Lotus 61 Restoration Project
Part Four

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WELCOME to "Part Four". Pure and simple "We Are Stylin'!!" In starting this part with the engine let me remind you that I didn't overhaul the engine in this restoration. I built a new engine a year ago that was/is very strong. All I needed to do to prepare it for the 2007 season was hand lap the valves. So without further ado, here we go.....

You'll recall back in the hydraulic section I said perfect brakes were better than 25% more power and lousy brakes. I meant that. I use a term I call "Free Horsepower". It has nothing to do with the engine; it deals with making the car absolutely perfect, thus enabling you to extract more from it without the latest, greatest, expensive and (historically illegal) "chrome muffler valves, roller bearing piston rings or 360 degree overlap cams".

I learned a valuable lesson early in my career. I was on Denny Harrison's pit crew back in the mid 60's when he raced a Porsche 904. That gave me access to, and the opportunity to 'look over the shoulder of' and learn from a Meistro: Al Cadrobbi. Al even helped me build an engine for my '57 Speedster. I was in mental turmoil. I wanted the three "Big 'C's" (cams, compression and carbs) and Al was spending my money on things to keep the engine alive rather than making it fast. It turned out being fast, and decades later I can see the wisdom of his efforts. I raced that engine HARD for two years and it never failed me once.

You climb into your "Go-Fast Special" and take off. There's just a little too much gap between the brake and throttle for effective heal and toe downshifting. There's a heavy, sluggish gearshift lever. The brakes are good, but not spectacular. Your seat isn't as comfortable as you could make it. Your mirrors don't stay adjusted as well as you would like. And on and on.....

Everything that interrupts your concentration, everything that you have to consciously think about while your doing it, anything that's not as perfect as it could be is slowing you down. So, I'm "preaching to the choir" you say. Yes, its true. So here's what you do.....

Fabricate a new gas and/or brake pedal and make that heal and toe downshifting a natural movement of your foot. Work on that gearshift linkage until it requires no thought... it becomes an extension of your arm and shifts like an automatic transmission. Work on those brakes until they are as perfect as humanly possible. Make the seat an extension of your butt; something you could sit in for the 12 hours of Sebring and not get saddle sore.... THAT's "Free Horsepower". That's what will get you ahead of the guy in front of you because now you've fixed all those things that he is still dealing with. Now he's behind YOU(!!), wondering where YOU got the extra 25 horsepower.

Engine: I use a Cortina based engine in the Lotus, and I build my own engines. Sure, I could call Jay Ivey, give him my credit card number and $8,000.00 later have the most powerful (and legal) 40 hour TBO (Time Between Overhaul) formula Ford engine available in the world. But until I see that scout from Maranello scouring the pits looking for Schumachers replacement.... I'll just be out there for the fun of it.

My engines are strong; as good as any built in a home shop. If you ask me I'll even happily tell you everything that's in it. It's even "Monoposto" legal rather than the (more powerful) SCCA standards for formula Ford. (Remember the HMSA motto: "what it was, not what it could have been".) If I have a 'speed secret', it's already been stated above... Build it as close to "blueprint specs" as possible. Build your engine to stay together and survive. To get that bottle of champagne in the winners circle you first have to finish.

Gearbox: Considering the neglect they receive they are really hearty, stout little parts of the car. They take all that abuse from engine "mismanagement" and improperly synchronized gear shifts, get their oil level checked (but never changed) at every engine change (do you Really have to change gearbox oil?) and otherwise get completely ignored until they finally tire out and break. Let me ask you: when was the last time you sat next to your gearbox and 'lovingly' wiped the oil and grease off it and spoke kind words to it for the wonderful job its doing?

The Lotus uses a Hewland Mark 6 gearbox. It has four forward and one backward and per regulations an 'open' differential. I use a 9:31 ring and pinion, and with sixteen individual gear sets I'm able set up the ratio's uniquely for each track. (As an example; for Sears Point I use a first gear that could be used for 'stump pulling', and for a fast track like Willow Springs it gets a first gear good for 85mph.)

