DATSUN 240Z Euro Spec. Springs???

[Carl Beck]

....snipped..cjb....

I'll try to make it clear what I think the answer to that question is, but it is going to take a lot of cross-referencing and typing out. And even at the end of that, I don't believe I have - as I mentioned in my first post - the exact info that is being requested. However, maybe some of what I have will be useful.

....snipped..cjb....

Bear with me while I type all this stuff out....

Hi Alan:

The data provided is most helpful indeed. I'll cut/paste all this into a single table, and try to keep the Metric to US conversions consistant.. I'll also see if some of the Part Numbers have been changed over the years etc.

Bear with me... this may take some time...

thanks again,

Carl B.

[Carl Beck]

From the first UK-market Nissan 'R-Drive' parts manual:

*54010-E4104 - SPRING-FRONT RH ( ratio 1.49kg/mm ) - MANUAL ( exc. Europe ).

Hi Alan:

The above is the OEM Spring for the US/North American Spec. Cars as well.

*54010-E8101 - SPRING-FRONT RH - Europe.

( note that no spring rate is given ).

The above is what we know as the Euro Stage II Spring.

Rate is: 2.18 kg/mm or 122 lbs/in

*54010-E4107 - SPRING-FRONT RH - OP. ( Manual ) ( ratio 1.80kg/mm ) ( exc. Europe ).

The above is what we know here in the US as the Euro Spec. Stage I spring. It is listed in our Parts Manuals as "optional".

*54010-E4105 - SPRING-FRONT RH - For air conditioner - AUTOMATIC ( exc. Europe ).

( note that no spring rate is given ).

The above is listed here in the US as "Optional with A/C and A/T.

Spring rate is 1.49 kg/mm or 83 lbs/in.

*54010-E4102 - SPRING-FRONT LH ( ratio 1.49kg/mm ) - MANUAL ( exc. Europe ).

The above is the same as the OEM spring for the US/North American Spec. Cars.

*54010-E8100 - SPRING-FRONT LH - Europe.

( note that no spring rate is given ).

The above is what we here in the US know as the Euro Spec. Stage II spring.

Rate is: 2.18 kg/mm or 122 lbs/in.

*54010-E4106 - SPRING-FRONT LH - OP. ( Manual ) ( ratio 1.8kg/mm ) ( exc. Europe ).

The above is known here in the US as the Euro Spec. Stage I spring. Listed as "'Optional" here in the US Parts Catalogs.

*54010-E4103 - SPRING-FRONT LH - For air conditioner - AUTOMATIC ( exc. Europe ).

( note that no spring rate is given ).

The above is listed here in the US as "Optional" with A/C and A/T

rate is 1.49 kg/mm or 83 lbs/in.

*55020-E4102 - SPRING-REAR ( ratio 1.8kg/mm ) ( exc. Europe ).

The above is listed here as the OEM rear springs for the US/North America

*55020-E8100 - SPRING-REAR - Europe.

( note that no spring rate is given ).

The above is listed here in the US as the Euro Spec. Stage II spring.

Spring rate is 2.5 kg/mm or 140 lbs/in

*55020-E4201 - SPRING-REAR ( ratio 2.0kg/mm ) ( Opt. )

The above is listed here as the Euro Spec. Stage I spring and optional.

My head hurts already. I'll have a cup of coffee and then start typing out some spring data that applies to the above numbers. Bear with me.....

Hope I got that right...

thanks,

Carl

Carl Beck

Clearwater, FL USA

http://ZHome.com

[Carl Beck]

Some spring data. Not much, but it is all I have to hand at present.

*54010-E4107:

Spring constant: 1.80kg/mm

Inside diameter: 100mm

Free length: 331mm

Loaded length: 178mm

Typical loading: 274kg

*54010-E4106:

Spring constant: 1.80kg/mm

Inside diameter: 100mm

Free length: 319mm

Loaded length: 178mm

Typical loading: 254kg

*55020-E4201:

Spring constant: 2.07kg/mm

Inside diameter: 100mm

Free length: 356mm

Loaded length: 225mm

Typical loading: 296kg

Identification mark: Two yellow paint dabs.

...snipped..cjb.....

Hi Alan:

Great... that helps a lot.

Now all we need is either the Wire Diameter, or the Coil Diameter (coil dia. is measured from the center of the wire on one spring coil to the center of the wire on another spring coil - 180 degrees from the first). Since we know the Inside Diameter either the Wire Dia. or the Coil Dia. can be derived from the other.

Then we need to know how many coils are in the springs. Number of coils and/or Number of Effective Coils. Note: the number of coils might be say 10 but the number of Effective Coils could be 8.5 if the bottom coil is pressed together.

Everyone keep digging...

regards,

Carl B.

