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Discussion Starter #1
Can someone confirm for me if Alfa used different throttle bodies for the early rod/linkage type throttle, versus the 1992 and later cable operated throttles? Or are they the same throttle body, but with different hardware?
Mille grazie...
 

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there are actually 3 throttle bodies listed in the S4 parts book.
Two makers, one was dellorto and the other, uhm, I can't recall at the moment, maybe solex ...but there were definitely different manufacturers.

the difference listed in the parts book was between Automatic cars (PN 60555452), throttle rod cars (PN 60519110) and throttle cable (PN 60565066) cars.

If it helps, my early S4 with the throttle rod uses this one, a dellorto:
dellorto.JPG

why the question?
 

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Discussion Starter #3
Thanks Dom-- I knew I could count on you for the P/N's! So the answer is yes, the later cars with cable operated throttle use a different TB. I sort of suspected that.
I am seriously considering converting my '91 (with the rod/linkage) to the cable operated throttle. I'm going to meet here in town with Conedriver soon, since he has a '92 Spider with the cable type throttle body, and review what parts I would need for the conversion. I also realize the accelerator pedal assembly is different.
Even though I bought my Spider new, I have never liked the rod/linkage feel or action. My wife Irene used to have Giallo, a '93 CE model with the cable throttle, and I much preferred that feel and linear action. BTW, Giallo has long since returned to Italy (Sicily), to a collector with an Alfa/Fiat /Lancia shop.
Mille grazie Amico... :D
 

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Be aware that someone here already did that conversion (Vin maybe?) and wished he never had started!
It was a nightmare apparently!
Do a search.
 

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Discussion Starter #5
Right... I skimmed through it, but maybe I should take another look. I do recall seeing the linkage rod across the top of clutch housing was a pain.... Thanks. That's why they make the Saws-All !
 

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Interesting project but really I find the throttle rod control on my car just fine.

Ideally you’d need to fit the exhaust manifold with the 2 bosses to take the heatshield ( the heatshield is only there to protect the throttle cable from the heat)
Plus I’ve not seen the cables for sale, so you’d have have one made, preferably a couple of them as one day that might fail.

Parts book lists further differences:
the pedal assy (obviously)
sourcing and fitting those parts alone will not be easy, methinks:
cable.jpg
air ducting
plenum
throttle body
Thermostat housing connection
intake manifold
some plenum hoses.

you might be able to work around some of those but it is changing an engineer's design for a rube goldberg one;)

one plus point with cable throttle is you can fit cruise control...someone here has done that too...JohnM I believe it was
 

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But Mad North-Northwest
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I seriously disliked the rod linkage on my S4 when I got the car, but after doing some work it's pretty good now. Few things you need to do:

1) Get all the play out of the system. The rubber bushing at the right side of the crank arm across the firewall is notorious for getting floppy. Beyond that the crank under the throttle can get play that can be improved with shimming

2) Get the rod lengths adjusted properly and ensure the pedal stop is set properly (too high and you won't get full throttle, too low and it'll stress the linkage). When things are set up properly that bushing end I mention above should be held away from the firewall about 0.25-0.5" by the long rod

3) Replace the spring on the left side of that crank arm (behind the cast exhaust tubes) with a significantly weaker one. It is way too strong and messes with the pedal feel. The throttle has a spring (and I believe the crank underneath it has a spring too) so the throttle will still close fine

All that will be a lot easier and cheaper than switching to the cable, and it'll work well when you're done.
 

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Thanks Dom-- I knew I could count on you for the P/N's! So the answer is yes, the later cars with cable operated throttle use a different TB. I sort of suspected that.
I am seriously considering converting my '91 (with the rod/linkage) to the cable operated throttle. I'm going to meet here in town with Conedriver soon, since he has a '92 Spider with the cable type throttle body, and review what parts I would need for the conversion. I also realize the accelerator pedal assembly is different.
Even though I bought my Spider new, I have never liked the rod/linkage feel or action. My wife Irene used to have Giallo, a '93 CE model with the cable throttle, and I much preferred that feel and linear action. BTW, Giallo has long since returned to Italy (Sicily), to a collector with an Alfa/Fiat /Lancia shop.
Mille grazie Amico... :D
My Motronic has rod linkage and it works great. Well, except when I broke one of those cheap plastic ends off last week. Now replaced with metal.
 
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Discussion Starter #9
I'll have to look at the entire scope of work involved, yes, then I'll decide. But the bottom line for me is that I just like the progressive feel of the cable better. As for the parts, I would wrap a reflective insulation sheath around the cable where it passes above the exhaust. And, if this would involve anything more than a different throttle body and pedal assembly, then I would probably back off altogether. I just went through the injectors and all the fuel line rubber last fall, so I have no desire to pull that intake off again just for this idea. From what I remember of working on Irene's Giallo, I did not notice anything else different in the ducting or intake system between our two Spiders. Once I go over George's Spider and compare it to mine, I'll know whether or not this is worthwhile.
Tom, I do appreciate your comments also here, regarding fine tuning the linkage and rods. It just makes sense to optimize that mechanism, if I'm going to keep it. I have new Spruell-sourced HD motor mounts to install, plus rebuilding my driveline and tranny mount, so I'll take a good look at the bellcrank under the intake while I'm in there. Frankly, I haven't checked the condition of those firewall bushings for a long time, either. Thanks Dom, for the pedal assembly illustration, too.
We'll see... thanks to you all for this feedback!
 

