Technical FAQ
This is a compilation of technical questions asked by our customers.
Parts needed to install drivetrain
Following is a list of parts and part numbers for items commonly used to finish our cars. 427 parts are for engines in the FE family (390, 427 and 428). 289 parts are for engines in the Windsor family (289, 302 and 351W). We have tried to provide manufacturers names and part numbers. Most of the parts are available through large parts houses like Summit and Jegs. They should also be available through your local auto parts store or performance dealer.
| Clutch Parts: | ||
|---|---|---|
| Application | Description | Mfg & Part Number |
| 427 w/Tremec | 12 inch racing clutch | Mcleod 260873 |
| 427 w/Tremec | 12 inch street clutch | Mcleod 260173 |
| 427 w/Top Loader | 12 inch clutch | Mcleod 260863 |
| 289 w/Tremec | street use 10.5 X1-1/8 X 26 reverse hub | Mcleod 260170 |
| 289 w/Tremec | performance use 11 X 1-1/8 X 26 REVERSE HUB Kevlar:p/n updated 04MAR10 | Mcleod 260571 |
| 289 w/Top Loader | small input shaft, 1 1/16 10 spline | Mcleod 260831 |
| Pressure Plate: | ||
| 427 w/Tremec | 12 inch | Mcleod 360821 |
| 427 w/Top Loader | 12 inch | Mcleod 360821M |
| 289 w/Tremec | 10.5 inch | Mcleod 360048 |
| 289 w/Top Loader | 11 inch | Mcleod 360850 |
| Scatter shield/bell housing: | ||
| 427 Tremec or Top Loader | scatter shield/bell housing | Lakewood 15210 |
| 427 Tremec or Top Loader | scatter shield/bell housing | Quick Time 6057* |
| 289 Tremec or Top Loader | scatter shield/bell housing | Lakewood 15200 |
| * If you are going to use a Quick Time bellhousing with an FE engine, you must use part 6057 whether you use the top loader or the Tremec. Do not order the Tremec bellhousing. Call if you have questions. | ||
| Flywheel: | ||
| 427 | aluminum flywheel | Mcleod 563210 |
| Check with your engine builder for help with flywheel selection. We recommend aluminum fly wheels to keep rotating mass down. | ||
| Other Clutch/Transmission parts: | ||
| 427 | external clutch slave cylinder assembly | Kirkham 00536 |
| 427 | pilot bearing | SKF B50HD |
| 427 & 289 | pressure plate bolts | ARP 150-2201 |
| 427 & 289 | flywheel bolts | ARP 200-2802 |
| Starters: | ||
| 427 | original block | Powermaster 3131 |
| 427 | Shelby aluminum blocks | Mcleod 810160 |
| Alternators: | ||
| 427 or 289 | alternator 3 wire type | Power Master 7078 |
| Ignition: | ||
| 427 & 289 | ignition coil | MSD 8202 |
| 427 & 289 | ignition coil bracket | MSD 8213 |
| 427 & 289 | 6AL ignition box w/rev limiter | MSD 6420 |
| 427 & 289 | 6AL-2 ignition box w/rev limiter | MSD 6421 |
| 427 & 289 | 6 Digital+ ignition box | MSD 6520 |
| 427 | pro billet distributer | MSD 8594 |
| 289,302 | pro billet distributer | MSD 8582 |
| 351W | pro billet distributer | MSD 8584 |
| You will need either the 6AL or the 6 Digital+ from the list above. | ||
| Oil Pans: | ||
| 427 | 427 cobra style pan | Armondo 408 |
| 289 | 289 cobra style pan | Armondo 406 |
| Armando's Racing oil pans, 15476 Montana Ave. El Paso TX. 79938 (915) 849-7622 | ||
| Misc. Parts: | ||
| 427 | header bolts | ARP 100-1102 |
| 427 or 289 | voltage regulator (fits an original Cobra | Niehoff FF169-B |
| 289 | bell crank kit for Weber carbs | Mr. Gasket 1523 |
| 289 | header gaskets | Fel-Pro 1415 |
| 427 or 289 | fuel pressure regulator, bypassing | Mallory 4309 |
| 427 | dipstick (made for Chevy big block) | Spectre 5720 |
| 427 | air filter | K & N E-2570 |
| 427 | air filter | K & N E-1025 |
| 427 | air filter | K & N E-2630 |
| 427 | oil filter | K&N-HP-3001 |
| 427 | oil filter | Fram PH8A |
| 427 | remote oil filter mount gasket (used on older Kirkham style) | Fel-Pro 70135 |
| 427 | water pump gasket | Fel-Pro 427 11760 |
| 427 & 289 | Top Loader rear transmission seal | National 9613-S |
Carbureted engine starting
Modern fuel injected engines generally start immediately and automatically adjust to ambient temperature and altitude conditions. They also keep themselves at the correct operating temperature. In keeping with the spirit of the originals our cars are usually carbureted and many other systems onboard are manually operated. Because of this we need a simple starting and operating procedure
With a carburetor, especially in cold weather, the fuel doesn't mix with the air as well, and the engine needs a bit richer of a mixture to start. In older cars the choke restricted air, richening the fuel/air mix. Our thoroughbreds usually lack a choke; so instead of blocking off the air, we need to add a little fuel. That is the theory now lets put it into action.