Carl Beck

Clearwater, FL USA

http://ZHome.com

[HS30-H]

Carl,

One thing I think worth mentioning at this point ( which may or may not confuse the issue more ) is that most of the UK-market cars seem to have turned up here with higher spring rates than the 1.49kg/mm quoted in the R-Drive parts manuals.

There is no written evidence to support this as far as I am aware, but many of the HS30 models imported to the UK between 1970 and 1973 appear to have been fitted with the E4106 / E4107 front springs and E4201 rears......

You will probably know that the UK market cars got a different damper spec than the USA market too. Higher rates of bump and rebound, which motoring journalists noted in original UK-market road tests. Of course, the 432 had higher damper rates, and the 432R had higher rates again. There were a lot of springs and a lot of damper specs in the S30 model family.

Nissan generally matched relatively low spring rates with very high damper rates during that period. In fact, the competition damper units ( especially those on the Works rally cars ) were extremely stiff when compared to their spring rate. Apparently the reasoning behind this was in some part to do with their philosophy for the Safari Rally: namely that stiff shocks wear out more slowly, and last longer on the stages. It was just the rest of the car ( and the occupants ) that suffered.........

Funnily enough, I can see an 'HS30' shock absorber / damper unit noted on the USA-market factory parts lists. I wonder why that was - any ideas?

[Carl Beck]

Carl,

One thing I think worth mentioning at this point ( which may or may not confuse the issue more ) is that most of the UK-market cars seem to have turned up here with higher spring rates than the 1.49kg/mm quoted in the R-Drive parts manuals.

There is no written evidence to support this as far as I am aware, but many of the HS30 models imported to the UK between 1970 and 1973 appear to have been fitted with the E4106 / E4107 front springs and E4201 rears......

Hi Alan:

Yes, that would be supported by Andrews reply at #9 also.

As the spring perch is higher on the strut, when the above mentioned springs are installed.. they can not be interchanged with the spring we are tracking. Nor can I find any source for them at present.

You will probably know that the UK market cars got a different damper spec than the USA market too. Higher rates of bump and rebound, which motoring journalists noted in original UK-market road tests. Of course, the 432 had higher damper rates, and the 432R had higher rates again. There were a lot of springs and a lot of damper specs in the S30 model family.

Actually no.. I had not researched the damper spec.'s - -that accompanied the various spring rates from Nissan/Datsun. For that matter it is next to impossible to get the technical spec.'s for any of the aftermarket units as well. Would be interesting to know.

So it makes us wonder which set of springs/struts were on the production car tested, as well as the shock rates used. Yes/No?

I've also noticed that the installed height of the various springs, would also change the relationship of front and rear ground clearance. That too would have an effect on lift at higher speeds I would guess.

I was aware that on the various competition cars shock absorbers and their valves could be changed and/or altered to provide local fine tuning. I have the Factory Race Suspension on my BRE Z and am finding it impossible to locate any parts to rebuild the shocks... err... dampers... (54302-E4622 and 54303-E4622 front struts, 55302-E4622 and 55303-E4622 rear struts).

I may just have to turn to the after-market and have a custom set built.

Nissan generally matched relatively low spring rates with very high damper rates during that period. In fact, the competition damper units ( especially those on the Works rally cars ) were extremely stiff when compared to their spring rate. Apparently the reasoning behind this was in some part to do with their philosophy for the Safari Rally: namely that stiff shocks wear out more slowly, and last longer on the stages. It was just the rest of the car ( and the occupants ) that suffered.........

Do you have any specifications for the springs used on the Factory Rally Suspension? I can not find the spec.'s anywhere. All I have to compare is the Free Length of the Race and Rally Springs.. Of course I have the Race springs so I can measure them... Do you know anyone that has the original Rally Suspension...that could take some measurements for us?

It's not critical, but it would be interesting to know..

Funnily enough, I can see an 'HS30' shock absorber / damper unit noted on the USA-market factory parts lists. I wonder why that was - any ideas?

Not really. Many of the JDM and Export parts not found as standard equipment on the US/North American Spec. cars - are listed and were available via Special Order over the Parts Counter at the Datsun Dealers. Many were also listed in the Datsun Competition Parts Catalogs though Nissan Motors USA.

Could have been just a way or generating additional parts and service revenue, by selling into the huge after-market for speciality and performance parts here in the US at the time.

The Dealership I worked at installed a lot of them for customers after they purchased their cars. (rear spoilers, 5spd.'s, lower ratio rear gears, stiffer springs etc.). I remember that my first 5spd. over the Parts Counter cost ... are you sitting down.. $375.00!!).

Since the Datsun 240-Z's sold here in the States, really had no true factory "options" (other than A/T) that the customer could select/order on his car... the customers here were hungry for items that could be used to "customize" or "individualize" their Z's, as well as increase the performance of the car.

