1973 Indy4900 (LHM version) suspension question

Hi,

I have bought an Indy (AM116/49/1838) and I am currently lightly restoring and sorting out a few snags on her.

When driving it home I experienced the car as very low and scraped over every speed bump. So I removed one of the front springs to see if the they are in need of changing. My initial plan was to change these, and to restore (re-strengthen) the rear leafsprings to get her back to original riding height.

MIE are offering these springs:

Front Coil Spring Set

New production front coil springs, patterned from the original factory part.
Part Numb. 107/SA 55013
Black powder coated semi-gloss finish.

Rated at 435 lb/inch
Free standing 13.25" (320 mm)

Supercedes: 116/SA 66900

Applications:
Mistral, Quattroporte I, Mexico
Ghibli, Indy, Khamsin


So I thought it would make sense to figure out if the springs in the car are shorter (tired original springs) than the 320 millimeter, but the spring I removed measures 380 millimeter.

I am now wondering if it should be different front coil springs on the Indy4900 for some reason, or are the 380mm springs unoriginal and probably doesn't have the 435 lb/inch compression as they should.

I would truly appreciate if someone would advice me of what to do next.


Brgds

Kim

Norway

 

do u have 15in. wheels?

 

Hi Kim,

Welcome to F-Chat.

I don't know about the Indy, so I can't say.

For starters, I suggest that you contact MIE for clarification. It's possible that they have a mis-print in their catalog. Maybe the 320 mm is actually the installed static measurement?

Carmine

 

Pay attention to what he's saying here though I doubt a late Indy would have the 14" wheels. If it does then the later 15" wheels would help.

 

Bundas: I have the 15 inch starburst Campagnolo wheels, shoed with Pirelli P4000 205/70 VR 15.

MK1044: I will eventually contact MIE prior to making this winters order of parts, but I hoped to be able to tap into the vast amount of knowledge by the members of this board to get to the bottom of the different spring issue.

For reference: the front shockabsorber that I removed from the car along with the spring is stamped RIV 808 5C 10 449 It has 100 millimeter of travel and a total length of 340 mm.

In the mid picture (in the garage) the car is lifted up in the front for MOT suspension check, so it doesn't reflect correct ride height, the top & lower pictures does.


Brgds

Kim
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I have mailed MIE and also sent a mail to Fabio Collini

Brgds

Kim

 

I had a set of new tires put on a friends Indy this summer, he has 15" wires, and we had a devil of a time getting on & off the drive-on style rack at the tire shop. It appears that they just do scrap on the bottom frame rails when going in & out of driveways with a dip.

You might just be experiencing normal behavior for that car ...

 

Thank You Staatsof! Good to hear that it is low from start maybe I should leave it as is, it's definately the cheapest and easiest route

I drove by the garage on my way home from work today, and measured the coilspring myself, it is 308 not 380 millimeter this makes more sense.

I received an immediate response from Fabio Collina prior to going to the garage, and Mr Cozza's coil spring drawings are stating they are supposed to be 304,5 millimeters (mm) with 0,111 mm/kg compression and 18mm dia on the 52SCH5 (NOS) steel for the 66900 spring that the Indy is meant to have. Both this spring as well as the A-55013 Coil spring (for the AM 115, AM 107 and the AM120) have the bottom coil extend so as to function as support from rotating or shifting. The bottom coil spring plate on the indy has a recesse for this coil extention.

When I looked at the spring from my Indy it did not have this bottom extension tap (see attached pict of spring & shock absorber)

Brgds

Kim
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Received an answer from MIE today, they are correcting the spec's for the spring set they are selling (55013).

