We Have Ignition

Last week I drove with my daughter to a cruise-in at the local Rock & Brews. Since the car had been sitting for several weeks while I shipped off my master cylinder, I had to fill the carb bowls using a pipette in order to start the engine. She fired right up and off we went. As soon as we got out on the main road, however, I noticed the engine started miss-firing slightly. If I held in the clutch the engine would try to idle then slowly die. But if I stomped on the loud pedal the car accelerated okay so I figured it was getting plenty of fuel. I figured it was probably spark related.

I have a manual choke which I have set up to mainly bump up the idle when the engine's cold and doesn't really choke off the carb. So I bumped up the idle a little bit so it wouldn't stall and continued on to the show since it was so close. When I got there I let the engine cool off a bit and then poked around a bit checking the obvious things like plug wires and the distributor cap. Nothing seemed out of whack.

Driving home things started to get worse. I had to raise the idle up to around 1200 rpm to keep it from stalling at lights. Engine vibration was increased and the exhaust note sounded different making it feel like she was only running on 7 cylinders.

My current ignition setup consists of an MSD 6AL control box coupled with a MSD Blaster 2 coil feeding a stock rebuilt distributor. I've been wanting to get rid of the stock points and go with something electronic for a while now--no time like the present.

I tore down the stock distributor to see what's what and found that my mechanical advance was set up to provide 30 degrees of timing. You can see it's using the 15L slot which gives 15 degrees off the camshaft, or 30 degree at the crankshaft. This is a problem since I've got the initial timing set at 12 degrees before TDC, meaning I have 42 degrees of total advance. It should be more like 36 total. Now, I could pull the distributor and rotate the shaft to use the 10L slot, but then I'd only get 20 degrees of mechanical advance, or 32 total. Not enough. This setup if fine for a stock engine that only needs 6 degrees initial timing, but my cam requires more. In order to use the 10L slot I would really need 16 degrees of initial timing, which might be too much.

Interesting side-note: I've been studying engine timing a lot lately so here's some of what I can remember. Engines require the spark to fire before TDC because it takes time for the fuel/air mixture in the cylinder to burn and you want it burned completely by the time the piston has reached the end of the power stroke. At idle, the cylinder pressure is low--there's not as much air in the cylinder because it's being choked off by the throttle. This thinner mixture burns slower, because there's less fuel and air than at higher rpm, which requires an initial timing advance. For a Ford 289 the initial timing is 6 degrees before TDC. However, a radical camshaft like mine will reduce cylinder pressure at idle even more, which requires more initial timing.

As the engine spins faster you need to fire the spark even sooner than TDC, thus a mechanical advance is used. Centrifugal weights are used to advance the timing on top of the initial setting. You can see them attached to the springs in the picture above. At idle the weights are retracted all the way and don't start to move until just above idle speed. As engine speed increases they swing out advancing the timing until reaching their maximum advance at around 3000 rpm.

There's a third factor in controlling engine timing and that's vacuum advance. At low throttle openings cylinder pressure is still low which requires more timing advance than the mechanical advance can provide. So a vacuum diaphragm advances the timing in high vacuum situations, as much as 40 additional degrees in some applications. Traditionally this vacuum canister was connected to manifold vacuum so as to provide this additional advance whenever high vacuum was present, even at idle. Eventually, however, engineers discovered they could reduce emissions at idle by using a ported vacuum source, which blocked any vacuum advance at idle.

I hooked my Mighty Vac up to my vacuum diaphragm and saw that it didn't start to move until 7" of vacuum and reached its maximum travel at 16. Since I'm only getting around 8-9" at idle this vacuum advance wasn't really doing much for me. I had it hooked to the ported vacuum source on my Holley, so as soon as I cracked the throttle it just barely provide any advance at all.

After a lot of researching I decided I wanted to switch to using manifold vacuum for my source. But this brought up a problem. If I simply moved the vacuum hose to the manifold source I would start seeing vacuum advance at idle. Since my diaphragm is just starting to move at 8" I would also see an additional few degrees of timing advance. This in turn would raise my idle speed slightly which in turn would increase my vacuum, which would then add more vacuum advance, and so on. This no doubt would make my idle very unstable. Not good.

