1970 240Z Works Rally - the road to restoration

[xs10shl]

On 4/17/2023 at 2:29 AM, HS30-H said:

Something we have discussed before, but is it not a possibility that OWSS simply supplied and fitted a set of the taller RAC type springs to use on the same Monte struts originally fitted to the car? I would think, what with Works parts being in short supply in-field (I am in possession of much period correspondence where OWSS, Datsun UK and various privateers were all trying to get hold of Works-specific spares in order to use Works cars that they had care of) that could have been a possibility.

Just to follow this line of thinking you've proposed: It's indeed my hope that I can retain the Works strut assembly, and simply replace the spring with a shorter one, and have that work.  This is a straightforward upgrade to many a stock S30 strut, with the substitution of Eibachs for the standard springs - something I've done myself on two S30s.  That said, I do wonder whether there was an alternate Works fixed strut assembly akin to the racing 54302/3-E7212, perhaps used within the Works racing team.  This is listed in my 1974 parts manual as lowering the car 2 inches.  Did the Works team (and others) perhaps use the lowering spring 54010-E7210 with the rally struts to achieve the same effect?  If it worked this way in period, it would reduce the need to modify several sets of struts for different ride heights. It would be helpful to know the height of these racing springs, as well as the height of the fixed spring seat on the racing strut itself.  

I don't know when the Works team switched to adjustable height struts. If it was after 1972, then It would be helpful if an enterprising individual crawled under #11 and #5 to take a look, and do a quick measurement of the spring seat height.

[edit - 1974 Competition catalog page added for clarity]

 

Edited May 9, 2023 by xs10shl

[xs10shl]

Part three of the Works Rally Struts show-and-tell: Rear Struts

I only have the L/H part number here, because the tape on the right strut has peeled off (or was removed): Y9821-55303. Rear springs are listed as Y9821-55020 2.98.  Rear spring diameter is 12mm, and a height of 308mm. The Strut tube is slightly shorter than stock at 15.25", while stock tubes are approximately 16". The spring seat is also about 1/2" lower. In thinking about this - a lower spring seat means a slightly longer spring, but a shorter strut tube means less potential shock travel.  As both the struts have the same construction and dimensions, I'd venture that the right strut p/n is Y9821-55302.

The front tube spring seats are actually set about an inch higher than stock, with the strut tubes being approximately the same length. 

 

Edited May 9, 2023 by xs10shl

[HS30-H]

On 5/8/2023 at 8:36 AM, xs10shl said:

@HS30-H requested a few specifics about the parts, which are shown below, for discussion.  For starters, the RH/LH part numbers are Y9821-54302 and Y9821-54303, with a spring part number of Y9821-54010-1.  There does not appear to be a part number on the strut shock absorber.  All this seems to potentially coincide with a later parts-manual listing for competition rally parts 54302-E7220, 54303-E7220, and 54010-E7220.  [edit: just for reference, stock strut components also have the 54302, 54303, and 54010 prefixes]

I've been away on a trip to Japan, so a little late answering. Sorry.

The 54302/54302/54010 etc etc prefixes on the stock & option strut components simply identify the part according to the Nissan parts numbering system, where 54 denotes front suspension section, 000 up denotes front springs, 200 up spring mounting parts, 300 up suspension crossmembers & 400 up suspension assembly parts. The Competition Department in Japan used these as suffixes in their unique (Works) part numbers, so I guess it makes sense that they correspond somewhat.  

On 5/8/2023 at 8:36 AM, xs10shl said:

Some observations: The strut housing and strut itself appears more substantial than a standard strut, although I don't have the parts in front of me to give accurate measurements - everything is out for analysis and rebuilding, so it might be awhile before I can have exact dimensions to share. One thing we did capture is the front spring height, which is 266mm.  This matches the listed height of the competition rally spring 54010-E7220. 

I'm not sure that the E7220 Rally Option struts and springs are going to be much use as reference for you. I own a set and they have looooong tubes and looooong springs, putting the car up at 'Safari' type ride heights for max travel and ground clearance. They are oil-filled and also gas-charged, but I'd say they are a step below the Works type parts in sophistication and build quality. They were probably OK for a 'Clubman' type rally car in period, but my friend Kevin Bristow used them on his car 'OMT' (prepped in period by Old Woking Service Station) and found they they soon overheated on rough stages.

Some photos of my set for reference:

 

[HS30-H]

In my black museum of leftover Works rally parts, I have a front strut that came to me described as a 'Monte Carlo' tarmac setting item. It carries Works part number Dymo tape labels 'Y0901-54302' and has the proper Works type Halda drive take-off.

I will dig it out of storage and take some measurements.

