So... I guess I am a bit/ton younger then most of the people I have met that own (not just drive) formula cars. So I use social media as a way to gain knowledge and leave knowledge, and also for my own recollection. I see that there is no section for build sections on this forum for older FC cars so.
Made room in my garage for a new project by selling my only car that I ever bought new. That was also the same car I spent the last 14 years modding to a car that finally won the season championship and setting a new track record. And not much more to the car to do. Well except cutting the roof off. It was a wagon. I figured it might be better to buy won that it was already done.
If it matters to look at a door slammer here is my old build thread https://www.mazdas247.com/forum/show...N-A-ST2-thread But as I said before here is where I will leave a digital track of experiences, opinions, photos, and videos. I only hope this helps people as well as to myself, and not to forget to promote the people whom already have helped me!
Some intro pics to come later. I am sick as hell.
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just the good stuff
diff preload and backlash
"The side cover preload must be set with NEW bearings and the set up for it done with NEW set up races. Saving the old ones for set up won't work. Total shimming must be done BEFORE you put the pinion back in. This is the only way you can really measure or even feel the amount of preload in there as the pinon turning will get you all messed up.
The total shim needed will be the amount to hold the diff in place plus some preload- about .008 will do you fine. BUT, the total is shifted from side to side AFTER you put the pinion back in. THIS shifting is what determines the back lash.
The pinion depth must also be set if it's new. This can only be done real well with the proper tool for it. And of course when done you'll need to check the top gear float against the carrier to be sure you didn't shift the pinion back too far (if it's new or you for some reason added shims) and the top gear is sandwhiched to the carrier. Seen those deep thrust washer pockets? That's why.
Now that you've got the total shim established, the pinion depth establishe, assemble it with the dummy races and see where the lash takes you. Keep it at about .005-.007 and you'll be ok. That's assuming it's used and that you check it in various spots. What no dial inditcator? (or set up shims, or depth tool...) then look for a tic-tic for lash rather than a klunk-klunk. Better too lose than too tight. Too lose though and you'll be tearing up the clutch in time....
Ok, when you need to get it there, simply swap the shims from side to side to achieve this result. When done put in the new races (you did change the diff bearings right?) and verify that your dummy races are not dummies. Change if needed of course. All of this requires the heating and cooling of the side covers and the measurments taken AFTER it cools. Screw up now and you'll be taking it apart again and waiting for it to cool all over again!
If the preload is right, the lash right, and the top gear float right you're in business. Turning the box by hand (both studs forward) will produce a light drag on it. Don't panic if it's a bit tight, it'll come into its own."
Torque numbers for gear box
https://taylor-race.com/sites/defaul...MK9numbers.pdf
Reusing Locking Nuts
"The FAA has issued guidelines on the reuse of locking nuts. Specific recommendations have been published for larger sizes (7/16-20 and up), but the general rule is that you should not be able to turn the nut by hand once the locking portion engages the male threads. If you can turn the nut with your fingers, it must be replaced. When in doubt, replace!"
Carb Leaks
FLOODING (OVERFLOWING) Fuel overflowing from the carburetor may be caused by a number of issues:
(1) Float/fuel valve incorrectly adjusted
(2) Defective fuel valve
(3) Defective float
(4) Excessive fuel pressure
(A) incorrect or defective fuel pump
(B) clogged or missing tank vent
(5) Cracked housing
Discussing in order:
(1) Make certain that you have the float adjusted to the manufacturer’s original specifications, and make sure you know HOW the manufacturer measured the adjustment. Some manufacturers specify the distance from the float to the casting without the gasket, some with the gasket, some the distance to the fuel level in the bowl at a specified pressure, and Rochester was probably the most creative, often measuring to a “dimple” on the float itself or the float seam. If you buy an aftermarket rebuilding kit, NEVER rely on the generic specification sheets which come in the kits. Check your factory shop manual or the carburetor manufacturer’s manual.
(2) If the fuel valve is defective, replace it.
(3) If the float is brass, check this link: Brassfloats , if a material other than brass, and there is any doubt, replace the float.