To fix this you need a vacuum advance that is fully advanced at a value lower than your idle vacuum. So I need a diaphragm that reaches its max travel at 7" or less. Chevy made one back in the '60s for this exact situation, but apparently not Ford Motorcraft. Shelby totally bypassed this conundrum by using a dual point distributor without any vacuum advance. Great for performance but not so much for economy.

At this point I was ready to replace the points distributor with an electronic one. If I went with an HEI version I could eliminate the MSD box as well. My MSD's been mounted in the cabin on the passenger kick panel and it buzzes very loudly. If I can hear it over the exhaust then it's making too much noise. I could move it under the hood but the loud buzzing makes me feel like it's not working like it should be.

I decided to order a PerTronix D130700 Flame-Thrower billet distributor which comes with their Ignitor II module. Unfortunately it only comes with a non-adjustable vacuum canister, even though Pertronix makes an adjustable one. So I also ordered a Crane Cams 99601-1 Adjustable Vacuum Advance Kit that would hopefully work with my big cam.

In order to install the adjustable vacuum canister you need to remove the distributor shaft. I drove out the pins for the collar and the drive gear.

With the shaft removed you can remove the plates that cover the mounting screws for the canister.

Here's the new adjustable canister in place with the limiter cam in place. You can see that it interferes with the bushing so I'll have to leave it off. It's designed for a '60s Chevy distributor which is designed a little different, oh well. I can still adjust the vacuum level at which the canister operates but I can't limit the amount of advance.

Here's a shot of the distributor put back together and ready to go in the car. Installing it was straightforward but I had the hardest time getting the engine to fire. With a points distributor you can static time the engine by turning the crank to where you want the initial timing to be and then rotate the distributor until the points open. With an electronic distributor this won't work so all you can do is point the rotor at terminal #1 and guess on the rotation of the distributor.

No matter where I turned the distributor the engine wouldn't fire. So I began my troubleshooting looking for spark. I attached a spare spark plug to the coil and set it next to a ground. When I cranked the engine, no spark. I thought maybe the distributor could be defective to I looked for a way to test it. Pertronix says there isn't a way to test the Ignitor II but they provided a check list of what to check. The most important thing is that you should have 12 volts at the coil + terminal.

The factory uses a resistor wire to provide around 6 volts to the coil to help the points live longer. This wire was bypassed when the MSD 6AL was installed so I knew I had 12 volts but I checked anyway. That's when I found something peculiar. With the distributor connected to the coil I was only reading 2.6 volts. But if I disconnected the positive wire going to the distributor I then read a full 12 volts at the coil. WTH? I felt like the Ignitor II module was to blame. I could jump a ground to the negative coil terminal to induce the coil to spark only if the Ignitor II was disconnected.

After contacting Pertronix they agreed to send me a replacement module. In the meantime I figured I would order a chrome PerTronix 45001 Flame-Thrower II coil to replace my 10 year old MSD Blaster 2. With the new module installed I rechecked my voltage readings and was shocked to still see only 2.6 volts at the coil with the Ignitor II connected. Unbelievable!

At this point I was totally lost. First, I thought maybe I was getting a bad ground from the distributor through the engine block so I ran a jumper wire to what I assumed was ground on my starter solenoid. Stupid me, there is no ground there so when I tried to start the engine I ended up sending a full 12 volts straight to the body of the distributor. There was a loud pop and the wire I was holding got instantly hot and tried to weld itself to the vacuum canister before my knee-jerk reaction pulled the wire off. Close one.

I then tried running a jumper to an actual ground but that made no difference to my voltage reading. So I made a quick trip to the local parts store and picked up a relay. I was hoping that for some reason my coil wire from the ignition couldn't supply enough current for the Ignitor II and was dropping the voltage. And it worked! After wiring up the relay I was getting a full 12 volts at the coil even with the Ignitor II connected.