FIRST, we need to do a little pre-flight check. Turn on the fuel pump and listen to see if it is working. Turn on the cooling fans and listen to see if they are working. Turn the fan back off. (Remember to turn it back ON again once the engine heats up to about 80-85 degrees Celsius.) Leave the fuel pump on and check the fuel pressure gage for pressure. The fuel pressure should be about 5-7 psi.
The fuel bowls should already be full from the last time the engine was run so you just need to pump the gas pedal about ½ way down 2-3 times quickly and then DON'T touch the gas pedal any more. If you touch the pedal again you risk flooding the engine.
Crank the engine until it just starts to fire then push the gas pedal down about 1/4 of the way and HOLD it there until it starts. If the engine doesn't fire, then repeat the procedure. If it doesn't start after a couple of tries then there is probably something else wrong. If it is extremely cold outside, or if you haven't driven your car in a while, you may need to pump the pedal 4-5 times instead of 2-3 on the initial priming of the engine. As you get to know your car better, you can fine tune this procedure.
Fluids
Differential
Warning: The differential covers that we use locate the drain plug approximately an inch higher than the original covers. (Original style covers are no longer available.) Do not fill the differential to the drain plug or it will cause heat and high pressure in the diff and blow out the seals.
3.25 pints 80W-90 NON-synthetic* gear oil + 4 oz of friction modifier additive.
85W90:
GL-6 (GL-5 is acceptable, but not preferred). Valvoline & Mobile seem to work well.
4 oz. Friction modifier.
Use Auburn Friction Additive (Auburn part number 504102) in differentials with Auburn gearsets and Ford Friction Modifier (Ford part number M-195-46-A12) in differentials with Dana gearsets. Use the old petroleum based Ford Modifier instead of the newer synthetic.
*Synthetic are TOO slippery, causing the diff's internal clutches and cones to slip, chatter, and wear out.
Transmission
Tremec TKO 600
Approximately 5.28 pints Dexron III ATF fluid. (Dexron 3) The transmission should be filled through the fill plug located on the passenger side of the transmission. Fill to the bottom to the plug hole.
Top Loader
Approximately 2 quarts of 75W-90 gear oil. You can use 80W-140 gear oil in hot climates or in heavy duty applications.
Clutch
DOT 3 brake fluid. We recommend Ford PM-1 DOT 3 fluid.
Brakes
DOT 3 brake fluid. We recommend Ford PM-1 DOT 3 fluid.
Replacement Parts and Part Numbers
| Part Description | Part Number/Spec |
|
| Headlight bulb | GE H6024 or equivalent | |
| Parking light, turn signal, tail light, and brake light bulbs | Sylvania 1157LL or equivalent | |
| Fuel Pump | Holly Red, 12-801-1 | |
| Brake Pads, Front | Wilwood PolyMatrix 15Q-6829K | |
| Brake Pads, Rear | Wilwood PolyMatrix 15Q-6824K | |
| Brake Fluid | Ford PM-1 DOT 3 | |
| Clutch Fluid | Ford PM-1 DOT 3 | |
| Differential Gear Oil | 80W-90 NON-synthetic GL-6 (or GL-5) w/ Ford part number M-195-46-A12 | 3.25 pints |
| TKO Transmission Fluid | Dexron III ATF fluid, aprox | ~5.28 pints |
| Top Loader Transmission Fluid | 75W-90 Gear Oil | ~2 quarts |
Bare aluminum finish care
Leaving your car in bare aluminum is a great way to show off your roadster and let others know that it isn't a dune buggy. Most of these cars don't spend a lot of time in rain, snow, or other harsh climates so the finish doesn't see a lot of abuse but there are times when your finish may need some touch up.
