by Jim Morrison

After rebuilding my front suspension, I installed a set of the CAT Club 335 pound competition front springs. The front-end ride height was greatly increased from stock and looked funny, too. I decided to cut off the springs to lower the car by 55mm to my desired height (slightly lower than the stock height).

Now the problem was “How much to cut off the springs?”

I came up with two methods (one courtesy of Jim Burruss here in Huntsville and one of my own doing). Fortunately, they matched very closely. Here they are:

Jim Burruss’s way was to measure the distance between a point on the upper portion of the cross member and the A-arm at points directly forward of the centerline of the spring (i.e. points that are the same distance from the lower A-arm pivot point as the center of the spring). This measurement is made at the ride height with the new springs installed (in my case this was 103mm) and again with the springs removed using a floor jack to adjust the ride height to the desired level (resulting in an 81mm measurement in my case).

The actual points you use are not relevant, only the difference in the two measurements. Don’t forget to have the spring insulators installed for these measurements. The difference in the two measurements was 22mm. This is the amount to lower the height of the springs.

My method is a little more complicated. I measured the distance from the A-arm pivot to the center of the spring along the A-arm (185mm) and the distance from the A-arm pivot to the hub face (that the wheel fits against), which was 483mm.

To calculate the amount to lower the spring height, I then multiplied the amount I wanted to lower the ride height (55mm) by the ratio of the two measurements above resulting in: 55mm X 185mm / 483mm = 21mm.

Both techniques assume that a change in the freestanding spring height results in the same change in the compressed spring height. While not strictly true, the relationships very close to linear for the relatively small changes needed.

To mark the spring for cutting, set the spring vertically on a flat surface and measure the free height of the spring. Subtract from this the amount to lower the spring height calculated above, resulting in the desired spring height.

Measure up from the bottom of the spring to the desired spring height. Find the point on the top of one of the coils that corresponds to this height and mark it.

Now move up the spring one-half coil (one half turn) higher than the mark. This is the point to cut the spring. A torch or band saw should do it (I took mine to a machine shop for this). While you are there, have them bend that last half coil on top down (bending at the desired spring height mark until the top end touches the coil below it) to provide a fairly flat surface for the top of the spring.

Either procedure is not exacting, but I did get my ride height to within 4mm of my desired height. Some fine-tuning can be done by using different spring insulators.

One type (I believe this is the original style and is sold by the CAT Club) is approximately 0.6 inches high and fits on top of and outside of the coil.

The other style is like that used on a 1974 Mustang II (Ford part number D4AA-5415-A). It is about 0.25 inches thick and fits on top of and inside the coil. Replacing the Mustang II unit with the CAT unit increased my ride height about 0.5 inches to compensate for some spring sag since installation. I have even heard of some Tiger owners using the spring insulators on the top and on the bottom of the springs. While not designed to be that way, I have not heard of any problems doing this.

Editors Note: For the proper ratio of the lower arm, the distance from the A-arm pivot to the lower ball join should be used instead of to the hub face. If the spring is cut with a torch, shield the spring so that sparks cannot damage the wire surface.

by anonymous

Question:

Does the Tiger have any “weak” points that will come to light with increased horsepower? For example, I have heard that rear spring mountings are weak and will break under stress.

Answer:

In preparing a Tiger for autocross or just for safety’s sake for street use, the front cross member welds should be reinforced, particularly around the shock towers. The CAT shop notes do a very good job of outlining these points to be reinforced. The reinforcement of all welds on the suspension mounting points is a good idea. These can fatigue and fracture over the years. It is also a good idea to reinforce the frame cross member around and underneath the openings for the Tiger exhaust pipes by welding 5/32″ thick plates to the three sides of the frame box. Cutout cardboard templates were required because it is a tricky geometry problem to get the plates the right shape.

Perhaps this has happened to you:

You’re at a local autocross, it’s the last run, you have to make up .5 of a second to win your class, and finally beat the son-of-a-Z car that’s been giving you trouble all season long. You are doing just great until you give a little too much power in a long sweeping turn and before you say, “Buddy, send your rice grinder back to Japan”, your rear end is now where your front end was and you’ve knocked over 20 pylons.

You ask yourself, “What can I do to correct this shameful act?” Well, you could sell your car, or just plain quit autocrossing, but if you’re anything like me you can’t buy either of those alternatives.

You could continue in this shameful manner and plug your ears when they taunt, “Sunbeams never were meant to have a V-8 in them!” or “Take that thing to the dragstrip where it belongs!”