Now when I tested for spark it worked. It only took me a few tries with the distributor turned to different positions before the engine finally fired. Hallelujah!

After finding junk in the fuel line and carb and then replacing the carb I could finally do some fine tuning. I used a pair of springs from the vacuum advance kit to give me full mechanical advance by 3000 rpm. I set the initial timing at 12 degrees and with the new distributor's 24 degrees of mechanical advance I got the full 36 degrees at 3000 rpm. I then plugged in the vacuum advance hose to the manifold vacuum port on the carb. Right away the idle rpm increased from the extra timing so I dropped the idle speed back down to 850 and checked the timing. At idle the timing was about 38 degrees before TDC. Obviously the engine likes the increased timing since the idle speed increased. When I disconnected the vacuum advance the idle speed dropped to the point of almost stalling so it's helping.

The Search for Top Dead Center

I wanted to check my marking for top dead center on the harmonic balancer since I'm pretty certain it's not original and might not be accurate. I purchased a Competition Cams 4792 Top Dead Center Stop from Amazon.

I screwed this into the #1 cylinder in place of the spark plug. I had already removed the rest of the plugs so the engine would spin easily. Then I slowly turned the crankshaft pulley counterclockwise to roughly 20 deg after TDC and screwed in the piston stop until it contacted the piston.

I marked the balancer at the pointer with a piece of tape. Then I turned the engine in the other direction (clockwise) until it hit the stop again at about 20 deg before TDC and marked the balancer with a second piece of tape.

Now I could remove the piston stop and turn the crankshaft until the pointer was halfway between the two pieces of tape. The was now my true TDC. You can see the pointer is off by about 1.5 degrees so I needed to move it over. I only had to elongated one of the two holes on the pointer to put it in the correct position.

Good Carb, Bad Carb, Part 2

After having problems getting the engine to idle, and eventually finding junk in the fuel line and the Holley carb, I installed a new Edelbrock 1405 Performer 600cfm carb from Amazon. The carb drops right into place on top of my 1" spacer but the hookups are little different from the Holley.

I picked up some new 3/8" hose for the fuel line since the Edelbrock only has a single feed while my braided line is for a dual feed. The new carb came with a cheap plastic see-thru filter which was perfect to replace the defective chrome filter. Eventually I'll look for something that looks nicer but this was the cheapest way to get the carb hooked up. On the Holley the EGR connected to the rear but on the Edelbrock it connects front and center. I needed a longer hose to reach the EGR valve on the passenger side valve cover (upper left corner) so I just used the same 3/8" hose. To the left and right of the EGR connection on the carb are the two idle mixture screws, and next to them are the two vacuum ports. The left port, which is above the throttle plates, is ported vacuum, while the right one supplies manifold vacuum. Edelbrock recommends trying the manifold vacuum port for the distributor advance if you run a big cam so that's what I'll try.

The throttle linkage connected easily; I made sure that I had full travel before the pedal hit the floor. The return spring bracket from the Holley didn't work so I picked up a cheap Spectre Performance 4708 Throttle Return Spring Bracket for $8.10 from Amazon along with a Dorman 59207 Throttle Return Spring assortment for $6.84. I mounted the bracket on the intake manifold in an existing hole pulling from the rear. The springs come very close to the choke linkage at wide-open throttle so I may have to try something different.

Here's the passenger side where the manual choke cable attaches. The Holley had a bracket for attaching the actuating cable but the Edelbrock just has a hole and I didn't want to just bend the wire around the choke lever.

I bent a dogleg in the wire so it can't fall out, but I can still get the wire through the lever coming in from the side.

