Maserati Khamsin

[hensj2]

Originally Posted by John Berg

This is my first test entry!

Hi John, best of luck. Should be a very intersting project. AM120US1222 is parked in Malmö most of the time, should you need to look at anything assembled.

Regards

/Henrik

[gopp]

Originally Posted by John Berg

Today I had a strange experience as the rear spring /coil is of different length and an aluminium spacer is installed to compensate the missing length – is this standard or a later rebuild??
John

This is right John. One coil one each side is shorter than the other. I can't remember which one, but I think the rear ones are longer.

[f308jack]

Originally Posted by gopp

This is right John. One coil one each side is shorter than the other. I can't remember which one, but I think the rear ones are longer.

Very interesting, something I never saw before. My immediate thought was that there should be symmetrical springs, but maybe different rates were chosen to avoid axle tramp with the high torque engine that feeds the power? From a theoretical standpoint I'd also say that the shorter springs go in front. Still find it very strange...

[au-yt]

Hi John
Marc this needs to go in your data base.
I would advise if you dont have a parts book they are essential to work out some of the details.

After rummaging through my pile of info on My Khamsin Restoration I found the information the Maserati factory sent me on the springs.

Stay with me on this one there is a bit of info.
The first 50 Khamsins had spring part no 76691 4 off position doesn’t matter.

Later cars
there are two part numbers 120SP84468 this spring goes at the front on both sides.
its dimensions are
397mm free length (uninstalled as per you picture) wire dia 10.5 , OD of the coil is 102.5mm
Dynamic load is 326 KGs at a compressed length of 166 mm static at 238Kgs at 228 mm

the other part number is 120SP84469 this is the rear spring on both sides.
its dimension is 392mm free length 11 wire dia and coil OD is 103.
Dynamic load is 383 KGs at a compressed length of 166 mm static at 278Kgs at 228 mm

If I may offer my own experience with Maserati springs is that the steel is very good quality but the heat treatment isn’t. I would advise that the info I have here is given to a spring manufacturer for them to reset and retemper the springs. My car was quite low in the rear and when fueled up almost sat on the ground.

As for the question of the spacers they don’t appear in the parts book but that doesn’t mean much there are quite a lot of items that don’t.

If they are 5mm thick this could be the case they could be factory as that’s the difference in the free spring length.
As you may have found there is quite a lot of preload on the springs when installed.

As a interesting thing I had the local Koni agent make me shocks for the car. they cut up the old ones fitted the end fittings and revalued them to suit these spring rates. They apparently came from an Aston Martin model they didn’t say. I suppose if I look hard enough I could see the original part number if you are interested.

[Freitag]

Hi.

When I dismanteled the rear suspension, I found no spacers, but the rear coils were thicker than the two in front (...of the rear, well, you know what I mean:-)

Helge

[au-yt]

Originally Posted by Freitag

Hi.

When I dismanteled the rear suspension, I found no spacers, but the rear coils were thicker than the two in front (...of the rear, well, you know what I mean:-)

Helge

Hi Helge

With a lack of real factory help cars finish up being a product of the previous owners not the factory. but as per my comment.
The wire diameter on the rear is 11mm the frount 10.5mm

Regards
Graeme

[John Berg]

Rear suspension issue – different coils.

Today I investigated the situation better based on the input her on the chat.
I have measured the coils as follow:

Short coils are 380 mm long and the outer diameter of 103 mm – material thickness is 11 mm.

Long coils are 400 mm long and the outer diameter of 103 mm – material thickness is 10,5 mm.

The two aluminium spacers placed on under the short coils – each end - are 5 mm and total together 10 mm which ads up a shorter coil 390 (10 mm) but at the same time whit slightly bigger material ( 11 mm)

Coils from the car front suspensions are 355 mm long and the outer diameter of 135 mm – material thickness is 17 mm.

It will be interesting to see if anyone knows the reason and can explain the right position!

Job of the day – hydraulics

May you all have a nice day!
John

[John Berg]

Originally Posted by au-yt

Hi John
Marc this needs to go in your data base.
I would advise if you dont have a parts book they are essential to work out some of the details.

After rummaging through my pile of info on My Khamsin Restoration I found the information the Maserati factory sent me on the springs.

Stay with me on this one there is a bit of info.
The first 50 Khamsins had spring part no 76691 4 off position doesn’t matter.

Later cars
there are two part numbers 120SP84468 this spring goes at the front on both sides.
its dimensions are
397mm free length (uninstalled as per you picture) wire dia 10.5 , OD of the coil is 102.5mm
Dynamic load is 326 KGs at a compressed length of 166 mm static at 238Kgs at 228 mm

the other part number is 120SP84469 this is the rear spring on both sides.
its dimension is 392mm free length 11 wire dia and coil OD is 103.
Dynamic load is 383 KGs at a compressed length of 166 mm static at 278Kgs at 228 mm

If I may offer my own experience with Maserati springs is that the steel is very good quality but the heat treatment isn’t. I would advise that the info I have here is given to a spring manufacturer for them to reset and retemper the springs. My car was quite low in the rear and when fueled up almost sat on the ground.