For our sanded or brushed finish we recommend water in a spray bottle and paper towels to remove dust and road grime. If the grime is really nasty you can use Windex brand window cleaner. (Some brands of cleaner will actually stain the aluminum so be sure to test your cleaner in an inconspicuous area of the car.) If your car does get rained on, wipe it off if possible so that the rain will not spot the car. Customers in smoggy areas should clean the water off quickly so that it doesn't etch into the car.
If you do get a stain or scratch in the finish, you can use sandpaper and Scotch-Brite pads to "redo" the finish. Use red Scotch-Brite pads and a high quality 120 grit bodywork sandpaper. You can get the sandpaper in sizes precut for a body file board (long and skinny). If you cut these in half they will be about the length of the Scotch-Brite pad.
If the stain or scratch isn't too deep you can use the Scotch-Brite pad to clean up the finish. Brush the finish in long straight strokes going with the "grain" of the finish. Be careful at the end of each stroke so that you do not move across the grain. If you do, it will leave visible scratches. When you first start with the pad it will be "sharp" and cut well, after you use it for a while it will lose its abrasive properties. After the pad wears in it will take a little more effort, but you can still use the pad and for most cars the finish produced with a dull pad will more closely match the finish already on the car.
For deeper scratches or blemishes you can use the sandpaper followed by the Scotch-Brite. Start with one of the half sheets of 120 grit paper. Fold a Scotch-Brite pad in half length wise and use it as a backing for the sandpaper. Again, use long straight strokes and go with the grain already on the car. Be careful not to move the sandpaper across the grain or you will be able to see the scratches. The sandpaper will cut pretty aggressively so be cautious. You shouldn't have to use a lot of pressure and you should not spend too much time in one spot. Use long strokes so you don't "flat spot" the place you are trying to fix. Once you have cleaned up the problem area with the sandpaper, use the Scotch-Brite to match the finish to the rest of the car. It is good to tape off any chrome parts (hood handles, headlights, turn lights, etc...) so they do not get scratched. If you are working next to a polished area, tape it off so that you will not accidentally cross over and scratch the polished finish.
For polished areas on the car you can use water or Windex and microfiber towels. If you get a scratch or blemish in a polished area use Mothers aluminum and mag polish and microfiber towels to clean and re-polish. Carefully clean the area with water and then dry with a clean towel. Apply a dab of Mothers to the towel and work it into the area that needs to be polished. Wipe off any excess polish with a clean towel. If you are working next to a brushed finish, tape off the area so that you will not cross over and gum up the brushed finish.
Alignment specs
| Alignment specs | Street |
| Ride Height, Front | 4.5" |
| Ride Height, Rear | 5.25" |
| Caster Front | 3-4° positive |
| Camber, Front | -½° |
| Camber, Rear | -½° |
| Toe, Front | 3/32" toe in w/radial tires |
| Toe, Rear | 3/32" toe in w/radial tires |
| Tire Pressure | 30 psi. |
Ride height is measured on a level surface from the bottom or the frame rails to the ground approximately 1/2 inch inboard of the end caps.
For track: start with above as baseline.
Choosing a transmission and differential gear ratio
Transmission
We use and recommend two different transmissions in our cars. The Ford Toploader and the Tremec TKO 600.
Toploader
The Ford Toploader transmissions are 4-speed, fully synchronized transmissions built between 1964 and 1973 in over 130 different configurations. The transmissions were built with different gear ratios, case sizes, and output shafts. The Toploader gets its name from its revolutionary (for the time) case design the put the access plate on the top of the case instead of on the side. This made the case stronger than previous designs that had the access plate on the side of the case. By the mid 1990s these transmissions were becoming fairly scarce but now there are several companies making reproduction of these gear boxes with either cast iron or aluminum cases and upgraded internal parts. Original Cobras came with a 14" tail housing, 1 3/8” input shaft, 28 spline output shaft, and "close" gear ratios.
For more information on Toploaders visit: David Kee Toploader Transmissions
Tremec TKO 600
The TKO 600 is a modern 5 speed overdrive transmission rated at 600 lb/ft of torque. It is available with different overdrive gear ratios, .82 and .64. We recommend the .82 ratio. The use of these transmissions require that a mount be welded to the frame.