The automotive after-market was fairly quick to supply a host of comfort, performance and appearance items for the 240-Z's. Many of which became "Factory Authorized" and were resold by Nissan Motors USA, with Datsun Parts numbers thourgh the dealer network.

regards,

Carl B.

Carl Beck

Clearwater, FL USA

http://ZHome.com

[HS30-H]

I was aware that on the various competition cars shock absorbers and their valves could be changed and/or altered to provide local fine tuning.

Well, on the true Works rally cars the damping rates were not adjustable on-car in the field. The damper units were made at the Factory rand that was it. Changing bump and rebound was only possible by re-valving, which meant stripping and re-gassing.

I have the Factory Race Suspension on my BRE Z and am finding it impossible to locate any parts to rebuild the shocks... err... dampers... (54302-E4622 and 54303-E4622 front struts, 55302-E4622 and 55303-E4622 rear struts).

Those numbers seem to relate to the later style units. Are you sure that they are correct? I would have expected them to have the E7213 second number on the BRE Baja car, or even to be the extra-long E7220 "Rally" struts with the fixed platforms? The E4622 second number doesn't seem to show up until around late 1975 according to what I'm looking at. Have you got the right numbers? Are they Atsugi, Tokico or Ampco-built units?

I think you will struggle to find genuine parts to rebuild them with. If it is just the seals that are at fault then you might be able to find equivalents, but any of the other internal hardware is rocking-horse sh*t. Why not consider putting cartridges inside the original outer tubes?

Do you have any specifications for the springs used on the Factory Rally Suspension? I can not find the spec.'s anywhere. All I have to compare is the Free Length of the Race and Rally Springs.. Of course I have the Race springs so I can measure them... Do you know anyone that has the original Rally Suspension...that could take some measurements for us?

Yes, I have first-hand Factory data on the true Works cars - but it is pretty complicated and you have to understand what was matched with what. As usual with race cars, the specs were something of a moving target, and you need to be careful not to confuse yourself.

Please don't mix up the Sports Option / Datsun Competition parts with the real Works suspensions. The Works competition department took the Sports Option parts and built new / modified units from them - with different parts, specs and hand fabricated details ( such as the tubes for the Halda drives on the front legs ). They were quite different.

I can try to help with regard to the spring data you need, but I'm scratching my head at those E4622 numbers you quoted because they seem to be later than they should be. The full numbers are stamped onto the strut tubes, aren't they? Were these the units that have been on the car all along, or were they sourced separately?

[Carl Beck]

Well, on the true Works rally cars the damping rates were not adjustable on-car in the field. The damper units were made at the Factory rand that was it. Changing bump and rebound was only possible by re-valving, which meant stripping and re-gassing.

Those numbers seem to relate to the later style units. Are you sure that they are correct? I would have expected them to have the E7213 second number on the BRE Baja car, or even to be the extra-long E7220 "Rally" struts with the fixed platforms? The E4622 second number doesn't seem to show up until around late 1975 according to what I'm looking at. Have you got the right numbers? Are they Atsugi, Tokico or Ampco-built units?

Hi Alan:

The part number data that was printed on the aluminum foil stickers affixed to the struts, was only partly visible... I have some pictures of them I'll try to get on-line, maybe you can fill in more of the missing/smeared lettering/numbers.

They are Ampco.. that was still clear on them. No.. I am not certain that they are the struts used at Baja. Mr. Brock is still looking for pictures from the period.. but originally the car seems to have been equipped with the Rally Struts (with fixed spring perches)... then changed later to the adjustable coil overs.. why or exactly by whom... is still TBD.

As you will see from the original data tags when i get the pictures on-line.... they are marked NISSAN S30 RALLY...

That is not to say that the struts weren't later modified with the coil overs.. the car was road-raced briefly by it's second owner..

I think you will struggle to find genuine parts to rebuild them with. If it is just the seals that are at fault then you might be able to find equivalents, but any of the other internal hardware is rocking-horse sh*t. Why not consider putting cartridges inside the original outer tubes?

Agreed.. that is most likely what I will do.. the restoration is primarily aimed at presenting the car as it originally appeared, and preserving the history... I seriously doubt it will ever actually be raced again.

Yes, I have first-hand Factory data on the true Works cars - but it is pretty complicated and you have to understand what was matched with what. As usual with race cars, the specs were something of a moving target, and you need to be careful not to confuse yourself.

Please don't mix up the Sports Option / Datsun Competition parts with the real Works suspensions. The Works competition department took the Sports Option parts and built new / modified units from them - with different parts, specs and hand fabricated details ( such as the tubes for the Halda drives on the front legs ). They were quite different.

Agreed... that was pretty much the path that BRE followed.. they used as much off the shelf stuff that Nissan could supply... then modified from there.

I can try to help with regard to the spring data you need, but I'm scratching my head at those E4622 numbers you quoted because they seem to be later than they should be. The full numbers are stamped onto the strut tubes, aren't they? Were these the units that have been on the car all along, or were they sourced separately?