(4) A fuel pressure gauge placed right at the carburetor will confirm/deny the presence of too much pressure. However, one should consider the clogged or missing vent. The fuel tank MUST be vented, or no fuel can exit the tank. Many older vehicles were vented through the gasoline cap. Vented caps were obsoleted because of smog emissions regulations. If the tank vent is clogged or missing, normal ambient temperature change will create either a positive pressure or negative pressure (vacuum) on the tank. Some tanks are located close to the exhaust. As the engine warms the hot exhaust heats the fuel in the tank, and can create excessive pressure in the tank.
(5) Cracked carburetor housings are quite rare; in more than 50 years, I have only seen a hand-full, but the issue CAN exist, ESPECIALLY if the “mechanic” feels the necessity of using some form of Teflon (either tape or paste) on a tapered fuel fitting. Teflon is a fabulous lubricant, and will allow anyone to apply excessive torque to the fitting threads and crack the casting.
FUEL LEAK BY THROTTLE SHAFT(S) A common complaint today is fuel dripping out of the throttle body by the throttle shaft AFTER the engine is switched off. While a number of issues may cause this problem, by far the most common issue is the volatility of modern fuel. Mechanical fuel pumps have a check valve which prevents fuel from moving back to the fuel tank. The problem is as follows:
(1) After the engine is switched off, heat from the engine heats the fuel in the fuel line.
(2) The expanding fuel (increased volatility) creates pressure in the fuel line from the pump to the carburetor.
(3) The check valve prevents the fuel backing up through the fuel pump.
(4) The pressure increases to a point the float/fuel valve combination in the carburetor cannot withstand the pressure.
(5) An amount of fuel (usually from a teaspoon to a couple of tablespoons) flows into the fuel bowl of the carburetor.
(6) This raises the fuel level in the bowl above the main discharge nozzle(s).
(7) Fuel flows through the main discharge nozzle(s) and drips onto the throttle plate(s) which is/are closed, and exits out beside the throttle shaft(s) dripping onto the intake.
Possible solutions:
(1) IF POSSIBLE, AVOID ETHANOL LACED FUEL! Sometimes you can buy real gasoline at a marina
(2) Buy the lowest octane name-brand fuel that does not ping or detonate in your engine (the higher grades often have more ethanol)
(3) Install a “vapor return line” (take a look at return lines used on many factory air-conditioned cars)
(4) Learn to live with the issue.
Carb jetting
Carb Jets:
The secondaries should be mechanically operated. This means that any time you are at full throttle (and this will be 95% of the time), both the primary and secondary will be open. If you are seeing a discontinuity in the EGT's, that may be due to the auxiliary enrichment tubes (put in by various engine builders to modify the fuel distribution) starting their flow with a slight delay - this is normal.
The main jets are located in the bottom of the float bowl. To change them you remove the top of the carb (6 screws) -- if you are careful not to tear the gasket, it can be reused. You will probably have different jets for the primary & secondary venturi -- so be careful to note what size is currently used for each one. A "one jet leaner" usually mean a differnence of 5 (i.e. change a 175 to a 170 - smaller numbers are leaner).
Your carb also has air corrector jets (aka A/C) -- you also remove the carb top to access these -- but they are located on the upward face of the carb body. Again, primary and secondary values may be different. The air correctors adjust the mixture just at the high flows (i.e. high RPMs) -- three steps of A/C jets is about the same as one step of main jets. A larger A/C jet will make the mixture leaner, and a smaller one will make it richer.
Finally, you will find idle jets on the side of the carbs in the main body, just below the top. You unscrew the holder, and the jet sits in that. Watch out not to lose the rubber o-ring under the jet holder. Idle jets are hardly ever changed, but you should pull them out to make sure a piece of debris hasn't clogged the very small orifice.
The mixture screw located near the base of the carb will adjust the mixture at idle. With the engine running at idle (usually 900 - 1000 RPMs), screw it in until the engine starts to run rough, then back it out again until the engine again begins to sound a bit rough -- at that point, screw it back in 1/4 to 1/2 turn and you're all set -- a smooth running engine.
DaveW’s jets at one time when he had a Pinto were:
JET PRI SEC
AIR 200 140
FUEL 135 165
(FOR AVGAS, ~55F)
Rollin Butler’s starting point.:
JET PRI SEC
Air 175 160
Fuel 145 155
Primary air is always bigger.