Rear end gear ratios
Because of the wide variety of engines and the RPM range/powerbands in those engines, it is very difficult to give a one-size-fits-all recommendation for a gear ratio. The following ratios are good recommendations for most setups. Feel free to call us with any questions about your specific application.
| Engine Type | Transmission Type | Gear Ratio |
| Small Block | TKO | 3.54-3.73 |
| Small Block | Top Loader | 3.54 |
| Big Block | TKO or Top Loader | 3.31 or 3.42 |
Installing Knock-Offs/Spinners/Wingnuts
Since our cars use only one “lug nut” instead of five, you might think this is a simpler method of holding the wheel and tire on the car. While it is simpler in that there is only one part instead of five, there is only one point of failure so we need to use some extra caution when removing and installing knock-offs.
Tools needed:
Knock-off hammer or mallet
Traditionally these have been made of lead. We use a large (5 lb.) nylon mallet in the shop. Lead works well but does not last as long as nylon. We get our mallets at the local home builder supply place.
Safety wire and pliers
Safety wire is a must when properly installing knock-offs. Use 0.032 wire. A set of safety wire pliers will make the job of installing the safety wire easier. You can buy safety wire and pliers in kits from racing and aircraft supply stores (Aircraft Spruce and Specialty).
Anti-seize
This can be purchased at most automotive parts stores. If you don't use anti-seize, you will experience the following:
Best case: You will ruin the rim and the knock off with galling. It is highly unlikely you will stop at best case.
Worst, and most probable case: You will seize the nut onto the hub and you will experience all sorts of new words in your vocabulary as you CUT THE WHEEL, WING NUT, AND HUB apart to disassemble the whole mess. You will be left with mess on the floor and a big hole in your wallet to fix the mess. You MUST anti-seize the threads AND the face of the knock off where it contacts the wheel face. We even anti-seize the drive pins a little.
Jack
We use a low profile racing type hydraulic jack when we are away from the shop and don't have a lift available.
To remove knock-offs and wheels start with the car on the ground. We leave the car on the ground so that the force from removing the knock offs isn't transfered directly to the bearings. Remove the safety wire from the knock-off. Loosen the knock-offs by hitting them firmly with the hammer. Remember, the knock-offs on the left side (left as if you are sitting in the seats) of the car have right-hand threads; the knock-offs on the right-side of the car have left-hand threads. If you can get a good angle it helps to strike the knock-off on different wings. Once the knock-offs loosens you can then raise the car so that you can remove the wheel and tire.
Installing the wheel, tire and knock-off is basically a reverse of the removal, but it also requires some finesse. Start by applying a thin layer of anti-seize to the drive pins and threads on the hub. Place the wheel and tire on the hub by lining the wheel up with the drive pins and sliding it in place. Apply a thin coating of anti-seize to the threads on the knock-off and the area where the knock-off seats on the wheel. Start the knock-off onto the threads. Remember left-hand threads on the right, right-hand threads on the left. Tighten the knock-off until it starts to touch the wheel. Grab opposite edges of the tire and wiggle it side to side and up and down to ensure that it is seated on the hub and that the drive pins are engaged properly. Tighten the knock-off. Repeat until the knock-off is as tight as you can get by hand. You can give the knock-off a wack with the hammer to ensure that it is seated. Now you can lower the car to the ground and finish tightening the knock-off. To tighten the knock-off, strike the wing with the hammer. You should be able to feel the knock-off turn each time you strike it. When it is seated tightly the hammer will bounce back differently because the knock-off has stopped turning. It takes a little practice but eventually you will get a feel for this. Give it a few more wacks to ensure that it isn't moving anymore. You should not have to use “gorilla” force to tighten the knock-off. The drive pins transfer the force from acceleration and braking to the wheel, the knock-off holds the wheel against the hub.
Now it is time for the safety wire. There should be a hole in one wing of the knock-off. Run the safety wire from this hole to a spoke on your wheel. The wire should be installed in a direction so that it is holding the knock-off tight. This wire does not hold the knock-off in place but it is used to show that the knock-off has not come loose. Please bend ALL safety wire ends over to show you care and to prevent safety wire sized holes in your hands. Besides showing that you care, it looks cool. Never drive a car without the safety wire in place on all wheels. Checking the safety wire on each wheel should always be on your pre-flight checklist. Remove your wheels to clean your hubs and knock-offs and re-apply anti-seize once a year to prevent corrosion (more often if you live in a damp or salty ocean climate or if you use your car to trailer a boat).
Use these answers at your own risk. Please bear in mind that there are is no connection between Kirkham Motorsports and any other entity linked to or mentioned on any of our webpages. There are no authorized Kirkham Motorsports dealerships, and we cannot certify any business we mention, nor do we warrant anyone's work. All links and information are provided purely to help you identify businesses that offer services and products you may find helpful. Carefully research any entity with whom you choose to do business with before starting anything.
