fact that the car itself is a

parts-bin puzzle from multiple manufacturers further modified or updated by multiple owners complicates understanding.

In each case we are attempting to restore the car to as or more reliable than it was originally. Some of the issues I am

addressing are a consequence of being 30+ years old. Some are a consequence of having sat for 7 years. Some are a

consequence of poor choices during manufacture or modification.

This is a simple car, is relatively easy to work on, and has relatively few systems. No A/C, no emissions, no power anything.

Engine, transmission, brakes, electrical system, cooling system, suspension. Because I am restoring it to own & enjoy,

I keep trying to remind myself that this is a marathon and not a sprint, so no need to try to get everything done at once.

But to enjoy the car we need it to be safe and reliable, so we are focusing on that.

[Cadillac Jim]

Yes, an old car has simple subsystems that can be repaired by hand. I overhauled the alternator on my 1969 Chevrolet once, etc. when the bearings got noisy, and Ive told funny stories about dropping an aircraft bolt through the hub of an extra wheel that I was using to support a scissor jack for holding the engine up when changing the front motor supports.. But I was thinking of the electrical systems on cars of that vintage, circa 1980. I traded my 1977 Malibu for a new 1986 Ford Escort that I drove until I was t-boned in it in 1989.

I discovered that the electric fans would go two years in L.A. where the A/C kept them on all the time and sitting in traffic on IH 405 was its normal habitat, and that the motors weren't serviceable and didn't come separately from the fans, so I bought a set of fans every two years and put them in myself. I bought a of relay once too but I'm not sure that it needed one. I never bought fans or relays for the Grand Am in the seven years that I drove it in L.A. or the ETC in the 15 years I drove it, including the first four years in L.A.. Also, the alternator light would occasionally come on for anywhere from a second or two to as long as the car was moving every few months, only when the battery was fully charged, which apparently was due to something happening in the regulator inside the alternator; the dealer couldn't reproduce it. It had no effect on the alternator keeping the charging voltage at 14 Volts to 14.5 Volts. Eventually it dawned upon me that they all did that and nobody had a fix, but it was just a cosmetic problem so nobody cared. Perhaps a new (updated) alternator would have fixed it but that was very expensive for a rare cosmetic problem.

I've driven a lot of GM cars for a lot of years. I've had two starters, a couple of alternators, and a generator and regulator every year or two back when cars had generators and external electromechanical voltage regulators, and that's about it insofar as electrical problems are concerned, not counting bulbs.

I've noticed that my 2011 CTS-V is far simpler than my 1997 ETC. You look up a schematic, and everything electrical hooks to a module, a switch or fuse or relay, or ground. All the schematics are very simple.

My only gripe is that they still haven't figured out hot to use GPS time to keep the clock time; all they would have to do is let the GPS time correct the clock to 30-minute increments because there is no time zone in the world that uses GMT plus or minus anything else except Nepal (UTC+5:45) and New Zealand's Chatham Islands (UTC+12:45), and you could use a setup bit for export models to allow for 15-minute jumps. Then, setting the clock would involve 30-minute (or, in Nepal or the Chatham Islands, 15-minute) jumps when you pushed the buttons, not 1-minute jumps. Some smartphone apps switch time zones when you cross from one time zone to another with the phone. If they can do that, why can't a Cadillac? Smartphones also adjust the difference between magnetic and true North automatically. But, the compass zones are still set manually in Cadillacs; if the GPS knows latitude and longitude, and the compass magnetic North correction zones are in the owner's manual, why can't the car's computer set the compass zones?

[Texas Jim]

My only gripe is that they still haven't figured out hot to use GPS time to keep the clock time; all they would have to do is let the GPS time correct the clock to 30-minute increments because there is no time zone in the world that uses GMT plus or minus anything else except Nepal (UTC+5:45) and New Zealand's Chatham Islands (UTC+12:45), and you could use a setup bit for export models to allow for 15-minute jumps.

Then, setting the clock would involve 30-minute (or, in Nepal or the Chatham Islands, 15-minute) jumps when you pushed the buttons, not 1-minute jumps. Some smartphone apps switch time zones when you cross from one time zone to another with the phone.

If they can do that, why can't a Cadillac?

Smartphones also adjust the difference between magnetic and true North automatically. But, the compass zones are still set manually in Cadillacs; if the GPS knows latitude and longitude, and the compass magnetic North correction zones are in the owner's manual, why can't the car's computer set the compass zones?

I have wondered that for a long time...

It seems to me, that it would be a pretty simple process to do.

My phone adjusts the time automagically whenever I cross a time zone.

On the Cadillac.... I have to manually advance the clocks... (the digital one in the NAV / radio and the analog one in the dash)... one hour if I am going east or ELEVEN HOURS for the analog one in the dash and back up the digital clock one hour, if I am going west, every time I cross a time zone.

One other small gripe about phones... if you are talking when you cross a state line... about half the time it will drop the connection.

I talk to two of my brothers a lot, who are long distance truck drivers.

The dropped connection when crossing state lines if pretty common.