The Maestro's Quiz- 18 Sept 1996
Copyright 1997, by Harry Pellow, All Rights Reserved.

It has been quite a week at the Maestro's shop. First came a 1953 356 Pre-A, in for an Industrial engine swap, replacing it's tired, and still-ruining (barely) but all too valuable 1953 1500 Super, with a rebuilt, hopped-up, 1973 Military-Industrial Engine.

..... Then came a pretty nice 356C with the Dreaded European Heater System for its engine swap, replacing a sodomized Super-90, with a "C" Engine having all the proper European Heater Accessories, including the itty-bitty "carb heater" outlets that attach to the middle bolt of the Intake Manifold and shoot hot air to the carb. Even THEY were there.

..... The Maestro just LOVES working on European Heater System Engines. Hanging the Heater Boxes is sometimes more than just a Major Pain. The Muffler girdles are always cracked where the mount to the Third Piece. The third pieces studs are always just a little bit too short to take the girdle a decent washer and the nut. And the lower air shrouds hanging off each lower exhaust stud can be a real bit*h to install.

..... That done, Today at 3:56 pm, a 1957 Speedster, owned by a man we'll call "Steve" drove into the Shop.

..... The Speedster had a owner-overhauled (Steveahauled?) engine that hadn't been done too badly. The engine was of proper vintage for early 1957, having the Five Bolt Seal Ring, but instead of Single Barrel Solexes, had 40PII Solex carbs and, of course, a Big Bore Kit.

..... The Complaint: that when Steve drove the Speedster down to the 1996 Monterey Holiday in August 1996, (where, Ironically, the Maestro gave his Broken Parts Tech Session on Forensic Porsche Pathology), the Speedster Bucked and Backfired every step of the way! Down and back.

..... Backfiring. Backfiring. Backfiring. Driving Steve insane with every sound pulse. Along the way, during the weekend and on the way back, he had tried adjusting the Carbs every which way. But Nothing worked.

..... And boy, it sure seemed like the Carbs! Bad backfiring out of #3 cylinder (ain't it always that darn #3?), Some backfiring out of #2 but not as bad. Sure seemed like bad Solexes or worn throttle shafts.

..... But the Maestro never tries to do a serious Carb adjustment without first checking the Timing. So that's what he did. First.

..... He got out his ever-Faithful Sears Adjustable Timing Light and a 12 volt battery (to power the timing light, as the Speedster was still 6 volt). He hooked things up, signaled Steve to fire the Beastie up, and shined the Xenon Light of Truth onto the timing mark on the pulley.

..... The engine settled in, idling at 'bout 1800 rpm. Not surprisingly the timing was almost 20 degrees advanced. The Maestro revved the engine up past 3000 rpm. The timing went to 35 degrees and stayed there pretty steady.

..... "OK, I see a bit of the problem- said the Maestro. "Your distributor should have 30 degrees advance in it. Instead it has 35 degrees advance. At low idle, it's sitting at Top Dead Center and 35 Degrees at high rpm. 35 degrees is about as far as you want to go with your high speed advance with the gas these days, but the Idle timing is too retarded. You've got the Worn Original Distributor Syndrome.

..... How's about we put in an .050? That'll at least eliminate the Distributor as the possible Problem

..... Steve agreed. ANYTHING, ANYTHING just to make his formerly $90,000 Speedster, now $50,000 Speedster (maybe), RUN again! He was sick of explaining to all the potential buyers and the boys at Monterey why it backfired all the time and generally ran like poo-poo.

..... The Maestro, assumed the Position with his wrenches at hand and began.

..... With his Metric Adjustable Wrench on the crank pulley nut, he cranked the engine over until the TDC mark on the Pulley lined up with the Timing Mark on the Third Piece of the Case. Then he popped the Distributor cap, and surely the Porsche gods were with him, 'cause #1 plug wire was right where the rotor was pointing to! He had won the 50-50 gamble. This Time.

..... Then he disconnected the distributor's wire at the Coil, loosened the distributor clamp, and the Original Distributor just jumped out into his outstretched arms, eager to begin Retirement.

.....In went the New .050. Smoothly. Like it wanted to be there. Re-attach the plug wires, making sure the Rotor pointed towards the little notch on the distributor's body when #1 plug was about to fire.

..... That done, he cranked the pulley a quarter inch to the left to provide a guessed 5 degrees advanced. And gently rotated the .050's body until the points jussssst started to open. That's decent enough timing for initial fire-up.

..... The Maestro motioned to Steve to fire the engine up again. It fired up- no Brazilian banana oil on the points this time.

..... Again, the Maestro pointed his Xenon Light of Truth on the crank pulley and adjusted the .050 to give 'bout 33 degrees high Speed Advance. (beyond 3000 RPM). That resulted in some 6 degrees advance when idling.

..... So, the Maestro told Steve to try it out for a Test Drive and Answer the Perennial Question the Maestro asks all his Customers after he's done an adjustment: Does it Run Better? Worse? Or the SAME as Before? Steve was anxious to find out.

