Our Cars Demand Attention-Part II

[304065]

Well I suppose this is entirely my fault.

Life, as many of our members know, can get in the way of properly enjoying one’s SWB 911. (That, and buying a one owner 1989 944 Turbo S and entering it in the preservation class at the Parade…)

It being July and with the schedule freed up a bit I determined to pull ‘065 out of storage in the Fortified Barn and have a drive.

Restarting the engine after sitting for over a year was a simple matter and I had good oil pressure within seconds of turning the key. Once oil pressure was established I connected the ignition and the car started and idled like a top.

However, on the road it was different. For some reason I am getting a profound ignition stumble at or around 4000 RPM. It might be the advance weights sticking, although the advance should be all-in by that point, or it might be that I am using a Bosch Blue coil. (As I have bored everyone here with previously, the Bosch Blue coil has high primary resistance which means that it charges more slowly, and may not be delivering enough energy at high rpm. I will look into replacing it this weekend with one of my many coils from my collection.) I'm using the Blue coil because I'm lazy-- I have a complete original 1966 ignition system for the car-- ballast resistor, NOS coil, original straight bakelite plug insulators. . .and the insulators go open circuit when they warm up and the ignition breaks up, which is why the Factory went to the right- angle version in 1968. When you replicate ancient systems you replicate ancient problems. Anyway, when I took the show stuff off after the last show, I put the Blue Coil on just to get home. . . I have, variously, a Red Coil, an MSD Coil, an original coil, a MSD 6AL-2, a complete Bosch MFI setup and a Hot-Spark (copy of the Pertronix Ignitor II Hall-effect igntion). I think I'll try the Hot-Spark with the Bosch Red Coil-- at 1.5 ohms it should draw about ten amps, this will be a fun experiment.

More disconcerting is this: for whatever reason I cannot maintain a firm brake pedal. I have bled the brakes three or four times and the pedal still is soft. This happened coming out of storage: I do not know whether there is a leak caused by mice, doing what mice do, or whether the seals on the master cylinder have dried out, allowing air into the intake, or whether a caliper seal is somehow admitting air.

I ordered a new ATE master cylinder (none of the URO bits where brakes are concerned) but will try one more bleeding with the pressure bleeder to see if I can resolve it. I replaced the flimsy 7.5 mm bleed valves on the front calipers with Russell speed bleeders having an 8mm ATF hex wrenching feature, these are a lot easier to use. Maybe the bore of the master cylinder rusted due to disuse and tore up the O-ring, this is all I can think of (but maybe this failure mode is a apocryphal and never really happens)

In any event I was able to get the car to go around the block and was rewarded with dense oil smoke coming from the driver side defrost vent. An oil leak from the valve covers has put oil into the heat exchangers which is burning off and causing a cloud of smoke worthy of the invasion of Normandy.

Of course when I restored ‘065 I insisted on using the original six bolt cam towers for originality. I do not suppose I can claim undue surprise given that the precise same failure mode which resulted in the cam towers going to 11 bolt in the late 1960s is now visiting itself on me. If you replicate ancient systems you replicate ancient problems.

Did I mention that my cheap flare wrench Gave up the Ghost? I have ordered a HAZET which will be willed to my descendants, that's the only way to amortize the cost. Maybe that's why people give their HAZET stuff to their grandkids, just to justify the initial cost of ownership?

I drove a friend's 2020 992 Carrera S the other day, all 443 horsepower of her. And while a fine machine in all regards, I wouldn't trade it for Butzi's original, pure design, which still puts a smile on my face every time I drive her. Plus the 911 has a bigger engine compartment.

So stay tuned for the repair photos here!

[ibmiked]

"I have ordered a HAZET which will be willed to my descendants, that's the only way to amortize the cost."

Please never stop contributing here.

[Scott A]

I enjoy reading your work.
But must advise. My brother had a heat exchanger that was smokey. And had some oil in it.
And CAUGHT FIRE!!

He got fire out. We hate fires+cars.

[G69]

Take a crow-bar to your wallet and spend $75 on a genuine Pertronix.

I had a 'Hot-Spark' fail on me and it was very character-building.

[stephers]

You all own nice 911's worth a fair chunk of change and you are complaining about the cost of good Hazet wrench Time to stop buying at Harbour Freight and if you think Hazet
is expensive, see what a Snap on tool cost

[Scott72]

What do you think of the Turbo S? I had a 1988 Turbo S Silver Rose with 50K on it - all stock but a set of rims. Didn't like it. Not sure why but always felt like it was 2 seconds from blowing apart.

[ecostellodo]

this is the FAQ from pmb about soft brake pedal after bleeding:

https://www.pmbperformance.com/faq-c...ns.html#169964

[304065]

Well the parts have arrived. Genuine ATE master cylinder, ATE Gold (DOT put the kibosh on Blue in 2013 and boy is THAT annoying), new bleeder hose and a set of Russell Speed Bleeders for the rear calipers (11mm across the flats).

The HAZET wrench is on its way, enjoying a First-Class seat from Remscheid on Lufthansa. In the mean time I scored a Park Tool (you know, the bicycle tools company) for about eight bucks. They were out of HAZET crowbars.