After double-checking all my new connections it was time to fire things up. I cranked the engine for a few seconds and then looked to see if fuel was filling the filter. Check. I cranked the engine for about 10 seconds to fill the carb bowls. Then I pulled the choke, pumped the pedal once and she fired right up! It idled a little too slow with the choke and when I tried to open the choke a little the idle slowed down too much and it tried to stall. So I kept my foot on the gas pedal until it warmed up enough to idle on it's own. When the engine warmed up all the way it was idling at 1000 rpm so I lowered it down to 850 and adjusted the idle mixture screws to get the fastest idle without being too rich. The only other adjustment I made was to screw in the fast idle screw one full turn to see if that would help with the next cold start.

The next day she started right up and the cold idle worked much better. I drove to the store and back I am amazed at how well the engine runs. The Edelbrock runs smoother than the Holley ever did and it's practically straight out of the box.

There's Hair in My Fuel

After installing the new distributor I finally got the car started but it still didn't idle very well. The exhaust tone even sounded different. I tried to adjust the idle mixture screws but something wasn't right.

The procedure for adjusting the idle screws on a Holley requires a little finesse. Before starting the engine you turn the idle mixture screws clockwise until they are fully seated, and back them out 1.5 turns. This is the recommended starting point for tuning. My Holley 4150 has 2 screws on the primaries, some have 2 more on the secondaries. Start the engine, let it warm up, and then you can begin adjusting the idle mixture.

Adjustment can be done 2 ways. First, turn one screw in until the idle slows and then back it out until you get the highest vacuum reading. Then, back the other screw the same amount. If the idle increased you should lower it back down and repeat the procedure starting with the other screw. The second method ignores the vacuum reading and you adjust the idle mixture screws to get the highest rpm.

The problem I ran into was that turning the driver side screw had no effect on the idle speed or vacuum. In fact, I could turn it all the way in which should cause the engine to stall, but it didn't. The passenger side adjusted just fine though. Holley says ineffective idle mixture screws are indicative of a blown power valve, which would dump extra fuel at all times. I'm not sure that a blown power valve would only effect one side of the carb but it's an easy replacement.

Holley power valves are rated based on the vacuum that they operate. The stock valve is a 6.5 which requires an idle vacuum of 13" or higher to function properly. The correct power valve # should be half your idle vacuum, otherwise it could open too soon, and in worse cases open at idle. In my case, I'm only getting around 9" of vacuum at idle so I've known for a long time that my power valve is wrong, so this was a good time to replace it. I ordered a new 4.5 power valve from Amazon for less than $7. A week later it's $13.84, WTH Amazon?

Since I had to remove the primary metering block to replace the power valve I figured I would drop the main jets down from 71 to 70 since my spark plugs looked a little dark.

Here's the primary metering block from my Holley 4150. You can see the power valve screws in from the back side of the jets. What I wasn't expecting to find was a 6" hair coming from one of the passages. It looked like a strand of hair but it could have been a fine synthetic fiber. I tried to gently pull it out but it was stuck. I determined it was the port for the idle mixture screw and when I removed the screw the hair pulled right out with a big clump at the end.

The screwdriver is pointing to the passage where the hair came from. The idle mixture screw is removed and screws in from the side (the bottom in the picture). When I straightened out the hair it was about a foot long. I can't imagine how it got in there and I don't know if it came from Holley that way. I have removed this metering block once before and it seems I would have noticed this hair before.

I swapped the jets and the power valve and buttoned up the carb. After priming the engine fired right up but I could tell right away that nothing had changed. Fudge. It still wouldn't idle and the driver's side idle mixture still had no effect.

At this point I felt that the carb must have a blocked passage, especially since I already found some junk in there. I'm not too confident in my carb rebuilding skills so I felt it was best to just buy a cheap spare carb and rebuild this one later. I decided to buy an Edelbrock 1405 Performer 600cfm for just over $300 shipped.

When the new carb arrived I began removing the Holley. I started by disconnecting the fuel line and draining the fuel. When I pulled off the Mr. Gasket chrome fuel filter I noticed something wrong--it rattled when I shook it. If a filter rattles then it's loose inside which means fuel is leaking around the filter material. I looked in the outlet end and saw something was blocking the passage so I used a paperclip to try and pull out the obstruction.