MIE Springs:
Height: 333 mm (13,125")
Wire diameter: 16,75 mm
Number of spring turns 6
Spring Rate: 435 lbs/in

Springs on my Indy:
Height: 308 mm
Wire diameter: 18mm
Number of spring turns 8
Spring rate unknown

OEM 66900 (Indy spring from Cozza's drawings)
Height: 304,5 mm
Wire diameter: 18mm
Number of spring turns 8
Spring rate: 0,111 mm\kg (assume this means 11,1kg\mm or 621 lbs\in)
Outer diameter: 130mm
Inner diameter: 102 mm
Spire Utili: 6,75 mm
Material: 52SCH5 (NOS) Pallinatura

OEM 55013 (AM107\AM112\AM115\AM120 spring from Cozza's drawings)
Height: 325 mm
Wire diameter: 17mm
Number of spring turns: 7
Outer diameter: 132mm
Inner diameter: 103mm
Spring Rate: 0,13 mm/kg (13kg/mm??? 728 lbs\in???)
Spire utili: 6,25
Material: unknown.

If I assume that MIE has done their homework and that the MIE springs are statically displacing the equal amount of weight similarly to the OEM 55013 spring, it would mean my car would be riding MORE than 2,85 cm (1.1in) higher than if I manage to source OEM 66900, this is based on the higher springrate of the 55013 coilspring over the OEM 66900 (13kg/mm vs 11kg/mm)

If I use the springs currently on the car and they would teoretically sit 3,5mm (0,1in) higher than OEM 66900.

If I manage to source OEM 66900 or reproduce them to 100% well I would get a 3.5 mm lower car...

I am leaning towards "stick with the springs I got on the car" or buy a set of MIE springs to test how it would look & feel.

What would you do in my shoes?

Brgds

Kim

 

Stuart at MIE is better at math than me, below are the correct lbs\in values for the springs.

MIE Springs:
Height: 333 mm (13,125")
Wire diameter: 16,75 mm
Number of spring turns 6
Spring Rate: 435 lbs/in

Springs on my Indy:
Height: 308 mm
Wire diameter: 18mm
Number of spring turns 8
Spring rate unknown

OEM 66900 (Indy spring from Cozza's drawings)
Height: 304,5 mm
Wire diameter: 18mm
Number of spring turns 8
Spring rate: 0,111 mm/kg

0.111 mm/KG
0.111 mm = .00437" KG = 2.205lbs.
1.0" / .00437" = 228.83 x 2.205lbs = 504.57 Lbs/Inch

Outer diameter: 130mm
Inner diameter: 102 mm
Spire Utili: 6,75 mm
Material: 52SCH5 (NOS) Pallinatura

OEM 55013 (AM107\AM112\AM115\AM120 spring from Cozza's drawings)
Height: 325 mm
Wire diameter: 17mm
Number of spring turns: 7
Outer diameter: 132mm
Inner diameter: 103mm

Spring Rate: 0,13 mm/kg
0.130 mm/KG
0.130 mm = .00512" KG = 2.205lbs
1.0" / .00512" = 195.31 x 2.205lbs = 430.66 Lbs/Inch

Spire utili: 6,25
Material: unknown.

I had a discussion with a friend that is restoring an Indy, he removed and measured his springs yesterday evening. His spring is like mine 8 turns, 18 mm thick and his was 311.

I got verification that the shock absorbers on my car are most likely original (probably restored a couple of times.) So I am assuming that the springs are original. Since the spec on Cozza's drawings of the 66900 spring was 304,5 mm and mine are 308 I think I will stick with them at least for the comming summer driving season.

Brgds

Kim

 

There should be a round rubber spacer on top of your springs. Are the spacers present?
Perhaps all you need to do is a add an additional spacer just to get a little more clearance.

Ivan

 

Who sells these?

I have similar problem on my Indy. 1971 car. Rides on 14" factory wheels. Clearance is really bad. I hit bumps on occasion....

But handling is awesome! Minimal roll!

But with new rubber spacer, maybe I can gain a quarter inch or something? Would be great!