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I'll have to look at the entire scope of work involved, yes, then I'll decide. But the bottom line for me is that I just like the progressive feel of the cable better. As for the parts, I would wrap a reflective insulation sheath around the cable where it passes above the exhaust. And, if this would involve anything more than a different throttle body and pedal assembly, then I would probably back off altogether. I just went through the injectors and all the fuel line rubber last fall, so I have no desire to pull that intake off again just for this idea. From what I remember of working on Irene's Giallo, I did not notice anything else different in the ducting or intake system between our two Spiders. Once I go over George's Spider and compare it to mine, I'll know whether or not this is worthwhile.
Tom, I do appreciate your comments also here, regarding fine tuning the linkage and rods. It just makes sense to optimize that mechanism, if I'm going to keep it. I have new Spruell-sourced HD motor mounts to install, plus rebuilding my driveline and tranny mount, so I'll take a good look at the bellcrank under the intake while I'm in there. Frankly, I haven't checked the condition of those firewall bushings for a long time, either. Thanks Dom, for the pedal assembly illustration, too.
We'll see... thanks to you all for this feedback!
Some day, I will tell you about my cable breaking experience and having to boost one from a parts car behind a repair shop to get home on a Sunday.😂😂
 

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Discussion Starter #11
Some day, I will tell you about my cable breaking news experience and having to boost one from a parts car behind a repair shop to get home on a Sunday.😂😂
:LOL: OK Pantera, and then I'll tell you about me finding a length of rope alongside the road, that I used to replace a broken fan belt! Over a couple of beers...
 

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:LOL: OK Pantera, and then I'll tell you about me finding a length of rope alongside the road, that I used to replace a broken fan belt! Over a couple of beers...
Sounds like a plan if we ever get past this COVID. I used to pass through your area several times a year.😂😂😂
 

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Discussion Starter #13
Alfisti are always welcome at our place. Bluegrass hospitality...
 

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But Mad North-Northwest
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Everyone knows that's why you always bring a cute girl along for road trips: so you can use her nylon stockings to replace the fan belt when it breaks!

But the bottom line for me is that I just like the progressive feel of the cable better.
I'm telling you, man: it's not the rods vs. the cable, it's that crazy strong spring on the crank arm. If you replace that with something more reasonable you get a much smoother, more progressive pedal.
 

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Discussion Starter #16
My own comments back some 7 years ago:
"Interesting... I was doing a search on this topic not long ago myself. It was sparked by my son's comments on how nice and smooth my wife's '93 Spider drove (cable) compare to my early '91 (rod). He said it made it easier for him to get used to the car (he's 17, did his first autocross last spring).

He also made the observation that there seemed to be some lost motion in my car's throttle rod linkage, and I checked it and he was right. Like about 1/2" play in the linkage. Lesson: when you're that used to a machine, sometimes you unknowingly adapt to some of the abnormalities that others, less familiar with it, will notice. So, check for excess play and adjust it out, then spray lube the rod ends AND the bushings on the firewall. That made a HUGE improvement in my '91, and Mike gave it the thumbs-up too! Now he enjoys driving mine as much as the '93.

Thanks also for the thoughts on converting to cable throttle. I was seriously considering it, but I now agree it's not really worth all the work and parts."
 

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Discussion Starter #17
And Vin's comments on that same thread:
"SS4 is right that early 91's had the linkage style. Late 91's and on had cable.

All S4 atuomatics have cable as well.

I have an early 91 and changed from linkage to cable as I was told it was smoother.

I have to say, it might be a bit smoother but not that much. I kept the maintenance up on the linkage so I think that helped.

I would not recommend this change to you.

There are a lot of parts that have to be changed including the intake manifold. More than I thought and also work needed on the inside of the driver footwell as well as on the firewall.

I suppose it would have been easier if the engine was out, but still would not recommend the change. Too much effort for not a lot of payback.

My $0.02

Vin"


Food for thought... I can't imagine the intake manifold being different, but now two fellows here have mentioned that. That would be a deal killer for me. Not worth it.
 

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Discussion Starter #18
Tom, you may have sold me buddy! I'll make some photos of the cable system parts this weekend, just to document what's there, but this driveshaft work, trailing arm bushings and mounts are the top priority now for my car. The throttle linkage work would not take that much time, as you describe it. Molto grazie...
 

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No prob. I just took the spring to the "assorted extension springs" section of the local hardware store and found something about the right length, but weaker.

The only challenge to the whole thing is getting the old spring on and off. It's pretty strong and you need to use some good needle nose pliers at minimum. But it's not rocket science.
 

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Be aware that someone here already did that conversion (Vin maybe?) and wished he never had started!
It was a nightmare apparently!
Do a search.
Yup, that was me.

Glad you found the post I made about NOT recommending the change.

It really was a lot of work with little benefit.

There are a lot of parts that need to be changed, including the throttle body. As I look back now, I get that feeling of "oh what have I gotten myself into this time".

Not only the throttle body, but also the outlet from the thermostat and the intake manifold itself is different as well as the gas pedal you already know of.

Here is a few pictures to help you decide to do your best to improve the throttle linkeage you already have. And there are more!

I rarely say this, but in this case, don't do it.

Vin
 

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