Fulvia S1 subframe measurements

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piggdekk
Posts: 47
Joined: 19 Sep 2020, 12:07

Fulvia S1 subframe measurements

Unread post by piggdekk »

Hello,
I'm restoring a Zagato to its former racing glory and I'm facing some issues with the engine subframe. It's not rusted at all and pretty solid but it has had a few close contacts in its life. The frame is marked 818330 so it must have belonged to a 1.3.
Anyhow, I'm taking measurements and comparing them with the SAT. The main issue are the height offsets. The offset between the front mounts and the mid monts is around 40mm. Based on the SAT should be 47mm. I just cannot see how it can have sagged on both sides by this much. Similarly the offset between the mid mounts and the rear mounts it's less than 18.5mm. Do You guys reckon that the SAT is accurate? how can I have 7mm difference? I'm planning on building a jig for it, but I struggle to see how I can bend it back to the specs.
many thanks
luca
Huib
Site Admin
Posts: 1778
Joined: 17 Dec 2008, 10:12

Re: Fulvia S1 subframe measurements

Unread post by Huib »

I have a stupid question. What is SAT?
piggdekk
Posts: 47
Joined: 19 Sep 2020, 12:07

Re: Fulvia S1 subframe measurements

Unread post by piggdekk »

Hi Huib,
I'm referring to the technical data sheets, see attached for the subframe. Very likely I'm using the wrong term.
thanks
luca
fulvia_technical_data sat 11-0020.pdf
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Huib
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Posts: 1778
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Re: Fulvia S1 subframe measurements

Unread post by Huib »

Aha. I call it the DT (Data Tecnici). SAT might be more correct. I wonder what SAT means. There is an error in the drawing you posted. I will collect some data and come back .

Do you by any chance live near Napoli Italy?

The reason I am asking is that my daughter is in Praiano (between Positano and Amalfi) having a problem with my Fiat Punto 1.4 16V and the 6 speed automatic. The gearbox warning light is on. Nobody seems able to solve that. She has to go to Monopoli in Puglia.
piggdekk
Posts: 47
Joined: 19 Sep 2020, 12:07

Re: Fulvia S1 subframe measurements

Unread post by piggdekk »

Hi Huib,
I am originally from that area, but 40km inland (Avellino). The mechanics I know would be too far. Beside, I live in Spain right now, so I cannot be too much of help.

Clearly hard to find a mechanic on sunday, but I have asked a few friends if they can point me to a good workshop. The largest FIAT dealer in the Salerno Area (probably better to drive to Salerno than back to Naples, and she can take the A16 Salerno-Avellino-Bari from there too), is this:
https://www.galdieri-fcagroup.it/conces ... t/officina
If she is in a rush I would contact them as they are very likely to have spare parts.
Should she have troubles communicating feel free to ask the mechanic to contact me at +34 609848889.

Good luck, Salerno is a nice and safe city far less chaotic then Naples, if she has to spend an extra day there she might not regret it.
luca
piggdekk
Posts: 47
Joined: 19 Sep 2020, 12:07

Re: Fulvia S1 subframe measurements

Unread post by piggdekk »

I double checked and my mates also suggest visiting Galdieri's workshop right outside Salerno. It's also very easy to reach:

https://www.galdiericarservice.it/

this is the address:

Salerno
S.R. 18 delle Calabrie km 62+173
Loc. Fuorni – Salerno
tel 089521661 fax 089521630
callcenter@galdieriauto.it

I don't mind giving them a call tomorrow if it can help.
luca
piggdekk
Posts: 47
Joined: 19 Sep 2020, 12:07

Re: Fulvia S1 subframe measurements

Unread post by piggdekk »

I'm thinking loud now on the subframe measurements, I could clearly be wrong.

Looking at the body SAT (or DT) the offset between the front mount and the rear mount is 95.5-64=31.5
On the fron mount the spacer that goes between frame and body is 21mm, on the back is 41mm. So there is a difference of 20mm.

