Sharpening My 1978 CS1

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opus10583
Posts: 861
Joined: Tue May 03, 2011 7:13 am
Your car is a: 1978 CS1
Location: Westchester County, NY

Sharpening My 1978 CS1

Post by opus10583 »

After a fairly extensive review of this site I still have several questions concerning bringing my car closer to its design optimum.

I am not looking to make a Miata-fighter out of a 33-yr old FIAT. I looked at Miatas, I looked at S2000s, I even looked at a heavily breathed-on S3 'Vette" convertible: I wanted and bought a small Italian spider (I looked at a lot of rats). But I want what Lampredi and Pinin Farina intended, not what Nader and Claybrook did to it: I want to bring it to as clean a state of tune as possible within stock equipment parameters.

First: I know it will never be quite right until I drop in some HC pistons. Unfortunately that will have to wait until I recoup the Impetuous eBay Purchase-Tax... (Apparently, "surface rust" means "holed-through suspension pickup points", in an obscure West Ohio-criminal dialect.) I hope to have the car back in my hands at the end of next week, I fully expect I will not.

Second: 1978 CS1 49-state 1800, Pertronix Igniter replacing the stock twin points in a stock distributor. Stock 32 ADFA Weber on a stock single plane manifold. All emissions test-gaming equipment removed as far as I can tell and if anything's left it will be available, free + shipping, to anyone who wants it as soon as I can wrest it free. Soon to have a FIAT BS/CS 4-2-1 manifold/downpipe combo plugging into a NOS Abarth AS/BS exhaust system: This is a done deal and I care for no debate.

A: Ignition Timing

I understand my car should be set to 0deg static advance and has a mechanical distributor that should max out at 36deg advance somewhere near 3500rpm. I also understand this is purely an emissions testing compromise and that people commonly set these cars to 5-15deg static advance yielding then, as I understand it, 41-51deg full advance.
  • 1) How isn't that level of total advance harmful to these engines given that it's said 36deg total is the design target? (...Wimpy CR?)
    2) Can anyone provide a source for the stock advance curve for this year and model?
    3) Is there a source for the stock advance curves for the various AS, BS, CS models and 132A1-series 1800s fitted to other models?
    4) If I understand correctly I would rather want 5-10deg static advance and a curve that maxes out at 36deg total, but with what sort of profile?
    5) Is "re-curving" the distributor as easy as it seems; adjusting stops, swapping weights and springs (can I swap in the parts from an earlier distributor); or is my impression of a Priesthood that must be appeased correct?
B: Cam Profiles and Timing

I assume the timing and grind of the cams in my car are, again, dictated by emissions testing workarounds rather than efficiency and drivability.
  • 1) Can anyone provide a source for the profile and timing of the stock cams for my car?
    2) Is there a similar source for various AS, BS, CS models?
    3) Source for the global 132A1-series engines?
    4) Is there a commonly accepted timing reset of the stock cams to recoup some degree of efficiency and drivability?
C: Carburetor

I'm looking to source "the usual suspects", but I don't want to overcarb at this point. Again, and until the previously mentioned eBay Tax is paid-off and I can do HC pistons, I just want to make sure all the emissions test cheats are removed and remediated and the piece that's on the car is functioning as correctly and efficiently as possible.
  • 1) I've seen here a few pictures of carbs with various ports plugged off, does anyone have a schematic depicting which ports, on the carb and/or manifold, should be plugged and what was at the other end of the circuit that's been severed (and where to get those port caps)?
    2) Was the 32 ADFA used on the 132A1-series engine in any market other than NA and is there a source for how they were jetted and set-up?
    3) The subject's been tangentially approached in another recent thread, but my question here is rather: Ignoring the goal of gaming emissions tests, what would be the proper baseline jetting and emulsions tube specifications for a 32 ADFA on a 1978 CS1 1800 with ignition and cam timings set optimally as well?
...I've tried to be detailed in describing my intentions and understandings, and specific in my queries, and I appreciate any insight and explanation anyone here can offer toward achieving my goal of running a CS1 1800 as God and FIAT intended.

TIA,
Mark
Last edited by opus10583 on Mon Jul 04, 2011 2:31 pm, edited 1 time in total.
...Yes; I know what it means: Fabbrica Italiana Automobili Torino.

