Chuck's Jaguar D Type Build


Front Brakes: the Solution

Here is our plan.

Wilwood manufacturers a six piston caliper that is narrower and has the mounting ears in the same location as the calipers provided by RCR. They are, unfortunately, double the cost of the calipers supplied by RCR. They are described as “slim” and provide about 3/8” more outside clearance. When set side by side the difference in width between the two is apparent.


The part numbers are:

Item 120-13383-BK, Left hand
Item 120-13382-BK, Right hand

The spacer plate issue may be solved by simply moving it from the inside to the outside surface of the rotor. By putting it on the outside of the rotor, the rotor is moved inward 3/16”. With the spacer plate reversed and the narrower calipers the setup measurements are within spitting distance of the needed clearance.

The really good news is that the offset dimension on the replacement rotors is .23 inches less than the calipers provided by RCR, which is close enough to the thickness of the spacer plate that the RCR caliper support can hopefully be used without the need to machine a new one. Note however that the RCR bracket must be the “02” or second version.


But there is a bit more to putting this all together. Now we need to move on to the reaming and grinding to make sure this will work.


Front Brakes: Assembly

Modifications were needed for the parts to fit with this revised orientation.

First, the five holes in the brake rotors need to be reamed out to 37/64” to clear the shoulders on the stud bolts.


Second, the spacer plates need to have the inner ring beveled to fit snugly up against the hub in its new outside position. This was accomplished with an angle grinder using a rasp bit, followed by sanding with 180 grit paper. The goal is to make a bevel on the lip side that matches the machined bevel on the flat side. This is needed so the lip on the spacer will seat properly on the hub.


Third, the spacer plate bolt holes need to be reamed to 9/16” to fit over the half inch lug bolts.

A single 1/8” spacer was all that was needed to assure adequate clearance which is a huge improvement from the more than 5/8” needed with the calipers supplied by RCR.


These calipers look awesome once installed. Too bad they won’t be seen when the wheels are in place. These are impressive units that will give the D Type more stopping power than it will likely ever need.


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Slight topic change since I’m on the downhill slope of my engine rebuild. What alternator were you planning on using? I’ve recently learned about ‘mini alternators’ that apparently are used in hot rods and more modern cars. I’m not going for a completely authentic look with my engine, so I’m definitely looking into it as an option. Any knowledge of what minimum amperage is needed for the D Type?


Slight topic change since I’m on the downhill slope of my engine rebuild. What alternator were you planning on using? I’ve recently learned about ‘mini alternators’ that apparently are used in hot rods and more modern cars. I’m not going for a completely authentic look with my engine, so I’m definitely looking into it as an option. Any knowledge of what minimum amperage is needed for the D Type?
I have a vintage looking generator style single wire alternator, but I am not sure I will use it. I plan to tackle that project once the engine is set in the chassis. The amount of space available may have an impact on what will be used.

You won't need much amperage since there will be few things that will use significant power. The headlights will probably be the most significant power drain.


Front Brakes, Final Details

Wilwood sells a number of brakes pads depending upon the application. We used the BP-10 pads on the GT40 and they worked very well, so the same pads were selected for the Jaguar. Part #150-8855K.


The satisfaction of easily sliding the pads into place perfectly centered was the final endorsement confirming this design.


With this issue sorted, the brake parts will be removed so that the front suspension issues can be more easily sorted. That will be the subject of posts for another day.

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Fuel System Part IV

Although vapor lock should not be a problem, Thermo Tec sleeves were added to the sections of the fuel line closest to the engine. Thermo Tec heat barrier was added the tunnel adjacent to the engine on both sides. I used this product on the GT40 and found it quite effective. A pattern was made and the edges cut about a quarter inch from the edges to assure it would be placed on a perfectly flat surface. The aluminum was wiped down with acetone before the material was applied.



The fittings were added to the Aeromotive fuel pressure regulator, including the Aeromotive pressure gauge. (Aeromotive had a deal when I ordered it direct: buy the regulator and the gauge was free). Fuel pressure gauges are typically not very reliable, but this looks like a good quality unit. Frankly once the pressure is set the gauge can be removed.


The roll over valve was added to the fuel tank. Summit Racing, part #TNK-VV. The roll over valve needs to be installed first, then the pick-up tube, and finally the ninety degree fitting. Loctite 567 was used on each.


The plumbing for the fuel system is now complete.

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Chuck, if you have the fuel tank that comes with the D-Type kit, I would like to see a picture of them side by side for a size and shape comparison. Also, are you modifying or deleting the interior of the spare tyre boot to accommodate the different tank?



Pics, per your request. Dimensions and details of both tanks posted January 3, 2020.



The revised fuel tank will have no effect on the design of the boot compartment.