..... As Steve drove off, the Maestro heard a little backfire or two- and thought- Well, it might run a little better, but it's probably still got carb problems, and went to answer a nicely-timed phone call.

..... About the time the Maestro finished the phone call, Steve (remember Steve?) came back from his Speedster Run out testing the New .050 Distributor.

..... "Why it's absolutely AMAZING Maestro said Steve excitedly. It runs just like it should! Before I couldn't get it over 4500 RPM. Now, I can do 5500rpm!"

..... The Maestro tried out the Speedster too- and yes, despite a weak second gear synchro, it WAS MUCH better than before!

..... SOOOOO much better than before that it was Obvious to the Most Casual Observer that the ORIGINAL DISTRIBUTOR was the CAUSE of 93.56% of the Problem!

..... So: What WAS the problem with the Original Distributor that could imitate a set of bad Solexes, causing mucho backfiring, loss of power, erratic idling and a 4500 RPM rev limiter?

..... This is your Mission, should you decide to accept it: What the Hell was wrong with the DAMN distributor??? The Maestro's Quiz, What's Wrong With The Distributor- Part 2:

..... If you'll recall, Steve's '57 Speedster ran verrrry badly, backfiring back through the Carbs, wouldn't go faster than 4500 RPM, etc. As part of the Debugging Process, the Maestro replaced a mildly bad Original Distributor with a new .050, expecting only a mild change. He got instead a DRAMATIC change- the car suddenly ran Right! Turned out the Original Distributor was the CAUSE of most all the problems!

..... The Owner asked the Maestro what could POSSIBLY have been wrong with the Original Distributor that could have had such a Dramatically BAD affect on the Engine- imitating Bad Solexes so perfectly that Everybody at Monterey said surely the Carbs be bad.

..... (At first, the Maestro couldn't imagine WHY any Distributor in its right mind would want to impersonate BAD Solexes, until a Flash of Inspiration hit him:

..... OF COURSE- Clearly, after 100 Years of Auto Evolution Auto Parts have now evolved Self-Preservation! An Auto Part will apparently do almost anything, even impersonate Bad Solexes, to avoid going to Auto Part Hell- the Junk Yard, and eventually, the Blast Furnace.

..... But ifin an Auto Part successfully masquerades as a bad something else, the something else gets replaced! Not it.)

..... The Maestro grabbed the still warm Distributor, plucked from the engine's womb, and eyeballed it. It looked like a Rebuilt Original Distributor.

..... By rotating the shaft, he aligned the Rotor to point to the Notch in the Distributor's body- #1 cylinder. Then, he slowly rotated the shaft back and forth, watching the points open for #1 cylinder. They opened up just like they should. No Surprise here.

..... So he rotated the Distributor's shaft further clockwise to open the points for the Second Cylinder in the Firing Order. Which, since the firing Order is 1-4-3-2, would be? That's right, Number 4 Cylinder.

..... He eyeballed the points on Number 4 cylinder and, and, and... they opened just like they should. This is getting a little BORING said the sometimes Impulsive Center of Higher Reasoning.

..... So he rotated the distributor to the next cylinder in firing order and that is? Now, let's not see all the same hands. That's right- the Dreaded Number 3 Cylinder.

..... Again, he eyeballed the Points whilst turning the shaft clockwise, and waited for the cam lobe on the Distributor to open the points. And waited for the cam lobe to open the points. And waited. And waited. Until it was Intuitively Obvious to M. Casual Observer that the points WEREN'T OPENING for #3 Cylinder! Nor, as it turned out, for #2 cylinder either!!!

..... So, HOW can an Original Distributor fail in such a way as to do THAT- fire 2 Cylinders and not fire two others, I hear you cry incredulously!

..... That's Part 2 of the Quiz! KEEP THE 356 FAITH! The Maestro THE MAESTRO'S DISTRIBUTOR QUIZ- the Conclusion

..... The next day the Maestro took the Devilish Distributor over to Jay's for his look-see. The Maestro was desperately seeking solution as to why TWO lobes of the Distributor opened the points fully, but two others barely moved the points at all. Somewhere, there was a "point gap" of, ideally, sixteen to eighteen-thousandths of an inch missing.

..... When the Maestro eyeballed the Distributor's Cam with his UN-aided Eye (glasses off), he found no evidence of a "pass" having been worn through the Mountain of the lobes.

..... Jay was interested enough in the cause to get out his Dial Indicator with the Magnetic Base which he attached to the Distributor's convenient Cast Iron body (try THAT on an .031's Aluminm Body).

..... He placed the dial indicator on the circular part of the shaft where the rotor seats. And rotated the shaft.

..... The Dial Indicator showed .020" variation!

..... Twenty Thousandths runout is enough to open the points on one side of the Distributor to .016"-.018" but NOT move the points on the other side a'tall.

..... Wonder how that happened, thought the Maestro. Maybe a whack from a hammer during a "rebuild". Or a drop onto a concrete floor?

..... So, you might want to add Bending, Twisting, Dropping to the things on your Checklist that you DON'T want to do during a Distributor overhaul!

..... And:

KEEP THE 356 FAITH!
 

 

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