But nooo… there must be something else to do. A good rear sway bar set-up is the answer. An Addco bar is as good as any.

Right out of the box, if you follow all the instructions, your rear sway bar will really improve the car’s handling. Unfortunately, it only works for a short period of time. The center rubber bushings will become stretched so badly that the bar will barely work at all. The bar’s end mounting will also work itself loose.

If you constantly want to crawl under the car and tighten up the sway bar bolts, it will continue to work okay. But if you really want to show that Z-car that your Tiger gets meaner with age, you will have to do a little work.

The center rubber bushings must be changed to DELRON. This particular bushing will have to be a two-piece bushing, in other words, it will be cut in half so it will fit over the bar. The best thing to do with the stock ADDCO end brackets is to take them in your hand … and drop them in the nearest garbage can. A new end bracket will have to be made. My end bracket is made out of 1/4″ steel plate. It has a pivot and is adjustable.

The sway bar should be put on with the end arms facing the rear and the bar should remain level when installed. The bracket should also be bolted through the frame or welded to it. (Bolts with sway bar kit will pull through frame).

You will be glad you went through the extra trouble if you plan to install a rear sway bar. With the right amount of pedal pressure, your old Tiger should be able to slide through the comers with a slight over steer.

Autocross Check-Up:

Be sure to check for loose nuts and bolts on leaf springs, traction bars, panhard rod, and sway bars. Check for stress cracks in frame in these areas: where traction bars weld to frame, where lower A-arm bolts to cross member and check cross member itself. Make sure front sway bar brackets are solidly in place. Check all lug nuts to make sure they’re tight. Also check your motor mounts; no one wants their water pumped through their radiator.

by Burtis S. Homer

A potentially dangerous condition has come to my attention on two occasions. It is quite probable that this defect exists on other cars also. A thick steel ring into which the upper ball joints are pressed had broken away from the stamped steel portion of the upper A-arm. This ring is only spot-welded on originally. This ring should be welded on as completely as possible, front and rear. This can be done on the car by freeing the upper ball joint from the stub axle carrier and pushing up as far as possible. Also, the flat wire upper ball joint retainer has been found to be missing on some cars. This can lead to the ball joint coming free of the control arms. This wire retainer can be replaced with a 175 outside snap ring, which is much better.

by Jim Anderson

Tiger Tales, the newsletter of the California Association of Tiger Owners, carried a rather disturbing editorial, entitled “Time Bomb!”. Written by Herb Mosley, the newsletter’s technical editor, the article begins: “Every Tiger on the road with an unreinforced crossmember is a time bomb waiting to go off “. Until this critical assembly is strengthened, your Tiger is at least as dangerous as the Pintos with the exploding gas tanks or the Buicks with the floppy engine mounts, if not more so”.

Mosley follows this dramatic warning with the explanation that the sheet metal assembly, although well engineered for the original purpose of holding up the front end of an Alpine at normal speeds, was weakened to accommodate the steering rack of the Tiger.

The villain, says Mosley, is the constant flexing and vibrations, which weakens the metal and the welds. “At some point, it will come apart”. It seems that this has happened to one California member. He says the problem is preventable by having some weak points reinforced by a welder at a cost of about $50, once the assembly is out of the car.

We checked with two of our East Coast technical experts, Tom Calvert and Bob Rhodes, and the sum total of their advice is that the situation is not quite as bad or dramatic as Mosley paints, although it does exist.

Tom Calvert said, “In cars with sticky race tires, it is something that people should look for, especially if they autocross or race, and put more load on the assembly”. “Typically, it’s the cars with the stiffer springs and the fatter tires which have failures.”

Bob Rhodes, who has more than 200,000 miles on the current crossmember in his Tiger Mark Il (complete with fat tires) and who has autocrossed with a great deal of success, says, “The assembly was over-engineered for the Alpine, which was good”. If there is a weak point, says Bob, it would be at the shock towers and that could be reinforced by a weld that would not require removing the assembly. Just taking a wheel off would do. If a crossmember would go, the effect would depend on which part let go. The case reported by Mosley in California was able to steer to a safe stop.

Editor’s Note: This article was reprinted to reflect a typical owner reaction to an article published in many marque newsletters which predicted doom, gloom and instant life threatening hazards caused by Tiger crossmembers. The truth lies somewhere in the middle.