Rear Suspension - Initial Alignment

More than a year ago the details for building the revised “A” frames and replacement trailing arms were posted. We then discovered an issue with the differential requiring it be rebuilt, documented May 2019. Last November the secondary rear frame / fuel tank support was designed and built. The fuel tank frame was added in January. These parts have now been installed and we are ready to finalize assembly of the rear suspension. It has been a busy year.

We started by jacking up the rear axle to ride height and placing floor stands under the axle so that the center of the hub is approximately 14 ½” above the garage floor. The trailing arms should be approximately level.


We compared the distance from the bottom of the shock absorber brackets to the floor, left and right. They should be equal and visually line up, left to right. If they don’t, any significant misalignment between the brackets needs to be corrected or the suspension will bind before it reaches its full range of travel, as will be revealed in the next step.

Next, loosen the lock nuts on all the trailing arms. You should be able to turn each of the trailing arms a quarter turn easily. All four must be ‘slack,’ that is free of tension. With all four so adjusted compare the lengths measured from the center point of the mounting bolts. We want the two tops to be approximately the same length and the two bottoms to be approximately the same length. If they are within a 3/8” we can continue. If not, one of the brackets welded to the axle may not be lined up correctly with the other which could lead to binding when the suspension is moved through its range of travel.


All four trailing arms can now be adjusted, typically a half turn at a time. The goal is to make them approximately equal and also to make sure the axle is perpendicular to the center line of the car. Mark a reference point, right and left, on the axle and the rear wall and make the measurements. This needs to be fairly exact since we want the car to track straight. When done the trailing arms will be around 11” to 11 ½” long, measured from the center of the bolts. Remember the arms must turn freely and not bind – so some variation in length is not a problem.


The shock absorbers were set in place. Once everything was properly in place we set the springs so that 3 ¾ inch of threads were exposed at the bottom. Obviously this will need to be revised later.

We applied a coat of silver color anti-seize to the threads before attempting to adjust the shocks. I like to spread it with a small paint brush just in the areas where it will be needed.


Once the alignment is satisfactory, the Nyloc nuts for the trailing arms can be tightened. We did not use a torque wrench since these connections are in shear rather than tension and the goal was to tighten the six connections enough to take the slack out. We did, however, put a dab of white Torque Seal on these connections. If ever a nut would begin to loosen this will give a quick visual reference. Final adjustments will likely be needed once the body is in place.


Rear suspension nearly complete, differential rebuilt, brake calipers replaced, rotors turned, fuel tank installed; it feels like we are finally making some progress.


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Randy V

Lifetime Supporter
Absolutely fabulous progress to this point Chuck!
Many years ago while working on a race team, I learned from my crew chief to discard the locking rings for the coil-over adjusters and just use a simple 2” stainless steel hose clamp, butted up against the adjusting ring. We never had one move on us, nor had any threads that galled. A side benefit was that we could easily gain extra clearance for loading into the trailer by jacking up each end and spin the adjusters down snug to the springs. At our destination, after the car was unloaded, it was easy to jack the car back up and spin the adjusters to be snug to the clamp - thereby maintaining proper ride height and loading on each corner...

Randy V

Lifetime Supporter

Neat idea! Have you done that on your GT??
I have not done it on the GT as it has been sold now. I have done it on every other racecar that I’ve owned or crew-chiefed for roughly the last 30 years though... I can safely call it a tried-and-proven method...
You can see they have the torsinebar mounted like in e-type, but it goes the hole way thou the chassie, See the new mountings they hav made for the T-5 that is in this car. I think Jaguar mounted the engine in four rubbermounts in the forward frame chassi, and one leaver at the gearbox.


Rear Suspension Alignment – Travel

When all the bits and pieces were in place and tightened down we did a final check of the rear suspension travel. The rear end was raised until it was stopped by the shocks bottoming out. This was measured at four inches of upward travel. At that point there was one inch of clearance between the bottom of the fuel tank and the top of the differential.



Next one side of the axle was lowered while the other was still raised, checking for binding. There was none.


Bump stops, QA1, part # BC02, were added at the top of each shock to cushion the limit of travel, which I suspect will never be reached under typical driving conditions. Note these are installed with the tapered side down. The washers that came with them were not used.


The rear suspension will have approximately eight inches of total travel, four up and four down. The two wheels can pivot independently angling the axle without difficulty. There is no concern about the differential hitting the fuel tank. The ability to achieve this range of travel and maintain the clearance to the fuel tank is the result of the design revisions to the rear suspension; more specifically the addition of the second A frame, and the redesigned fuel tank, detailed in previous posts.
Chuck, do you know what the hole in the cockpit between the two seats is for? I have seen it in both the original D Types and the RCR reproduction. I'm assuming it wasn't for disposing of candy bar wrappers during long races.