Scott: The Turbo S is an absolute engineering masterpiece. It's the most neutral handling car I have ever driven, hard as a rock M030 suspension and a K27/8 turbo with absolutely violent power delivery. And it even has air conditioning that works, unlike the Panting Squirrel version found in the 911 that was not adequately resolved until the 996. Open the hood and there's just about enough room to pour in a cup of water. . .when they converted from NA the engineers used every cubic centimeter of available space. As such, any mechanical work requires a significant disassembly of the car. This particular car was owned by my neighbor, a former Naval Officer and Submariner, who bought it new in '89 off the lot. I managed to take Fourth Place in the Preservation Class at Boca due to the rare color, glacier blue, almost silver, with a blue gut. I love the angularity of it and the box flares are so. . . 80s!

I miss the 80s.

[Scott72]

I miss the 80's also. Some of my favorite cars came from it. Let me know if you need the timing belt tools down the road. I still think I have all of the ArnnWorx tools from when I did it myself.

[304065]

Update:

The speed bleeders were not only the wrong length but the wrong thread. Back to Bezos & Co. they go!

Laziness, being the mother of invention, I used a Stahlwille 8mm bleeder tool on the front calipers WITHOUT having to remove the wheels, and old track trick for bleeding between sessions. Of course the Fuchs had more clearance, this was tight.


Through more pumping I was able to get a "better" pedal. There was enough improvement that I determined to NOT pull off the splash guard.

I think if an O-Ring were torn the pedal would go all the way to the floor.

So I turned to the ignition. After digging in the Fortified Barn for half an hour, I found my electrical stash under a pile of old tax returns. In it were a Bosch Red Coil (1.5 ohms) and a Carrera Coil (0.4 ohms) and an original 1965-dated 911 Coil with screw terminals. (This is NOT the correct 1966 coil as that one had the flat terminals). I also found the Hot-Spark and installed it in a spare, restored cast iron distributor that Ed Fall did for me a decade ago.

The only way to do this is with a long 3/8 extension and a 13mm crows foot wrench, it's a breeze. Have your magnetic retriever handy, you will need it.

Here's the old distributor coming out. I pointed the rotor toward the radial line and lined up the timing mark with the notch on the blower housing.



The hot-spark comes with a rubber boot that goes through the hole in the side. Since the circular insulator is gone I can use a modern orange cap which might fit a little tighter. This will all be fixed up with some vinyl tubing, this was just the initial test run.



Timing was simple- I set idle to 0 and at 5500 RPM was getting 32 degrees, as designed. (Peter Dawe told me not to use more than 32 degrees total timing due to the detonation-prone design of the 2,0 heads. When a guy who worked for ANDIAL tells you something it's best to do it, immediately if possible.)

Now, which coil? [Warning: Electrical Engineering Geek Section Ahead]

I reviewed the manual for the Hot Spark and it says you shouldn't use a coil that is less than three ohms primary resistance. Here's why they say that: the semiconductor in the unit can only handle 4.2 amps of current. (12.7 volts system voltage divided by three ohms = 4.2 amps, by Ohm's Law). Truthfully, this isn't much better for high-rpm performance than the old Kettering-style points-condenser-battery ignition that '065 came with from the Factory. The Hot-Spark eliminates points bounce, and it takes care of dwell automatically, which is a plus, but in terms of its ability to switch high current (7-10 amps) it won't do it. This is probably due to HEAT more than anything else-- they actually give you a little envelope of heat-conductive paste to apply between the base of the Hot-Spark and the base plate in the distributor.

For example if I were to use the Carrera Coil (0.4 Ohms) at 12.7 volts system voltage it would draw 31 amps. Now you say, "I don't remember seeing welding cables in the engine compartment of my 3,2" you're right, the Motronic Control Unit and the off-board drivers (Like a Bosch BIM137) will limit current to 10 amps and have a big heat sink plate attached.

And the Bosch Red wasn't going to work either, at 1.3 ohms this would give you 9.8 amps, which could be great with another setup, but even Bosch said, on the side of the can, to use a 1.8 ohm ballast resistor with it. This is probably because it can't reject enough heat during continuous operation at high current-- the lower resistance is for starting with a ballast resistor cutout circuit (just like the one found in the SWB cars).

So who steps up to the plate but the ancient 1965 coil, at 2.1 ohms resistance, will give 6 amps. That's enough to charge the coil a little quicker and not burn up the Hot-Spark. I once emailed the guy and asked him how much current it could switch, I think he said 7 amps, YMMV.

If you're interested in the math behind these conclusions here's a really boring thread on the subject from nine years ago.

http://forums.pelicanparts.com/porsc...discharge.html

or if you are a Coil lover, this one here:

https://www.early911sregistry.org/fo...d-NOS-SWB-Coil

[END ELECTRICAL ENGINEERING GEEK SECTION]

So, did it work? You bet it did. The Bosch Blue Coil will be retired to 36hp VW duty.



Even have remnants of the original coil sticker on there! (I'll look for a "modern" coil" with the right Impedance and Primary Resistance later on)

Next issue: smoke coming from the vents. I'm going to get under today and investigate the valve cover leaks. . hoping that's all it is.

Enjoy your Sunday!