Martin

 

When adding spacers, remember that you need to calculate the "Motion Ratio". That is the ratio between how much the body will raise compared to the amount of spacer installed in the spring pocket. The easy way to do this is to remove the wheel and measure a distance between the upper and lower ends of the spring as best you can. Then put a jack under the suspension and raise the front hub one inch. Then remeasure the spring distance. That will give you the amount of spacer needed to raise the car one inch. Most Italian cars of that era have motion ratios of about 2 to 1, so to raise the body one inch, you would need a 1/2 inch spacer. For example, on a Lamborghini Jarama that we just did, we needed to raise the rear of the car one inch. We calculated the motion ratio at 1.60, so a 9/16" spacer raised the rear one inch.

 

I have never shopped for them, perhaps MIE has new spacers. Below is from the Ghibli parts manual, it is #64.

Typically when the springs are removed the rubber spacer stays stuck to the chassis so many people do not even know they are there.

Ivan
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There wasn't any loose rubber spacer present when the spring was taken off the car. I plan to do some work on the car this evening, I will see if it the rubber is stuck to the chassis.

Mailed with Stuart@MIE last night, neither part 64 or 65 from the parts manual above is currently in MIE's inventory (parts number: 48001 & 47997)

Thanks Ivan!

Brgds

Kim

 

Looking back at the photo of your spring, you couldn't use the Ghibli spacer anyway: If I understand it right, the latter has springs with a flat top and bottom surface to rest on chassis and in the pan on the lower wishbone. They would in that case not be interchangeable.

Have you measured the overall height of your car? If ground clearance is not specified, this might give a clue.

Your car looks great, I like the late Indy's a lot.

Best,

Jack.

 

f308Jack, thx for your kind words!

In regards to the spring design, it has a flattened top, the bottom of it is just the ring. The ring fits the pan on the lower wishbone, but the coilspring doesn't have the "exit-tap" that there is space for in the pan and that Signore Cozza's drawings display.

The Ghibli & the Indy (AM 115 & AM 116) got the same front suspension main parts, it is Jaguar MK2 if I am not mistaking. The only parts I have seen so far that are different are the coilsprings.

The drawings from the parts manual for both cars are 100% similar. I have yet to compare the parts numbers for the spacers but I believe that there is supposed to be rubber spacers between the top of the chassis and the spring on my Indy as well. Here I have a picture from a friend that's restoring a 4700 Indy, on the lower part of the picture you see the rubber spacers (in the red circle). My friends front coil springs are identical to mine (OEM most likely) I also took a picture of my chassis last night, and to me it looks that it's something in the support area for the coilspring, if it is the rubber spacer or a metal ring. I am not 100% sure since I didn't have time to lay down and inspect it properly.


Looking at the picture of my Indy's right spring support, in the interior of the support it looks like a fatigue crack doesn't it?



Brgds

Kim
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Update:

the crack wasn't metal fatigue, it was an optic illusion.

Ivan, thank you, I believe you hit the bullseye!

I received the rubber spacers from Campana last week. The ones that are supposed to be positioned between the top coilspring support and the coilspring.

As Ivan suggested, my Indy didn't have these rubber spacers, so now I will gain 3/4th of an inch or thereabouts in height on the front suspension when I install them. We are on the right track!

Tires:
The car was set up with Pirelli P4000e Super Touring 205/70ZR15 when I bought it.
When looking for the reason behind the low car syndrome, I also looked into the rolling diameter.

The first Indy's were delivered on 205VR14 tires these would be 685mm diameter if they were Michelin XWX's. The 205VR15 Pirelli Cinturato's were 707 millimeter in diameter for reference. In the manual it states that the Indy4900 is supposed to have 205VR15.

The spare wheel that is in the boot has a stone hard Michelin 215/70 VR15 (683 millimeter) on it, I think this tire is original. The wheel still has the Campagnolo stickers on it [see pictures]

The Pirelli's that are on the car are 665 millimeter in diameter. This is indicating that I have 42mm smaller diameter tires than the car was originally designed for. This gives me 21 mm (close to an inch) lower ride than it would have if it was set up with 205VR15 Pirelli Cinturato tires.