Any vehicle 35+ years old should have its suspension integrity verified. It is true, Tiger crossmembers do experience stress cracks, sag and break at the shock towers. But it is not epidemic proportions. There is always a risk of mechanical failure in any vehicle which can be life threatening. The Tiger crossmember possesses a higher risk. Therefore, have its integrity verified by a competent Alpine/Tiger specialist. If an inspector is not aware of this problem then find one who is.

Another Shocking Story

by Dave Johnson

Finding shocks to fit the Tiger or Alpine is getting more difficult.

The original Armstrong Heavy Duty Shock had the following dimensions:

• Extended Length 12″
• Collapsed Length 8″
• Top fitting stud
• Bottom fitting 1 1/2″ ring with 3/8″ bushing sleeve
• No Dust Cover

There have been several shocks listed by other tech tips that can be modified to fit. I found that the Monroe GasMatic shock 5824 fits the specs with the exception that the sleeve is 2 1/4″ long with a 7/16″ bolthole.

I tried cutting the sleeve but found that it was made of hardened steel. Even if I could cut it, I would still have to enlarge the hole in the mounting bracket from 7/16″ to 3/8″.

Using appropriate size sockets, and a vise, press the old sleeve out of the old shock. A 1/2” inch pipe ‘T’ fitting was just the right thing to press the old sleeve into. It held the bushing in place but allowed the sleeve to be pressed out.

Using the same sockets, vise, and pipe fitting, slowly press the new sleeve out of the new shock. I used silicone spray to lube the sleeve as I pressed. I would press forward about 1/2″ and then release the pressure on the bushing. By looking into the pipe’s hole you can watch your progress. Stop when the new sleeve is just starting in the new bushing (about 1/16″). Switch from the socket to the old sleeve and continue pressing the new sleeve out. It won’t take long until you will have replaced the wrong size sleeve with the correct size old sleeve. Your shock is now ready to mount using the original bolts and bracket.

The trick is to use the old sleeve to push the new sleeve out. If you push the new sleeve out first, the hole in the bushing will collapse to about 1/4″. You’ll never get the old sleeve in the new bushing without tearing it.

FURTHER NOTE: If you have an emotional attachment to the original Armstrongs and don’t want to remove the sleeve, most auto parts will carry a 7/16″ by 1 1/2″ sleeve. But you’ll have to enlarge the mounting hole and use a 7/16″ bolt.

Editors note: The latest Monroe Gas-charged shock absorber that I have found that matches these dimensions is Part # 20814 and are called “GasMatic GT”. These shocks were originally designed for the Ford Pinto and Mustang II and may be sold under many other names.

First printed 4/87

What shock will fit on the Alpine/Tiger (as compared to other cars)?

Your best bet is to buy a set of Konis or Spax for the Tiger from one of the
Sunbeam parts houses. Although expensive, you can be sure they are going to bolt right on.

The Gabriel “Adjustable E” models are also a good choice (model 63329 or 63170 for the front and model 63331 or 63171 for the rear). If you want to try a less expensive solution, some cross-reference info is presented here. I can’t vouch for the accuracy of these but they should be a good starting point.

With some of these shocks, it will be necessary to use different mounting bushings and/or bolts than supplied.

First printed Reprinted in 7/87

Does anyone make a gas-filed shock for the rear end of my Tiger?

Yes, but they will not admit it. One club member called KYB for one of their Gas-a-just shocks. They said they do not make a shock for Tigers.

Order shock # KG5536 for a Capri.

by Barry Schonberger with Bob Jardine and Tom Patton

In 1975 STOA reprinted an article by L.C. (Bud) Bohrer, the 1974 SCCA Solo II “B” Prepared National Champion on “How to Autocross a Prepared Tiger.” To this day, that article (see attached) remains an excellent reference for preparing a Tiger. In the 14 years since that article was published, SCCA Solo II rules have changed considerably (they even let us run tube frame cars), so a few comments are in order. My reference points for this article are two MK I A’s and an MK II that have won consecutive Divisional Championships in competitive SCCA Divisions and one SCCA National Championship. Preparing a car is like climbing Mt. Everest; the goal is to get to the top, but there can be a wide variety of successful paths taken to get there.

