1974 128 SL Coupe build project

Door seals, rear window seals, from McMaster Carr

Identified this vendor from the X forum, finding a plethora of useful products available on line. Previously successful with the JC Whitney solution for last Bertone project, this time went with McMaster as an appropriate size for the rear window seals weren't obviously available at JCW. From the Purchase Order image below, here's what worked quite well for your future reference:

1/8" Edge, 7/16" Bulb width, 25 feet for the rear windows.

1/8" Edge, 5/8" Bulb width, 25 feet for the doors.



Snipped with tin snips, and set with large rubber mallet.
 
Bosch Electronic Ignition

Next on the docket, install aforementioned distributor and electronics in place of the Ducellier points ignition. The Ducellier has a vacuum *retard* system, currently disabled. Coupe is difficult to start in cold conditions, and stumbles until warm. Also exhibits slight detonation under load at mid-rpms when warm. Hoping the Bosch improves both issues. First order of business, refresh distributor.

 
Next on the docket, install aforementioned distributor and electronics in place of the Ducellier points ignition. The Ducellier has a vacuum *retard* system, currently disabled. Coupe is difficult to start in cold conditions, and stumbles until warm. Also exhibits slight detonation under load at mid-rpms when warm. Hoping the Bosch improves both issues. First order of business, refresh distributor.


Watching!!l as I would also like to perform this mod....did you bought this from Midwest?...
 
Bosch electronic ignition distributor tear down

Following the process well documented on the forum, the unit appears serviceable. Reluctor / coil section will require some heat, and perhaps a mechanical puller. Haven't broken anything.....yet. Distributor coil, ballast resistor, and Bosch coil all measure within spec. Prior to disassembly, distributor did not turn freely. Cleaning, scotchbright pad, lubrication should resolve.

Likely going with a simple HEI unit affixed to fabricated aluminum heatsink, more compact that the larger stock Bosch box.

 
Finned heat sink module...

The late model Lancia Betas use the GM style HEI module attached to a finned aluminum heat sink, you might want to go that route.

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Bosch Electronic Ignition upgrade

Replaced Ducellier points distributor with Bosch system, HEI chip on a modified heatsink. Result is a smoother initial throttle transition, less abrupt. Points system was quite hair trigger.




Happily was able to reassemble the distributor, which was gummed and seized. Now fitted with OE Bosch rotor, cap, and wires. Yet to connect vacuum advance, need to find an in-line fitting for the hose between the Alquati intake and brake booster.

 
Also notable: stock steelies from new Fiat 500's fit. Below with a 185/55/15 Firestone.


I've looked all over the Internet for some info on this, and just randomly stumbled over this post!

Did you take clearance measurements? I took the tape measure out to mine and was coming up with about 5.25-5.5 from the hub face to the rear strut depending on rim size (strut kinda angles, ya know).

All of the specs I'm finding for 500 wheels are like 5.08-5.5 backspace which just wouldn't cut it.

So, does the SL have more (backspace) room than my sedan? Or are these steelies a different offset/backspace than the other ones I was looking at?

Any info is much appreciated. I'm about to pull the trigger on some Monzas from Mark Allison, I just want to make sure I don't have more options than I thought.
 
DCNF & Ignition tuning

Don't know the difference between sedan and coupe strut clearance. The good news is it's a cheap experiment, you can find steelie takeoffs with good rubber from new 500s for $125. Suspect it would work, worst case you add spacers. Meanwhile -



Symptoms: hesitation at 2-3k rpm. Idle mixture screws inconsistently effective. Occasional stalling.

Work done: siphoned float bowl, cleaned significant silt/rust that undoubtedly accumulated from the ‘driving old fuel tank clean’ technique. One of the air bleed adjustment screws was frozen with adjustment slot broken. Eased that out with a padded vice grip, cleaned up with tap and die and cut a new slot. Once that was in order reviewed all jets. First pass they looked clean, though upon reassembly discovered a microscopic bit of debris in one of the idle jets. DCNF now working quite well, metering perfectly.
Also tuned up the distributor – highlighted the pulley markings with yellow paint, re-set timing to appropriate advance.
There may still be a minute vacuum leak, between the carb base and Alquati manifold. To be addressed later with grease or gasket sealer.
Also, discovered leaking left front caliper seal. Refresh kit on order, along with vacuum T fitting for the intake to get the distributor vacuum advance functioning.

 
Stud kit, caliper rebuild, tire balance, vacuum advance

After about 5000 miles, Yoko S Drives on BWA's were well out of balance, 25-33 grams worth on 3 of the 4 wheels. Solved the freeway speed vibration. Concurrently, added a Midwest stud kit. And rebuilt a left front caliper that had been seeping. Pedal still too soft, will re-address with another bleeding session. And corrected the brake res supply lines per SteveC advice awhile back.




Installed "T" vacuum fitting 3/8" & 1/4" barbs to accommodate Bosch distributor, fitting installed in Alquati manifold. Vacuum advance definitely working, smoother driving, but a bit of detonation perceptible, will need to back off the advance 2 degrees.


 
Need L&R uprights aka knuckle / spindle

In an effort to replace both front wheel bearings, discovered extraordinary historic handywork. Someone likely broke the wheel bearing retainer attempting to disassemble, perhaps did not have access to the correct tool. Then re-assembled by welding half of the remaining retainer to the upright!

And did it to both sides of the car. Therefore, I need a set of good 128 uprights. Thanks in advance to anyone out there who might have these.

 
That is some really nice work... wow.

I have several spares but am on the other side of the country. If you can't find any locally (or close by) let me know and I'll dig some out.
 
What a nice car!!! and what a great project!!!!

cant wait to see updates!!!!! and wish i can find one as well for my self :wink2:


Best of luck!!

Serg
 
fiats!!

good to see a local address for another physco fiat nut case.
haven't been to the fwd thread area of the forum til now. good to know we are still here, west coast side.
I used to have a 128 sl that got towed away before I could do any thing with it. I've have had an enormous amounts of x1/9 in my life but the 128 was a love never learned.
good job so far!!
I also am in the bay area and any thing you need let me know
mikemo90*aol.com

keep us exers on the other side of the forum, who, like me haven't strayed to the other side as of yet
 
Resolved!

Courtney, Serg, Mike -

Your support is greatly appreciated. Good news is, nearly immediately, a set of uprights appeared courtesy of Mr. D. Voss.



Results are forthcoming, as is a trip to Rodeo, CA for evaluation.
 
I couldn't believe my eyes when I saw the pic of the welded retainer... that is certainly one for the 'black' museum!

New hubs look like later model (post 1975ish?) units too (thicker steering arm) which are the preferred 'go to' item.

Looking good though... :thumbsup:

SteveC
 
Pulling the direct vac means you are advanced all the time, it's an old trick for lumpy cams, give the dizzy full(non-metered) vacuum at idle.

looking good
maybe you will have a yellow wagon in your collection soon
 
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