My philosophy has been to stack first gear for the slowest corner and fourth gear to be redlined 100 yards from the braking point on the longest straight. In a "perfect world" I'll have a 1,000rpm drop first to second, 750rpm drop second to third, and 500rpm drop third to fourth. I've polished the rails and trimmed the 'detent springs', and now it shifts like pushing a steak knife through warm butter. Back to the concept of 'free horsepower': that gearshift lever is literally an extension of my hand and shifting/selecting gears has become a totally 'unconscious' process: it just "happens". If you ever asked me I would have to think about it before I could tell you what gear I was in at any given place on the track.

Since the Hewland is a "crashbox" (no synchro's) I don't use the clutch except for engaging first gear to start off from a standstill. (AND during spin recovery so I can keep the engine running).

A "weak link" on the Lotus is the design of the frame relative to the way it suspends the gearbox. On most formula cars, the gearbox and engine mounts put the drivetrain in 'compression'. With the Lotus the gearbox is under 'stress', being pulled 'away' from the engine. This often results in the gearbox case cracking where I've indicated in this old photo.

To "cure" this deficiency I've fabricated a truss. Its simply a 7/16" all-thread rod that bolts to the front of the gearbox case on the upper right side and to the right side transmission mount. Once the drivetrain is installed in the car I adjust the tension on the rod, thus the rod is now under stress relieving the stress on the gearbox case.

While cleaning and inspecting the gearbox I saw that the clutch release linkage had a badly worn bushing. Here is a typical use for 'home machinery': making a new bronze bushing. A couple hours at the lathe and I've not only saved myself $19.00 (plus shipping/handling and a weeks wait for delivery) but I've got a new part that's better than original. Old bushing on right and new on left. Tech/Safety Tip: To quote Norm Abrams (New Yankee Workshop) "Always wear these: safety glasses".

The completed and rebuilt clutch release linkage.

Once again, I hope everybody is enjoying this story. I know I am... I even know the outcome!!

Fuel: Its a pretty simple system. I have an ATL cell with about 3.5 gallon capacity. Fuel is drawn into a one pint accumulator then electric fuel pump and on to the carburetor. Formula Ford is restricted to a single Weber 32/36DGV series carburetor, and with a little internal work and dump tubes they work quite well.

The cell sits right behind me in a semi-enclosed tray behind the seat. Its sitting on a non-skid foam pad and is secured by a leather strap bolted to the floor and firewall. In the top of the cell is the fuel filler, fuel outlet and vent. The vent has a check valve that prevents fuel from leaking in the event the car goes upside down.

The fuel cell vent tube (arrow) extends twelve inches above the cell; preventing fuel from vacuum venting at high speed. I also use the vent for filling the cell. An all-too-common fault of fueling formula cars is the lousy placement of the fuel cap: virtually guaranteeing you will overfill the cell and spill fuel all over the seat! In my case I pump fuel into the cell through the vent pipe. I remove the fuel cap so I can monitor the fueling progress and shut off the electric pump (filling the cell) when its full. It takes about three minutes to fuel the car, but I've yet to spill a drop.

Axle donuts: The half shafts on the Lotus connect to the gearbox stub axles with rubber/metalastic couplers: also called "donuts". Being the precurser to CV joints they work quite well. The 'negative' thing about them is they can break. Should the 'donut' fail it allows the half shaft to flail; damaging the half shaft and everything it comes in contact with. Depending on the vehicle speed at the time it could be catastropic. (Writers note: this is one item where I strongly disagree with Monoposto: which requires donuts unless you can "prove" that CV joints were original equipment on a specific car. A CV joint does absolutely nothing to improve car performance yet they are monumentally safer than the donuts.)

To remove a donut it must first be "shrunk" slightly and must be "shrunk" slightly to install reinstall. Some folks simply use a large hose clamp. Nope... not me! I had to invent a pair of donut compressors! My donut compressors 'collapse' all six sides of the donut evenly by tightening or loosening the nuts on the all-thread rod.

To prevent damage during a 'donut failure' there are (commercially) available "axle savers". These bolt to the half shaft and stub axle through the donut mount holes and prevent the half shaft from flailing if the donut breaks. I made mine.

Interpreting the photo, one of these plates is bolted to the half shaft and the other bolted to the stub axle. The 'pin' in one plate goes through the hole in the other plate. If the donut breaks, the pin is trapped in the other plate, preventing the half shaft from flailing.