DOLCETTO: 1978 CS1; 10:1, DMS, 4-2-1...
ANDIAMMO: 2012 500 ABARTH

Acquista il Biglietto; Prendere la Gita! - Hunter S. Thompson
baltobernie
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Your car is a: 1973 Spider [sold]
Location: Baltimore, MD

Re: Sharpening My 1978 CS1

Post by baltobernie »

Hello Mark, and Welcome!
Congratulations on doing your research and setting achievable goals for your new car. The bad news is, the 78-79 engines are the poorest-performing of the 19-year model run. The good news :D is that you can go from 80 HP originally to 120 HP without giving up everyday drivability.

High Compression: You probably realize that adding CR doesn't add a lot of power, but the sound and feel of a desmogged HC motor is terrific. The car always feels like it's on a short leash, wanting to run off after something. No matter that the absolute power is less than a Corolla, the driving experience of a vintage, euro-spec Italian sports car is unique.

Ignition:I have the same ignition setup as you, with a Bosch blue coil. The Pertronix coil is also supposed to be pretty good. I had my dizzy reworked by Advanced Distributors in MN. I sent him this graph,

Image

... along with a worksheet he provides, and he did the rest. I don't know the initial and total advance of my engine. We just let the dyno determine the best setup.

Intake/Exhaust:There are of course limitations of factory parts, but the 4-2-1 exhaust manifold and a single-plane 1800 intake is a good combination.

Camshafts: You're on the right track to avoid wild profiles for street use. The OE cams are pretty aggressive as is. You may be able to achieve your goals simply by modifying their timing with adjustable cam wheels, which you'll need in any case. The "first level" cams from our usual suppliers have plenty of lift and duration for what you're trying to achieve, if you choose to go that route. If you want a better idle, use only the HP intake, and keep the stock exhaust. Also take a look at your crankshaft pulley now. It probably has three grooves for the smog pump, etc. Find yourself a single-groove pulley, either OE or aftermarket, so you have enough clearance to apply a degree wheel and time your cams.

Carburetion: The 32/36 electric choke Weber seems to be the odds-on choice for street engines. The 34 also has its fans.

All this assumes that the internals of the engine are in good order. I'd suggest a cold and hot compression test and an examination of the spark plugs before undertaking an engine makeover. Good Luck!
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opus10583
Posts: 861
Joined: Tue May 03, 2011 7:13 am
Your car is a: 1978 CS1
Location: Westchester County, NY

Re: Sharpening My 1978 CS1

Post by opus10583 »

Thanks!

I want that high CR sound. Half the reason I bought another Spider, 30 years later, is the sound that they can make. It's also why I want the factory 4-2-1 and Abarth system, figure I'll be about 80% there.

Nice tip on the crank pulley, less mass as well, I'm sure. (Lightened flywheel waits until I replace/rebuild "bad throwout" transmission.)

Where did you get the data for those advance plots? From the looks of that it seems I can just twist in the 10deg static and not worry about the total, but then I'm guessing Marelli Plex is a system that has a knock feedback circuit... I'll have to look that up.

Any opinion on 34 DMS vs 34 ADF? Anybody?

Thanks,
Mark
...Yes; I know what it means: Fabbrica Italiana Automobili Torino.

DOLCETTO: 1978 CS1; 10:1, DMS, 4-2-1...
ANDIAMMO: 2012 500 ABARTH

Acquista il Biglietto; Prendere la Gita! - Hunter S. Thompson
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124ADDHE
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Your car is a: 1974 Spider Amalgamation with C40 Solex
Location: Salmon Arm, BC, Canada

Re: Sharpening My 1978 CS1

Post by 124ADDHE »

Dont know about the ADF but the 34dmsa is a great carburator with a mechanical secondary, I ran one for a few years on an engine quite similar to your and it was very stong compared to the stock 78 carb. Dual carbs sound much better though, you would probably be missing the mark with a single carb if sound and torque curve are your concerns....
Regards,
Keith Cox
1973 124 Spider
1973 John Deere 500c backhoe
1987 Jaguar VDP
2013 passat tdi
2015 cherokee
baltobernie
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Your car is a: 1973 Spider [sold]
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Re: Sharpening My 1978 CS1

Post by baltobernie »

I don't remember where the advance curves came from ... maybe Mira? I agree that the profiles look similar, and may be achievable without modification.

I'd suggest caution on dual carbs, only because you're committed to the OE header and Ansa exhaust. While you'd certainly have a nicer sound, I don't know about power improvements, given the restrictions of the stock exhaust.
Sunracer

Re: Sharpening My 1978 CS1

Post by Sunracer »

opus10583 wrote:Thanks!

I want that high CR sound. Half the reason I bought another Spider, 30 years later, is the sound that they can make. It's also why I want the factory 4-2-1 and Abarth system, figure I'll be about 80% there.