Since the Indy 4900 is from 1973, it was most likely not delivered with Pirelli Cinturato tires, it would be delivered with Michelin XWX imho.
Comparing rolling diameters, the Michelin XWX 205\70VR15 are 669 mm diameter, very close to the lowrider - Pirelli's - that are on the car, so miI ended up buying a set of 5 new 215\70VR15 XWX's, 683 millimeter in diameter, closer to the 707 millimeter target and is identical to the spare wheel. This gives the Indy 9 mm more riding height than what it has with the Pirelli tires + approximately 20 millimeters assisted by the front rubber spring spacers. Now focus will shift to the rear suspension and getting the leafsprings back to spec.

Other stuff that is currently being worked on:

Front mats:
I bought a set of QP3 brown rubber inserts for the carpets from Campana since the original ones are ruined. The passengerside rubber in the indy is much bigger, as shown on the picture. I am now sewing the old carpets with leatherette inserts in the same size as the original rubber inserts and saving the QP3 rubber inserts with the maserati logo for when I am making new mats. I have not been able to source the original sized passenger side rubber inserts anywhere.

Front suspension:
Replacing left lower balljoint dustcap & tidying up a little in the engine room.
I need to do a complete engine room paint job as a later project, if I am going to be able to use the car this summer. The focus now is sorting out mechanical snags, getting her tight, tidy & safe. I bought this car initially to be a strong driver rather than a concours queen, but I have a feeling that I won't stop at just making her a nice drive.

Seatbelts:
I have ordered a set of Stahl (ECE approved) static 3 point belts for the back seats, I want to be able to secure my kids in the back seats. I ordered static, because I don't want to have the rolls on top of the seats or hidden in the tank area. Unfortunately I wasn't able to source any nice Squirrel belts that could be used for this like the ones that are used for the front seats [see pict].
Does anyone have an idea of what was delivered as an option from the factory and if it is still possible to source?

Front parkinglight+turnsignal:
As part of the process from importing a vintage car to getting plates on it here in Norway, a MOT inspection is needed. This inspection happened the day after we came back with the car from Budapest, Hungary in the end of November. As you can probably understand, the car was far from showroom clean underneath after over 2000 km (1250miles) of travelling in rain&snowing conditions including a servo hydraulic pump oil leak that lasted the whole trip. The MOT inspector didn't want to listen to the story that the oil he saw everywhere was from the servo leak that we had sorted out.

He didn't like the combined orange turninglight & parkinglight that the Carello's are set up with and wanted me to mount new white parkinglights to be road legal.I don't want to mount anything exterior that wasn't on the car the day it came out of the Maserati Factory, I want the car to be original!

We solved this MOT demand with using a 2 coloured modern LED bulb in the original Carello houses, park light is now white, and the turn signal orange. Taking it back to original only involves a bulb change!

Side turnsignal light:
The MOT inspector didn't like the original front fender turninglights either...since he couldn't see the the turnlight from the required 30 degree angle view zone from the rear. (the wheel arch lip is hindering) He wanted me to mount a new side turnsignal behind the front wheel arch. I am not drilling a hole in the car. It would ruin it's looks and it isn't original! So we decided to mount the side turnlight on the Talbot mirror arm (glued). It takes max 10 minutes to remove these side turnlights completely [see pictures of mirrors]

Radio:
The 8-track that's in the car is missing the front and the radio part doesn't work, so I sourced a Becker Mexico casette player [middle in the picture] to replace it with at Retromobile last month. I will repair & source a new front for the 8 track and keep it for later.


brgds

Kim
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I asked and got today the following information with regard to Indy 4900 production numbers from Fabio Collina - interesting as I own #1808.

Ciao Colin,
the total number of Indy 4.9 produced is 299 (99 of the first series with Bonaldi servo brakes system, 200 of the second series with Citroen brake system).
The first Indy 4.9 produced (with Citroen brake system) was the *1808* (January 1973).