For the subframe to lay flat the difference between the front mount and the rear mount should be 31.5+20mm=51.5mm (which is close to the offset that my frame has got)

Accoording to the frame SAT the offset is 18.5+47= 65.5. Either the frame isn't sitting flat, but why would they do that, or the SAT is wrong.
luca
fulvia_technical_data sat 15-0010.pdf
(106.09 KiB) Downloaded 38 times
piggdekk
Posts: 47
Joined: 19 Sep 2020, 12:07

Re: Fulvia S1 subframe measurements

Unread post by piggdekk »

Following the same math and including the height of the alloy suspension supports it turns out that based on the chassis measurements the offset between front and mid should be 43 mm, not 47, and the offset between mid and rear should be 8.5mm not 18.
I'm very puzzled now.
luca
Huib
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Posts: 1778
Joined: 17 Dec 2008, 10:12

Re: Fulvia S1 subframe measurements

Unread post by Huib »

OK, Luca My sister in law and her husband arrived. They are gone now and I am all yours again.

You are taking all those drawings seriously. Good. My compliments. It is important. Earlier this year we built extra tools to measure bodies and subframes. We went through all dimensions and made the calculations. That was in the work shop. I am not sure if I put every thing in the cloud. I will check that later. Step by step.

The drawing of the subframe is very clear and very good. One slight error. The arrows for the 2,5 mm at the rear mounting should be moved up one line. The 2,5 mm is the off set between center mounting and rear mounting. That would also be the logical way to put in the dimensions. There are also drawings in the S1 workshop manual and the AST foglie. (the same characters AST !?!?.) Somewhere there is a drawing where the dimension is entered correctly.

Also note that the reference line marked H.O on the drawing of the body is not the plane on which the center mounts of the sub frame are. I shall look for the off set later.

To help understand and feel the forces it is a good idea to try the following way of looking. Like with primates the weight is on top of the pelvis. The weight is on the upper wishbone. This is unstable and thus gives speed and flexibility. The lower wishbone just keeps the swivel up right.

The genius of Antonio Fessia went further. I like to look at the subframe as a mechanical computer. During the war many machines (to aim bombs or guns) were built which can be called mechanical computers with mechanical function generators and all. If you work on Lancia's it is very enlightening to visit a museum showing those machines. Fessia designed the front suspension around 1947.

The propelling computer unit consists of the two alloy towers, the three cross members, suspension and steering, engine and gearbox. The body is put on top of that with the two anchor points being the holes in the upper wheel arches. Those are the reference points. Make sure those are in exactly the right position. And the center lines of the holes must be vertical. Any deviation from vertical will come back as a caster or camber error. The large subframe is there to keep the propelling unit up right.

Do not take for granted that the dimensions of the body are ok on a Fulvia specially the flimsy coupé and even flimsier Zagato. Many had accidents in the past. Most if not all have been repaired badly. To allow the average body worker to do a good job the car would have to be completely disassembled and put upside down in a spiedo. And use the factory tools as shown in the tools book. Nobody did this of course. And very few if any outside the factory had the tools.

Other causes of bent and twisted bodies are: driving too long with bad sills, the tilted engine, hitting objects with the front wheels. Check, check and double check. If you repair sills it is a good idea to do that with the car horizontal. Weigh all the hardware that came from the doors and put the same weight in the doors when you fit them for testing.

A good test is to see what happens when you lift the car from the front of the fenders with the doors open. Stand in front of the car. Grab the front of the fender. Move up and down. The open door should not move different from the body. Some weld in extra supports. It is better to look for the metal fatigue and broken spot welds.
piggdekk
Posts: 47
Joined: 19 Sep 2020, 12:07

Re: Fulvia S1 subframe measurements

Unread post by piggdekk »

Hi Huib,
thanks a lot for the explanation. I'm not sure I understand what the 2.5mm measurement represents though. Am I correct assuming that the offset between mid and rear mounts dhould be 18mm, or should it be 20.5? I am also building a jig to fix check and fix the frame, that's why I really want to understand the measurments.
If the offset between front and mid mounts is 47 mm I need to do some surgery on my subframe, currently the offset is 42-44mm.

The car is fully stripped (by pyrolisis), and both inner and outer left sills will be replaced together with both rear frame support mounts. This is a former Gr.4 car that has never been used on the road and was parked in '92. It has quite a racing pedigree that includes 5 targa florios. There is relatively little rust on the body, but lots of spot welds are gone, and the body will be seam welded.
Fulvia Zagato 5.jpg
Fulvia Zagato 3.jpg
Fulvia Zagato 1.jpg
This is the car as I found it, it has got most of the original Gr.4 parts.
intera2.jpg
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