Suspension

Start here before you invest big dollars in your engine. All of the power that money can buy won’t get you around the course unless you can get the power to the ground and make the car handle. Starting with the front end, don’t hesitate for a minute to reinforce and rebuild the cross member as to the specs in Tom Hall’s and Torn Ehrhart’s tech tips. The stress that the front of the car will take when you bolt on race rubber is well beyond the original design. Pay special attention to the welds around the shock tower and A arm bushing sleeves. Check the threaded plates where the lower A arm attaches. Don’t hesitate to tack weld the upper ball joints in place. Also, you must reinforce the sway bar clamp bracket slot in the lower arm. (Tom Patton failed to defend a Divisional Championship one year because of this failure). A strip of metal welded across the top will do the job. All inner A arm bushings should be replaced with a solid material impregnated with a lubricant. The solid bushings give the driver a much better feel for the road and eliminate the suspension settings changing as a result of the rubber bushing flexing. ‘The upper A arms may be lowered at the shock tower to obtain an improved roll center and improved camber gain. A 1″ solid or preferably hollow front sway bar set in solid bushings seems to do the job. I would recommend Koni shocks on the front set full hard. Because of the front wheel spring rate on a Tiger, the springs need all the help they can get a spring rate of 250 lbs. and custom 70/30 shocks would be optimum.

Concerning front springs, I found the CAT replacement springs acceptable when used with the rubber seats. I have known people to run them without the rubber seats to lower the car. A hard to get item, but one that makes a world of difference, is a quick steer rack and pinion as offered by Bill Miller in the 70′s. This unit reduces the lock to lock from 3.2 to 2.6 turns, providing a real asset in Solo. (This rack is no longer produced). Front-end alignment was 1.5 degrees negative camber, 3.5 degrees castor and 1/16″ toe out. Toe out helped the car turn in faster.

Current Solo II rules allow 12″, 13 “, or 14″ x 10″ wheels or 14″, 15 “, 16″ x 8″ wheels. The only two wheel sizes that are even up for consideration are 13″ x 10″ or 15″ x 8″. The reason for that is the availability of race tires from the major manufacturers. The current situation is not good. The 13″ tires are still being developed, but not for cars in the Tiger’s weight class. Only two companies have 15″ tires available with a third possible in the future. However, limited development is taking place in this area. The big advantage of the 15 ” wheel is the possibility of running bigger brakes. If you choose that route, however, you will be considered a GT spec car, rather than production, and may have to run the 10% weight penalty (not a good idea with a production car). The best answer seems to be a 13″ tire, 9″ to 10.0″ tread face by 20″ or 21 ” tire circumference. This tire is available from a number of manufacturers. When considering wheel offset, remember the stock front suspension geometry win only accept a 3.5″ backspace before the rim hits the rack and pinion arm. Most applications are only 8″ rims in the front because of this clearance problem. With a 10″ front wheel the offset is to the outside, causing scrub problems because of the design of the spindle and Akerman angles. (Look for new rules allowing 16″ X 10″ wheels in 1992.)

The rear suspension can take on a number of different configurations. I found that the forward spring mount needed to be reinforced. It’s very common for this area to be rusted and cracked. I used the CAT springs in their hardest arrangement. Bob Jardine uses stock springs with additional clamps on the front half of the spring to prevent spring windup. I tried a number of different approaches to traction bars before I discarded all of them and went to Ford Mustang quad shocks. Talk about eliminating wheel hop and being able to launch a car, these babies do the job! Brackets were fabricated for the inside of the frame rails and the axle tubes. Credit for this application goes to Bill Miller, who was familiar with the use of shocks as a torque reaction device on the Hollywood car. The rear axle was raised in the chassis using 1 ” blocks at the spring pads. Blocks could be eliminated by de arching the rear springs. This, in relationship to the front ride height made the car just a hair higher in back. Under acceleration, the suspension would even out. A new panhard rod running from driver’s side to passenger side was fabricated to allow for rear roll center adjustment. A 3.73 LSD with the MKII wide ratio transmission allowed for the car to be driven in only 2nd gear on most courses. Shocks were Sprax Adjustable, set on three clicks or in Bob and Tom’s case, Koni’s set full soft. The softer setting allows the power to get to the ground. I didn’t install a rear sway bar. The car only pushed in tight off camber turns and I would compensate by braking deeper in those comers and getting the rear end to come around. Both Bob and Tom used a 5/8″ rear bar. Stock springs and a bar just might have the same roll stiffness as the CAT springs. Bob likes the stock springs with a 5/8″ bar, because it “gives me a little more compliance on the rear with rough surfaces.” I ran a disc brake conversion on the rear, and Bob ran the LAT disc option, but we’re not confident that it helped in the Solo application. My rear wheels were 13″ x 10″ with a 4″ backspace. The car did have Gremlin metal flares on all four comers.