As for the question of the spacers they don’t appear in the parts book but that doesn’t mean much there are quite a lot of items that don’t.

If they are 5mm thick this could be the case they could be factory as that’s the difference in the free spring length.
As you may have found there is quite a lot of preload on the springs when installed.

As a interesting thing I had the local Koni agent make me shocks for the car. they cut up the old ones fitted the end fittings and revalued them to suit these spring rates. They apparently came from an Aston Martin model they didn’t say. I suppose if I look hard enough I could see the original part number if you are interested.

Would be very interesting to find a way to get new rear shock absorbers - I have not yet seen on the net - and need four!

Kind regards John

[au-yt]

Hi John
The difference in the springs and why they are different probably has more wo do with material availability than anything else.
To get a specific spring rate there are some deciding factors. The Diameter of the wire is a key the Diameter of the coil and the the number of coils and finally the length of the wire used in the springs.
To get the specific rate they were after they needed to play around with the above info to get the rate and the frequency they were after.
I think from memory the spring rate is about 70 lb/inch frount and 80lb/inch or total of 150lb/inch. and Given they are close to the wheel means the rates are not that far off whats called the "wheel Rates"
The front is a different matter due to the angle and the distance from the center of the wheel. meaning the rates on the frount are rougly 350lb/inch but the true rate is probably close to 200lb/inch
there is probably 10 ways to achive the end result but each one has a compromise. whats in there is there compromise for comfort and handling.

You may find the spacer in the rear are someones idea of trying to raise the car alittle due to them saging.( they dont get that much shorter when they sag the get softer thats why they are close to the factory length this is why the rate per inch or mm is an important thing to measure.)
As for the coil diameter probably a a production change/different manufacturer.
the Shocks I have you wont se advertised or available anywhere. they were made by th KONI Agent in Melbourne by an ex Koni factory person who emigrated.
interesting the price of the 4 shocks at the time was the same as 2 genuine VIRO units!

Cheers
Graeme

[au-yt]

Some Detail photos of the Front spring in free length the the rear suspension.

[staatsof]

Originally Posted by John Berg

This is my first test entry!

They do park funny in Demmark ...

[Nembo1777]

Excellent people from 3 continents sharing advice on a restoration: this thread is really coming into its own!

I am off to Retromobile, a French friend of mine who I am meeting there has just found...a khamsin in a barn!

I am needless to say salivating like a waterbuffalo at the prospect of finding out more:-)

Will let you know after Paris.

Also at retromobile ZF is introducing remanufactured gearboxes, the type I beleive used in Khamsins. Will gather info.

Oh and one Khamsin hads been found near New York as well: will post photos Vin and details when I return.

Graeme: thanks I duly saved your suspension info.

Bob: Denmark is a small country so you have to be inventive in how you park:-)

John: good luck with your continued work!

best regards,

Marc

[Nembo1777]

Make that four continents: I forgot Jack in South Africa!

[gopp]

Originally Posted by Nembo1777

Also at retromobile ZF is introducing remanufactured gearboxes, the type I beleive used in Khamsins. Will gather info.

This is very interesting Marc. Please keep us updated, as I know of at least one Khamsin owner that wants to get rid of the slushbox . This will probably also mean that spare parts for the boxes also will be available again.

[wbaeumer]

Originally Posted by Nembo1777

Excellent people from 3 continents sharing advice on a restoration: this thread is really coming into its own!

I am off to Retromobile, a French friend of mine who I am meeting there has just found...a khamsin in a barn!

I am needless to say salivating like a waterbuffalo at the prospect of finding out more:-)

Will let you know after Paris.

Also at retromobile ZF is introducing remanufactured gearboxes, the type I beleive used in Khamsins. Will gather info.

Oh and one Khamsin hads been found near New York as well: will post photos Vin and details when I return.

Graeme: thanks I duly saved your suspension info.

Bob: Denmark is a small country so you have to be inventive in how you park:-)

John: good luck with your continued work!

best regards,

Marc

Marc,
PM to you!

Ciao!
Walter

[John Berg]

This is fun.....

Today I was in the workshop of the company making my new interior another week and they will be finished.

Today’s picture is very motivating to get going!

Kind regards John

[John Berg]

I have asked to get all the old leather should someone need to replace just a single part in and original cabin – its available!

John

[au-yt]

Just this one thread has 2 people having there cars retrimmed and if you include my car having new carpet last week that roughly equals 0.75% of all Khamsin production!
I need to get some more pictures of another one car being completed as I write this.

[au-yt]

Hi John
I thought you might find these of interest.

[f308jack]

The rear hatch pin looks like a standard Jaguar bonnet pin. They can be a source of trouble if they are not adjusted properly for both length and being exactly centreded to the catch.
Btw, are you sure that assembly is put together like it was done at the factory? To me it looks like the cup at the pin-end is the wrong way around: when open it shields you from making contact with the greasy pin. With the cup the wrong way round, also the pre-load of the spring increases quite a bit, which in turn necessitates slamming the tailgate harder than one really should.