Secondary fuel is always bigger.
From: Dave Weitzenhof
1. The primary jets have more effect on cyl 2 & 3 than on cyl 1 & 4. The secondaries have more effect on 1 & 4 than on 2 & 3. Therefore, if 2 & 3 are rich compared to 1 & 4 (plug check after clean-cut, etc.), lean primaries or richen secondaries, and vice-versa.
2. A long time ago, before the widespread use of EGT sensors, I very successfully used a seat-of-the-pants trackside method of setting the over-all degree of richness. I would warm up the engine to operating temp, and then immediately run it to ~3000 rpm, let the rpm stabilize, and then open the throttle wide open for ~1 second. If the engine died or hesitated for more than ~1/2 second, the jets were too lean and needed to be richened. If the engine just barely hesitated and then revved cleanly, the jets were just right. If it picked up smoothly with no hesitation, the jets were too rich. All of this assumes no major carb or other engine problems. This really did work quite well.
Tire pressures
Ah... tire pressures.
It is an art form.
I looked over a few years of notes when running a Reynard with Hoosier bias tires.
Cold pressures were all over the map.
The goal was to not be over 19 to 20 hot.
When the car was sorted and the weather was normal we would start with 15 all around.
Cold days with long straights, maybe higher.
Used tires usually take a bit more air. The thinner the rubber pad, the less it holds in heat.
Softer pressures can cause the carcass to flex more and thus build heat. Too soft and the footprint will distort.
Tire pressures also effect spring rate.
If i was coaching you at your first sessions, I'd start you at 15 square. After you do some hard laps I'd call you in and check pressures on pit lane. Then adjust accordingly and send you out again.
We'd set ride height so it would just "nick" a few places on the track. That would mean that on the out lap on cold tires the rub strips would be talking you you a lot of places until the tires warmed up.
Remember, if it was easy, everybody would be doing it.
Setting the timming
I'm hoping I timed this right. I believe the cam is a touch behind/retarded cause that is what you guys run...
Gear Chart
Wheel Sealing Thread
http://www.apexspeed.com/forums/show...t=sealing+rims
Engine Stuff
Redline…..…...6800 rpm
Bore = 3.575"
Stroke = 3.029"
Rod length = 4.990"
Wrist pin = .944"
1 inch = 2.54 cm.
Race Engine Clearances: (BAT catalog)
Main Bearings……………… .002"
Con rod bearings…………… .0015 - .002"
Con rod side clearance……. .015"
Camshaft bearings………… .0018 - .0026"
Piston to cyl. Wall………… .005"
Top Ring End Gap………… .015"
Crankshaft end float………. .0032 - .011"
Camshaft end float………… .0016 - .0047"
Wrist pin………………….. .0007 - .00153"
Intake valve stem………… .002"
Exhaust valve stem………. .0025"
Intake valve lash………….. .010" cold ? (.008)
Exhaust valve lash……….. .012" cold ? (.010)
Race Engine Torque Specs: (BAT catalog)
Head bolt…………………… 85 lbs./ft.
Main cap bolt………………. 75 lbs./ft.
Rod cap bolt…(Stock)….. 35 lbs./ft ? (45) Oliver is different
Flywheel bolt ……………… 50 lbs./ft. ? (75)
Pressure plate bolt…………. 15 lbs./ft.
Oil Sump bolt……………… 8 lbs./ft.
Rocker Cover bolt…………. 5 lbs./ft.
Front Cover Bolt…………… 13 lbs./ft.
Water Neck bolt…………… 15 lbs./ft.
Camshaft Sprocket Bolt…… 35 lbs./ft.
Crankshaft Pulley bolt…….. 28 lbs./ft.
Intake Manifold bolt………. 15 lbs./ft.
Exhaust manifold bolt ……. 15 lbs./ft.
Carb to manifold nut……… 15 lbs./ft.
Spark Plug………………… 20 lbs./ft.