Several plastic/rubber chunks came out, WTH? The one piece is curved so it's probably the seal around the edge. This kind of junk would cause total havoc with the smaller passages in the carb. When I drained the Holley fuel bowls more junk came out.

The larger pieces in the center of the blue cap are about 1/8" in size. No wonder the engine wouldn't idle. So the Holley needs a full tear down and rebuild. I'm glad I bought the new Edelbrock.

Door Alignment

Most of the body panels on my car are pretty darn straight, except for the passenger door. I've been meaning to look into this since day one but never got around to it, mainly because I can't open the passenger door very far when it's in the garage.

As you can see the door stick out at the bottom...

But goes in too far at the top.

As you can see the center part of the door where the striker is sits flush. My thinking was that if I adjusted the lower hinge only, I could push the bottom of the door inward and the door would pivot on the striker causing the top to come out.

The front of the door was already flush with the front fender so I didn't want to have to adjust the top  as it involved 6 bolts holding the top of the fender vs. 1 bolt on the bottom. But when I tried to adjust the bottom hinge I found I could only move the door in about 1/8" before the hinge ran out of adjustment. This meant I had to adjust the top hinge which was going to screw up my fender alignment. Oh well.

When I was done moving the hinges the rear edge of the door looked pretty good.

I couldn't get the entire trailing edge to sit flush since the angle at the top of the door doesn't quite match the rear sheet metal, but it's close enough. However, now the front fender was out of whack.

It wasn't as bad as I thought it would be, but I had to remove the kick panel to access a single nut keeping the fender from moving that 1/8" or so that I needed.

I'm pretty happy with final fit.

Packing Heat

Early Fords, and probably most other old cars, had a very simple heating system where hot coolant continually flows through the heater core. When heat is needed a trap door is opened allowing air to flow through the core and into the cabin. This works great as long as the heater plenum seals are in perfect condition. Otherwise, hot air seeps into the cabin even when the heater is off. On my car the plenum sits under the dash where it acts like a mini radiator, roasting my feet in the Florida heat.

Here's when the hot water from the engine leaves the intake manifold on its way to the heater core.

Here's the heater valve I bought that will let me shut off the flow through the core. It was advertised as having a 5/8" thread. And while it is indeed 5/8", that's not how pipe thread is measured. The old blue elbow is 1/2" npt, while the new part is only 3/8" npt. So I had to make a trip to the hardware store to buy a reducer.

Here's the new heater valve in place. Now my feet will be much happier. If necessary it only takes a few seconds to pop the hood and open the valve.

Master Of Cylinders

From day one my brakes have been quite disappointing. While every component of the braking system has been replaced, albeit 10 years ago, there are still issues that need fixing. To start, my lumpy cam only gives me 8" of vacuum at idle. This is a major problem since I have a power brake booster which requires a minimum of 15" to operate correctly. The only time my engine generates enough vacuum to properly operate the brakes if when the car is moving and I let off the throttle. Then I get only one application of the brakes before losing the power assist. This means at speed I have decent stopping power, but at low speeds I have to really stand on the brake pedal. Not safe (or fun) at all -- every quick stop was essentially a "panic" stop. I was all set to install a vacuum reservoir which would store up vacuum and give me longer braking assist, but then my booster failed.

While driving around the neighborhood the engine began stalling every time I applied the brakes. It didn't happen while sitting still, but once moving (and building up a vacuum in the booster) the engine would stall as soon as I hit the brake pedal. Luckily I wasn't too far from home. To isolate the problem I plugged the vacuum line running from the intake manifold and the booster. I've driven it with no power assist and made dozens of stops and the engine hasn't stalled once.

To troubleshoot the brake booster you hook up a vacuum pump to it, apply a vacuum, and step on the brake pedal. You're supposed to get 2 or 3 applications of the brake pedal before using up the stored vacuum, In my testing I only got one. I'm guessing that there is a leak in the booster that only manifests itself once I've built up vacuum and then applied the brakes. Maybe this is the only time the booster diaphragm moves, which would explain why I don't have a vacuum leak in the garage. Makes sense to me, I guess. Anyway, the booster is around 10 years old.