The numbers are not stamped into the struts anywhere that I can find.. and I sanded them down to bare metal before refinishing them. They had aluminum foil type stickers, that had the information printed in ink on them. I haven't removed the rear struts yet.. and may be able to get some additional details off them, once I get them off the car.

At this point I do not know for certain when/who they were installed.. The one article done by a Magazine in 1973 used photo's of the car before it was actually complete... then the second owner converted some things for road racing.. and he very well could have modified/changed the suspension at that point... that would have been closer to the 74/76 time period you mention...

I'm in the middle of a major transition between computers right now..so as soon as I can find, publish the pictures of the struts and what was left of the stickers.. I'll get back with you.. (moving from a seven year old Mac G3 to a new G5... very painful experience.. upgrading and/or up-dating all the software and files etc..)

more later,

thanks,

Carl

[Carl Beck]

Hi Alan (everyone)

I've put a couple pictures of the labels that were on the struts at:

<a href=http://zhome.com/BRE/BREFrontSuspension.htm TARGET=New>http://zhome.com/BRE/BREFrontSuspension.htm</a>

Across the top of the label it "looks" like it say's

..............NISSAN

.........S30 RAC FOR RALLY

........ something/##6???..5402

..... ....... 73 5 10

The spring coils, number of turns and free length would seem to line up with the E4266, but that could be the case for the E7213 - may be the same basic part only with updated/later Part Numbers??

Any thoughts?...

regards,

Carl B.

[HS30-H]

........ but originally the car seems to have been equipped with the Rally Struts (with fixed spring perches)... then changed later to the adjustable coil overs.. why or exactly by whom... is still TBD.

I have a set of the E7220-type Rally Struts in one of my garages. I will go there over the weekend, dig them out and take some photos / measurements. What I can tell you for sure at this point is that the fixed-platform Rally Struts had very long tubes on them ( a fair percentage longer than the standard or adjusrtable-platform struts ). They were used with long springs, and the combination gave a pretty tall ride height and a lot of potential suspension travel.

Looking at the period pictures of the Baja car I must say it looks like it would have been on these long Rally Struts, judging from its ride height. The numbers and the dates would tend to point to the car using the Rally Struts originally too.

Those adjustable Ampco struts you posted pics of look similar to the later style. I have some Ampco adjustable-platform Sports Option ones and they too have the silver metallic foil labels. I shall have to photograph them and see what they say. I have some Atsugi adjustable-platform Sports Option items - but they certainly have different labels ( although they are also foil ).

The majority of true 'Works' gas rally struts I have seen were made by Tokico, and the competition department at Oppama used red Dymo tape labels on them, giving useful data. Some of the the later ( 260Z ) types had green Dymo tape labels. I love Dymo.

Have those front struts in your pictures got Halda drive tubes in them? I can see red caps. Are they on both sides?

I'll take some notes / photos when I am at the garages over the weekend. I'll also try to dig out some Works strut / damper / spring data from my records. Maybe some of it will match up with what you have.

Cheers,

Alan T.

[HS30-H]

I have taken a few photos, made some measurements and dug out some hopefully relevant data.

See it here: Option Struts and Springs

Cheers,

Alan T.

[Carl Beck]

Hi Alan (everyone)

Please Stand By... while I try to get everything that used to work perfectly well (slow but well) on my old Mac to work again on this blindly fast new one.

I may have to bring the old G3 back on-line...

This may take a day.. or two... sorry for the delay..

regards,

Carl

[Carl Beck]

Hi Alan (everyone):

I've added some pictures to the same URL

See: <a href=http://zhome.com/BRE/BREFrontSuspension.htm TARGET=NEW>http://zhome.com/BRE/BREFrontSuspension.htm</a>

Just scroll down the images.

It would seem that the lower spring perch, on the front BRE adjustable coil overs, covers the range of 266mm to 305mm. About the same height as the rear Rally Option struts you show (given that front and rears can't be directly compared). However the total length of the strut tubes on the BRE car are about 55mm less in total length (420mm vs. 365mm).

The springs - if I had to guess - look like they were from the Rally Option Struts.. as they are the same wire diameter... but they would appear to have been cut down.. from 267mm to 220mm. So the free lenght is about 2 inches shorter.. I'm not sure what that would have done to the installed height and thus the ground clearance/wheel clearance.. (I guess I'll have a better idea once I get the original size tires/wheels back on the car).

Yes - both struts have the... tubes for the Halda Drives - if you say that's what they are - I've not seen them on anything else, can you tell us more about them?... I can find no indication from pictures taken in the car (at least so far) - that they were used for Baja nor the Mexican 1000. They certainly wouldn't have been needed for the road racing to the car was put to later..

thanks for the help...

regards,

Carl