I have an Abarth system they sound great

Nice tip on the crank pulley, less mass as well, I'm sure. (Lightened flywheel waits until I replace/rebuild "bad throwout" transmission.)

I have an aluminum crank and WP pulley-made a noticable improvement

Where did you get the data for those advance plots? From the looks of that it seems I can just twist in the 10deg static and not worry about the total, but then I'm guessing Marelli Plex is a system that has a knock feedback circuit... I'll have to look that up.

I have a Marelli Plex, it is similar to the factory electronic distrib used 79 and up. I doesn't have vacuum advance though, it is a little shorter than the stockers because of this, and it has no sealing o ring around the base. It relies solely on the gasket. As a result, it often leaks, At some point I will get a grove machined in mine so I can use the standard o ring.

Any opinion on 34 DMS vs 34 ADF? Anybody?

I have run the following carb set ups on a modified 2 liter: 34 ADF, 32/36 (think it was the DFEV), Single 40 DCNF.

I have owned cars with the 34DMSA. Based on all this I think you should seek out a 32/36, it was the best short of the DCNF, but the DCNF is a lot of trouble to jet and install and I just don't think the improvement is worth it. At that point go to IDFs.

There is a fellow named Terry Terizakis he custom builds the factory elec. distribs with a custom curve. Starting from scratch I would really consider this as a first choice for a distrib., rather than a stocker DP with Pertronix or electronic distrib. See if someone has a nice, leakings tired distrib buy it and send it to Terry T. Add on a high powered coil like the MSD Blaster2 or Pertronics Flamethrower. You can fool endlessly with this stuff, which I know can be fun, or go to Terry and bolt on a good carb. With your exhaust system, your car will be vastly improved. Give it a good valve adjustment, go tight on the specs. while putting on a new timing belt and rev the piss out of it : ) PB

Thanks,
Mark
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opus10583
Posts: 861
Joined: Tue May 03, 2011 7:13 am
Your car is a: 1978 CS1
Location: Westchester County, NY

Re: Sharpening My 1978 CS1

Post by opus10583 »

Thanks All!
124ADDHE wrote:Dont know about the ADF but the 34dmsa is a great carburator with a mechanical secondary, I ran one for a few years on an engine quite similar to your and it was very stong compared to the stock 78 carb. Dual carbs sound much better though, you would probably be missing the mark with a single carb if sound and torque curve are your concerns....
Trying to stay within my First Year Budget projection of $10k. I'd blocked out Year Two for 'now what's?'
...Thought I'd have thousands of miles on it by now, have about 250.
baltobernie wrote:I don't remember where the advance curves came from ... maybe Mira? I agree that the profiles look similar, and may be achievable without modification.
I'll try there. [No Joy. ...And I do not care for their interface.]
I'd suggest caution on dual carbs, only because you're committed to the OE header and Ansa exhaust. While you'd certainly have a nicer sound, I don't know about power improvements, given the restrictions of the stock exhaust.
I'm not opposed to dual carbs "as a thing or a person", I don't really want to make this car into that car.
Sunracer wrote:I have run the following carb set ups on a modified 2 liter: 34 ADF, 32/36 (think it was the DFEV), Single 40 DCNF.

I have owned cars with the 34DMSA. Based on all this I think you should seek out a 32/36, it was the best short of the DCNF, but the DCNF is a lot of trouble to jet and install and I just don't think the improvement is worth it. At that point go to IDFs.
Given all that I've read, and the current price and availability realities, it looks like a Spanish 32/36 is going to be the choice. I'll be looking for jetting info for them
There is a fellow named Terry Terizakis he custom builds the factory elec. distribs with a custom curve. [...] See if someone has a nice, leakings tired distrib buy it and send it to Terry T.
Is he working for the CIA now? I've found references that end about four years ago [Terezakis]... Then nothing.

Would that be a 79-85 distributor, then?
You can fool endlessly with this stuff, which I know can be fun, or go to Terry and bolt on a good carb. With your exhaust system, your car will be vastly improved. Give it a good valve adjustment, go tight on the specs. while putting on a new timing belt and rev the piss out of it : ) PB
That, plus fiddling with the cams (can't I just jump a tooth or two on each cam?) is all I want to do!

...At least until February 2012.

Thanks again to everyone who's offered help!

Mark
...Yes; I know what it means: Fabbrica Italiana Automobili Torino.

DOLCETTO: 1978 CS1; 10:1, DMS, 4-2-1...
ANDIAMMO: 2012 500 ABARTH

Acquista il Biglietto; Prendere la Gita! - Hunter S. Thompson
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