AM116/49*1808* --> 4.9 cc engine, 5 speed + R manual gearbox, external colour “Blue Ischia”, interior in white leather.
AM116/49*1838* --> 4.9 cc engine, 5 speed + R manual gearbox, external colour “Blue Ischia”, interior in white leather.
AM116/49*2036* --> 4.9 cc engine, 5 speed + R manual gearbox, external colour “Tabacco”, interior in white leather.

Ciao
Fabio

Given the above would mean and assuming all even numbers that the last Indy 4900 would be #2208 (200 x 2=400+1808=2208).
Cheers,
Colin

 

cwcmaser,

I appreciate you sharing this & congrats with having the first LHM Indy4900!

to make things interesting, in a typical maserati standard, I recently found out I might have the first LHM Indy4700

To explain: When I bought the car & drove it through Hungary-Austria and Germany to get home before the roads up here are salted, in end of November last year, I drove it very carefully... 100 miles into the trip home, the car was showing me signs that she wanted some immediate maintenance..when she was gulping servo oil through the left hood ventilation grille...long story short, I had bought a project!

The Indy was sold me 'as a strong, well maintained driver, not a concours winner' ..all the other Indy owners I had been talking with, had hangarqueens for sale. To me it was important to get an Indy with an engine that didn't need immediate total overhaul, I wanted a car I could use during summer 2013 and do a 'rolling-restoration' over a few years like I did with my previous Merak.

I wasn't able to inspect the engine number until I had done a proper engine wash, the previous owner had told me that she was a car with different engine/chassis number, I wrote the number down as well as a plated number on top of the engine and sent them to Fabio Collina. The answer I got back was:

[The only strange thing I have found is related to the number "3608" you have found. This number was an "internal" number used at the time of the production for logistic purposes. So the "internal" number "3608" corresponds to the engine of the Maserati Indy chassis # AM116*1578* which was a 4.7 litres.]

Does anyone know anything about AM116*1578? does she still exist? Did she ever exist or was she damaged beyond sale and used for spares?

So the next thing for me to do is to check the stroke, is it 85 millimeter well then it's a 4.7 and if it is 89 millimeter, then it's 4.9. The first thing I that I thought was that this car had an engine swap in it's early days, but the still present "internal" number on it might explain that Maserati, for some reason, used a different engine block when AM116*49*1838 was assembled in Feb 73.

cwcmaser, if you could, I would appreciate if you can send me whatever pictures you have of *1808, for comparing our two cars.


brgds

Kim

 

I tried to remove the left rear hub to change the brake disk yesterday but I didn't succeed.

I removed the center castle axle nut with the splint, I removed the bolts that attach the disc to the hub from the outside, I mounted an extractor to pull the hub off the axle. It didn't budge, I tried again this time applying propane heat, and it still didn't budge. I didn't want to overdo the heat because of the close proximity of the fuelpumps and hoses.

Am I missing something or does this require an hydraulic extractor using all 4 wheel bolts and an induction heat source to make it come off? If so, I will outsource the job but I would really appreciate if anyone could steer me in the right direction on this, I like to know how it should be done and I don't want to use brute force and risk destroying something while doing it.


Brgds

Kim
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Hello Kim,

If disc is similar to Ghibli, you don't have to remove hub,
just use puller against shaft end and jaws behind outer round edge.
Hub is very tight, better remove with shaft.

Regards,

Juha

 

Thank you Juha,

The Ghibli & the Indy both uses the Salisbury Differensial

Do I understand you correctly that you remove the whole driveshaft from the differensial?

Brgds


Kim

 

I removed whole shaft, because I changed wheel bearings too,

but if you want to remove brake disc only,
remove caliper and small screws, as you have done...
then hit disc out with hammer or draw with puller.
Disc should come out quite easily.

Juha

 

Thank you Juha!

kind regards

Kim