Here you can see the plate with the pin bolted to the outside of the donut and half shaft. The other plate is bolted to the stub axle and donut. The compressor is still in position. If the donut breaks you can see how the stub axle would be 'trapped', preventing it from flailing.

Once the engine and gearbox are assembled they are mated together. Tech tip: I've made a simple set of 'legs' that bolt to the engine mount bolt holes on the block. These allow me to stand the engine on the floor without it falling over and also provide a stable platform when mating the gearbox to the engine. Note the casting number on the side of the block: "681F". This is a Cortina block. An uprated (Pinto) block would be casting number "711M". This engine block is also the basis for the Lotus twin cam engine and the Cosworth "BD" series engines.

Formula Ford has a 'bad rap' for breaking crankshafts and/or connecting rods. While the cast iron crank and short rods are contributory; one of the main (and overlooked) "culprits" is really flywheel strikes, mainly caused by "off-track excursions". The bottom of the flywheel is usually exposed under the car and may even extend below the line of the frame. In my (formula Ford) career I've broken two cranks. One was from faulty metallurgy in the crank and the other most likely from a flywheel strike. After that first crank failure I constructed a skid plate that you can see in this old photo. It bolts to the bottom of the frame and has about 1/4" clearance between the plate and flywheel. From the number of (deep) scratches on it I would say its been a worthwhile investment! (Note also the safety wire to the oil pan drain plug.)

As much as I love working on race cars and building race engines I absolutely DETEST "oily hands" and grease under my nails! The other thing I hate is oil dripping on the floor. Tech tip: a simple solution to leaking oil fittings is using your old rubber gloves. Here you can see how I've cut the fingers off an old pair of gloves and stretched them over the oil line fittings. It works! (Note: the 'brass fittings' on the oil lines convert the "BSP" {British Standard Pipe} fittings to "AN" fittings making hose fabrication monumentally easier, plus you can use 'pushlock' fittings that NEVER leak).

Another 'handy-gadget' in "Carls magic toolcrib" (hand made of course.... who would expect me to "buy something" that I could spend a day making!?!?) is this simple flywheel lock. Installing and torquing a flywheel, and installing a clutch disk and pressure plate were never easier. Made from 1/4" steel and a couple hours on the mill, and another tool is born.

Finally the engine and gearbox are mated. The engine stand removed and motor mounts and starter installed. We're ready to lift it into the car. Here's another view of the gearbox 'truss', and the donuts with the compressors installed. (Because its unpainted {don't have a CLUE why I've never painted it} many folks think I've got an "SCCA" aluminum head. Nope.. its cast iron).

careful.... Careful.... CAREFUL.... Easy now! "All that space" is suddenly, completely consumed and filled! A little 'body English' on the tach drive to clear the starter solenoid, pull it back so the (dry sump) oil pump clears the frame and doesn't tear the shoulder belts, a little lower and rock it down to mate the transmission cradle, a little lower and insert the motor mount/frame bolts, and IT'S DONE!!

Five bolts to secure the motor mounts and transmission cradle and the drivetrain is a 'fixed part of the car'. Next step was several hours connecting oil lines, wiring and half shafts; and rechecking a zillion nuts and bolts.

Following this I removed the head and hand lapped the valves. (WHY didn't I do this while the engine was out of the car, you ask? I have a 'phobia' about a disassembled engine AND car. Yes, I'll do it if necessary, but I just don't want engine parts getting in/on the car and vice versa. For me, its easier this way). But, the head goes back on and gets torqued, then the intake manifold gets bolted on. In inspecting the exhaust header I discovered a crack (VERY common on formula Fords) so I welded it and installed the exhaust. At last everything in the drive train is finished and I can relax for 15 minutes before the next (unending) step in the restoration process. Here's our progress thus far....

I'm going to leave you here. All that's left is connecting the fuel lines, adjusting the valves, installing plugs and connecting the plug wires, and filling it with oil. After that I can "strike a match" to the fuel and see if it will run!

In the next part I'll get into the chassis alignment. I don't know yet, I may devote an entire part to this. In the meantime...... it's REALLY getting its personality back and looking, feeling and "smelling" like a race car!!