Brakes

Use a soft street Datsun Z car pad. No metallic or semi metallic, because they don’t heat up fast enough. Datsun pads give you a little extra pad area. Braided brake lines with an adjustable brake bias in the rear line were installed. Bob kept his brake booster, because “It is a lot easier to modulate the brakes if you don’t have to stand on the pedal!!” Bob also suggests “looking at Datsun for rear wheel cylinders that are direct replacements for the Sunbeam, but of different diameters.”

Engine

With the new rules, you can run a 302 bored out .047″ over with any head. This appears to be the hot ticket in the Tiger vs. small block Corvette game. A number of Tiger owners have installed SVO aluminum heads with success. Other full comp heads could be a problem when it comes to headers. For Solo purposes, you want your torque range to be very broad, i.e. low duration, high lift and possibly a split profile. Unless you use a roller cam, it is difficult to get this profile. Big dollar item, but could make the car very drivable in one gear. As a starting point, I found the General Kinetics Co. “Redline” hydraulic cam with 290 Duration 438 lift strong (this area needs more discussion). Because of the RPM range involved and the torque needed, the Edelbrock Torker II with a 600CFM double pumper was used, and time was spent timing the carb (see reference book at end of article). A good electronic distributor with a computer ignition will do wonders in Solo because of the ability to keep the plugs from fouling. If you want to save a little weight on the front of the car, use an early timing cover with the exposed impeller aluminum water pump. A bigger radiator core is a must, along with an electric fan upfront and 6 blade behind. An electric water pump drive comes in handy also to cool things down between runs. You are very limited when it comes to headers. The lack of space is your problem. A set of headers from CAT or J.C. Whitney will do the job.

Don’t go too radical with your compression ratio if you intend to drive’ on the street. Ratios in the 10 to 1 range give you the power without excessive heat and octane problems. Compression does help torque however. Oil control in comers is a problem with the small block Ford. For Solo purposes, a Boss pan and windage tray will solve most problems. However, the investment in an Accusump system is recommended. For Solo, you might have your engine builder set the engine up with pretty wide main and rod clearances. You don’t get much of a chance to warm the oil, and the clearance helps. Bob recommends a good oil cooler to help in cooling.

Engine and Transmission Mounts

Drill an extra hole and add a 5/16″ bolt to the driver side mount. Weld up a solid mount on the passenger side. Bob says enlarging the plate on the tubular transmission mount can control wheel hop. This restricts the movement of the rubber mount.

Rear End

The Dana 44 rear end is plenty tough for Solo. The Power Lock LSD is as tough as they get with its four spider gears. You might consider shimming up the LSD so that the release pressure is higher. Use a gear lube additive to control clutch chatter.

Clutch

Quick acceleration and engine braking are important elements to a successful Solo car. For Solo II, a double or triple disk, racing clutch is essential. With its lightweight (18 21 lbs.) and small diameter (7 9 inches), the racing clutch will make a significant difference. McCleod makes one of the best, followed by RAM and Quarter Master. The down side of this clutch is its in/out characteristic. There is very little feel. Starts can be a problem, it is not streetable and for a Pro Solo launch, you lose the weight of the flywheel. Use a soft diaphragm spring if available with not too high a ratio.

You might also consider an internal throwout bearing slave cylinder. Manufactured by Tilton, QuarterMaster and others, this item has proven to do the trick. Alignment and spacing are critical in the setup. Certain models only work with certain clutches because of clutch finger design.

Fuel Supply

A good Carter, Holley, etc. fuel pump with a constant 5 – 6 lb. pressure is what you need. Install a good, large capacity fuel filter because the Tiger fuel tanks will peel their lining. If you’re in a hot climate, consider a cool can to chill your fuel. It can be located where the brake servo once lived. The stock metal fuel lines are acceptable.

For additional information, don’t hesitate to contact me.
Barry Schonberger
(812) 985 9592

Ed note:
Does anybody have a copy of this article by L.C. (Bud) Bohrer, the 1974 SCCA Solo II “B” Prepared National Champion on “How to Autocross a Prepared Tiger.”
Use the contact form and let us know. We’d love to be able to reprint it here.
Thanks

First printed 3/82

If you need front wheel bearings for your Tiger or Alpine and your local parts store doesn’t have a listing, get the bearings listed for 71-74 Capri. The Sunbeam grease seal is not the same. The following are BCA numbers for Tigers and Alpines.

Inner 1988-1022
Outer (LM 11949, LM 11910) Seal 1090