Phone Numbers:
Cricket Farm Motors 864-277-1268 Rollin Butler (SC)
Quicksilver 301-698-9009 Sandy Shamlian (Maryland)
Elite 262-306-1977 Steve Knapp (Wisconsin)
Farley 816-431-3550 (Missouri)
Loyning 503-775-2999 (Oregon)
Ivey 503-255-1123 (Oregon)
BAT 941-355-0005 (Sarasota FL)
Block:
GCR says:
2.0 NE series
Nominal bore 90.84 mm
Nominal stroke 76.95mm
Casting # HM6015BA or HM6015B3
Holes in the stock block to make sure you put something (a plug) into:
Water temp – right side rear
Front hole next to #1 journal
Inside oil filter
Dip stick
Top of block breather (filter side)
Rear of block below freeze plug
Two ports around jack shaft
Butler says main bearing clearance = .002 - .003"
Quicksilver says main bearing clearance = .002
New head gasket = .054", old = .052" Ford Motorsports "red"
Planing block will get you (per Kevin Roberts):
Plane .010" = 1.63cc/hole
Plane .020" = 3.26cc/hole
Head bolt torque………………………………85 lbs.
Pistons shall not protrude above the cylinder block surface @ TDC.
Main cap torque = 75 lb.
Pistons:
GCR says:
…shall be standard Ford production
Weighed with rings and pin, rod and bolts (no bearings)
p/n 80HM6102LA 1332.5 grams
p/n 85HM6102DA 1255 grams
p/n 21426 casting 21426 1255 grams
Piston p/n 21426, casting p/n 21426 (AE Hepolite)
oversize = std Grade "C" (90.83/90.82)
New Ford Forged Pistons p/n M-6102-B200 J&E
J&E Pistons p/n M-6102-B200
Wisco Pistons for 5.7 rods = #6119A3 .030" over
Butler says piston/wall clearance .0045" to .0055 max.
…..about pin high on the skirt.
Loyning says piston/wall clearance .005" max
Cast pistons are worthless.
Loyning says Moly top ring gap = .015"
Quicksilver says Moly top ring gap = .015"
Butler says Moly top ring gap = .015"
Old piston top ring = 5/64"
New piston top ring = 1/16"
Oil:
Sandy (QS) say use Valvoline 13/30 Synthetic if you have an oil cooler.
I use Mobil 1 15/50
Oil filter…………………Wix 51348? NAPA gold 1335, 1374 may be better
Cams:
Farley says cam timing 2 – 4 degrees retard.
Quicksilver says 3 degrees retard.
Max lift against cam angle with zero tappet clearance measured in mm:
Angle Opening Closing
0 10.442 10.442
45 3.86 3.86
90 0.20 0.01
Same for intake and exhaust.
Maximum valve lift against cam angle w/zero tappet clearance = 0.400 +/- .005"
New Crane cam is an allowable substitute.
Valve clearance: Intake .008" Exhaust .010"
Adjust between cam and follower…..
Cam timing: what the 2.0 "straight up" intake valve centerline cam timing number should be…
The long straight tracks should shoot for a 114 – 115 degree centerline (more retarded) on the number one intake lobe.
- To increase torque on the short tracks the number should be reduced to 112 – 113.
Note: Retarding the cam by installing a 3-degree offset keys will not guarantee the cam is retarded 3 degrees. There are many factors/tolerances that can change the cam angle so it needs to be checked and corrected with the appropriate offset key. I say should because the offset keys themselves are not always exactly what they are marked. Check – adjust – and re-check.
Rods:
Oliver Rods = M-6200-C200
Butler Rod bearing clearance = .002"
Quicksilver rod bearing clearance = .0015 - .002"
Butler says old cast rods only good for 2000 miles.
Rod p/n M-6200-C200 is permitted (Oliver)
Rod bearing keepers face oil filter on block!!!!
Butler does 45lb. Rod torque
Old forged stock rods:
70HM-6205-B-A
knot sticks out side of pin end "+8BA"
"F" on side of casting
Head:
Cylinder head volume = 49cc min. (not including head gasket)
Head gasket = .9mm min. thick
Cylinder aperture = 92 mm
Max diameter of inlet port at manifold head face 39.5 mm.
Max dimensions of exhaust port at manifold face 35.5mm X 27 mm.