I decided to drop the idea of a power brake booster and go with a new master cylinder designed for manual disc brakes. It turns out master cylinder sizing is much more complicated than you could imagine. If the piston is too big then the line pressure may be too low requiring lots of effort at the pedal. And if the piston is too small then the line pressure will be fine but the pedal travel may bottom out. Wilwood makes a tandem master cylinder with a 7/8" bore that should be perfect for my application.

As you can see my existing master cylinder is almost hitting the shock tower and is partly covered by the export brace. Removing the booster will move the new master cylinder over 6" rearward, making access a lot easier. Unfortunately I'll have to rebend the brake lines since they'll never match up with the new position.

Here's the new Wilwood in place. It came with an adjustable push rod so I had it in and out several times getting the push rod the proper length. If I had been smart I would have worked on the brake lines now before bleeding the master cylinder. Hindsight... The front line goes to a distribution block before continuing on to the front wheels while the rear line goes to the SSBC proportioning valve.

This Wilwood is really a piece of art. I splurged on the polished version for an extra $50. Before being installed master cylinders need to be bench bled. Wilwood supplies the kit to do it (even though Summit let me order a second kit). Basically, you fill the reservoir with fluid and work the piston in and out. This forces fluid and air bubbles through the hoses and back into the reservoir. The only problem is that the little red fittings are cheaply made out of plastic and leak. Once I started this operation I had two slow leaks to contend with. Now you see why I should have bent the brake lines first. My attempt at reusing the existing brake lines didn't go so well either. The two lines are both less than a foot long and bent fairly easily. I first cut some wire the length of each brake line and then shaped the wire to the fittings on the car. Then it was just a matter of bending the lines to match the templates. However, I couldn't get a good seal when connecting the lines to the master cylinder. When I pulled them off I could see that the flares were poorly formed. So I ordered some new lines along with a nifty little tubing bender--what I should have done in the first place.

Here's the new lines bent to match my wire templates. I bought 12" lines, which were a few inches longer than the originals so I'd have plenty of room to make some nice defined bends. The old ones looked like they were hand formed--really sloppy.

Here's the new lines in place--no leaks so far.

UPDATE: July 2017

Wouldn't you know it, 3 months after I get the new master cylinder working and Wilwood issues a recall. They emailed me a shipping label so all I had to do was box up my old (new) one, ship it to them, have them repair it and ship it back to me. The guy on the phone said it would only be a 2-day turn around once they received mine but it ended up taking 2 weeks. So with shipping both ways it was closer to 3 weeks of down time. My son helped me take the old one off by crawling under the dash to disconnect the brake pedal.

Wilwood wanted me to remove all fittings and the pushrod before shipping it back so I used my combination square to measure the pushrod. When it came back I reinstalled the pushrod and adjusted it to the correct length before putting it back in the car. Last time I bench bled the master cylinder before I installed it but this time I figured I'd try bleeding it on the car. It sits very level in the car so I didn't think it would make a difference. It was definitely easier, I had my daughter pump the brake pedal while I watched the bubbles get purged.

Last time I lost a lot of brake fluid while trying to bend and connect the new brake lines, but this time the lines knew where to go so I hardly made a mess. Bleeding the brake lines using the two-person method of pumping the brake pedal while opening the bleeder screws can prove to be quite tedious so I looked for an alternative this time.

I bought a Motive Power Bleeder with an adapter that clamped on the top of the Wilwood master cylinder.

This bleeder is designed for you to pour a quart of brake fluid in the pressure tank which will then fill the master cylinder as the level goes down. At first I couldn't picture how this wouldn't just fill the reservoir up to the top and make a mess when you took it off, but then I realized that the volume of air in the reservoir would remain constant, so the fluid level would never change as long as the tank had fluid.

After all this, the swap was successful. The brakes work great. So far...