[HS30-H]

On 5/8/2023 at 6:26 PM, xs10shl said:

I don't know when the Works team switched to adjustable height struts. If it was after 1972, then It would be helpful if an enterprising individual crawled under #11 and #5 to take a look, and do a quick measurement of the spring seat height.

The switch was at some point in 1972. Both the extant remaining '71 season cars - '8511' '71 East African Safari Rally winner and '3640' '71 RAC Rally car - have fixed platform struts, although the Safari car has the type with the strut tube that detaches from the hub casting.

The other two extant remaining cars - '4150' '73 Monte 3rd place winner and '7924' '73 Safari winner (originally a '72 RAC car) - both started out with adjustable platform type struts, so not much use as reference points here I think?     

[xs10shl]

On 5/11/2023 at 8:10 AM, HS30-H said:

The switch was at some point in 1972. Both the extant remaining '71 season cars - '8511' '71 East African Safari Rally winner and '3640' '71 RAC Rally car - have fixed platform struts, although the Safari car has the type with the strut tube that detaches from the hub casting.

The other two extant remaining cars - '4150' '73 Monte 3rd place winner and '7924' '73 Safari winner (originally a '72 RAC car) - both started out with adjustable platform type struts, so not much use as reference points here I think?     

Agreed, sounds like they are all different.  I had thought that perhaps 4150 was early enough to have fixed struts. 

[xs10shl]

On 5/11/2023 at 8:03 AM, HS30-H said:

In my black museum of leftover Works rally parts, I have a front strut that came to me described as a 'Monte Carlo' tarmac setting item. It carries Works part number Dymo tape labels 'Y0901-54302' and has the proper Works type Halda drive take-off.

I will dig it out of storage and take some measurements.

 

Yes, please!  Knowing the spring perch height, and overall strut height of the Tarmac strut casings would be very useful. If they are identical measurements to mine, or even very close, that would lead credence towards re-using my casings with shorter springs to create the proper ride height.

[HS30-H]

On 5/12/2023 at 11:40 PM, xs10shl said:

Yes, please!  Knowing the spring perch height, and overall strut height of the Tarmac strut casings would be very useful. If they are identical measurements to mine, or even very close, that would lead credence towards re-using my casings with shorter springs to create the proper ride height.

OK, here we go. Please excuse the crappy graphics...

My Y0901-54302 (it came to me as an 'ex-Monte Carlo' Works strut) measures as follows:

Dimension 'A' (spindle/hub casting to centre of spring perch weld) = 240mm
Dimension 'B' (centre of spring perch weld to top of damper retaining cap) = 115mm

Strut tube diameter is 51mm
Damper rod diameter is 22mm
Spindle is drilled for Halda cable with outer cable connector welded to strut tube with steadying bands.
This appears to be the 'early' type Works Tokico-built unit without gas charge to mitigate oil foaming, as seen slightly later.

Can take any other measurements you need.

Reference photos:

 

 

[Namerow]

Please explain how the drive for the Halda unit's is accomplished.

[HS30-H]

13 minutes ago, Namerow said:

Please explain how the drive for the Halda unit's is accomplished.

The front spindles were drilled for the Halda drive cable to pass through, with a specially-adapted hub bearing cap holding the (square) end of the cable so that it was forced to rotate with the wheels. The Haldas were geared to translate that wheel rotation into an accurate measurement of distance travelled per revolution. The Navigators were equipped with pre-set computations for different tyre selections.   

Note the special bearing cap and its tabs which were clamped firmly between the wheel and hub:

 

 

[HS30-H]

A more complete example, perhaps:

[xs10shl]

On 5/17/2023 at 7:21 AM, HS30-H said:

OK, here we go. Please excuse the crappy graphics...

My Y0901-54302 (it came to me as an 'ex-Monte Carlo' Works strut) measures as follows:

Dimension 'A' (spindle/hub casting to centre of spring perch weld) = 240mm
Dimension 'B' (centre of spring perch weld to top of damper retaining cap) = 115mm

Strut tube diameter is 51mm
Damper rod diameter is 22mm
Spindle is drilled for Halda cable with outer cable connector welded to strut tube with steadying bands.
This appears to be the 'early' type Works Tokico-built unit without gas charge to mitigate oil foaming, as seen slightly later.

Can take any other measurements you need.

Reference photos:

 

 

 

Just to circle back to this with some measurements: Dimension A and B match the front strut housings on my car, but the damper rod is thicker at 25mm, perhaps for off-road use? The only other difference of note is the TKH vs TKJ designation on the strut housing.  At any rate, the identical sizes of the strut housings lends credence to the theory that at least some suspension setups used the same parts. So it seems reasonable that I may be able to re-use the strut housings with different dampers and shorter springs, and achieve a close result.

Edited May 22, 2023 by xs10shl