It is permissible to reshape inlet and exhaust port by removal of metal within limits.
Inlet valve 42.2mm
Exhaust valve 36.2mm
Valve stem 8.4mm
Butler uses yellow stripe valve springs (BAT).
Valve clearance: Intake .008" Exhaust .010"
Adjust between cam and follower…..
OK. I called QS and asked what they do to set the valves cold.
When they set up the head on the bench, for the intakes, they use 0.010 on cylinders 1-3, and 0.009 on cyl # 4. For the exhausts they use 0.013 for # 1, and 0.012 for the rest. They might have to adjust one or two slightly hot after they're run in, but that gives them the desired 0.008 intake and 0.010 exhaust (hot).
So the 0.002 extra clearance, as I said before, seems about right for cold valve adjustments of a head mounted on a block.
Head bolt torque………………………………85 lbs.
Flywheel:
Min weight = 14.4 lb. w/ring
Butler says 85lb w/blue locktite.
ARP says No Washers under bolts! P/N 151-2801
Torque to 75lb. W/ARP moly lube.
Torque to 85lb w/ 30wt oil.
Tightening sequence:
1. 70 lb.
2. Rap with hammer
3. 70 lb.
4. 75 lb.
Titan Oil Pump:
The chamfer on each round pump gear goes down into the pump body spigot.
Crankshaft:
Min. weight = 27.5 lb.
Ignition systems:
Spark Plugs…………NGK AP8FS <AP9FS>? (NGK 2227?)
.028" w/points, bigger w/electronic ignition
Bosch – Pertronix #1843
Crane 3000-0021 (or 700-0021) and 700-2231
Points……… .013… dwell 48 – 50 degrees
Points really around .014 !!!!
Carb issues:
Is it dumping fuel at idle (too high float level) or…
During cornering (need to solder shut the secondary idle jet)? or…
Is it some other problem?
Dave W. says: Is the secondary idle jet still working (open)? If it is, solder it shut. Fuel will slosh in the carb and come out through this jet into the throttle plate area, causing a bog. This is exacerbated by higher float levels.
Barry Haynie said: An interesting twist to this phenomena I often experience is the motor shutting off under very hard straight line braking. This seems to be a float-level sensitive deal. By raising the level (icroscopically!) and testing and resetting etc I can get it to not do this.
Any comments on this or similar experiences?
Dave W. replied: Barry, since the float bowl is at the front of the carb, meaning that the jets are in the rear of the bowl, it sounds like you are uncovering the jets, causing a very lean mixture, stopping the engine. As you said, raising the float level would help this, but may cause fuel to slosh into unwanted places. QS does extensive baffling, etc. to prevent this.
From one of Keith's previous posts:
"I set the seam in the float, parallel with the carb top and have a 1/4" float drop. Remove the carb top; slowly turn it upside down until the float seats the needle. At that point (before it compresses the spring loaded ball) the float seam should be parallel with the carb top. Measuring (side view) the seam, in the middle of the float, I want the drop measurement to be 1/4" more, when I now turn the carb top back (as if re-assembling the carb). If the drop is too small, it slows down the fuel flow in the bowl. If too much, it can "hang" in some corners and cause the car to stumble. I hope this helps. Keith@Averill
From: Dave Weitzenhof
1. The primary jets have more effect on cyl 2 & 3 than on cyl 1 & 4. The secondaries have more effect on 1 & 4 than on 2 & 3. Therefore, if 2 & 3 are rich compared to 1 & 4 (plug check after clean-cut, etc.), lean primaries or richen secondaries, and vice-versa.
2. A long time ago, before the widespread use of EGT sensors, I very successfully used a seat-of-the-pants trackside method of setting the over-all degree of richness. I would warm up the engine to operating temp, and then immediately run it to ~3000 rpm, let the rpm stabilize, and then open the throttle wide open for ~1 second. If the engine died or hesitated for more than ~1/2 second, the jets were too lean and needed to be richened. If the engine just barely hesitated and then revved cleanly, the jets were just right. If it picked up smoothly with no hesitation, the jets were too rich. All of this assumes no major carb or other engine problems. This really did work quite well.
Kill Switch