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Researching a Le Mans 260Z - Info appreciated


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#21 Brabham

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Posted 16 March 2011 - 06:33 PM

Awesome info thanks Alan and others.  :)

Now for the obvious questions - I assume none of these parts are available from Nissan anymore? Who are the sources that you can buy the body work parts from? I imagine you would want to buy the g-nose, front spoiler and flares from the same supplier to ensure that they all fit together properly. The rear spoiler obviously not as critical but nice to get from the same source - on this I am surprised by the height of it, I would have thought the drag would have been considerable on such a high speed circuit as Le Mans was in the 1970s.

On the wheels, any idea what a set is worth and where I could source them. Additionally would it be wise to use them on a track car at speed these days or are they likely to fracture given the nature of the casting and their age?

Any idea of what top speed the 1976 car clocked down the Mulsanne?

Highly interested on all the other difficult bits to obtain that were on the car - please proceed to talk aforementioned leg off donkey on what these are and where they can be found.

Thanks for all the info, as far as I know, I have not seen any replicas of the 75 or 76 Le Mans cars, everyone seems to prefer to build BRE cars which also look nice. Although I think the 76 Le mans car is the best looking zed ever. :)

#22 peter mc

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Posted 16 March 2011 - 06:57 PM

it looks very much like the imsa cars from that time they all had 15 by14 in wheels g nose and flears

#23 NZeder

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Posted 16 March 2011 - 07:01 PM

These guys do replica body work
http://www.aritaspee...logue/aero.html

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#24 Zedman240®

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Posted 16 March 2011 - 07:33 PM

With the question about what speeds was the zed doing on the Mulsanne straight, I read they were doing lap times of around 4:30?ish.. So if you can find out info and times on cars doing similar laps not too long ago before they changed the track, you should be able to find out avg speeds.

#25 Brabham

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Posted 16 March 2011 - 07:46 PM

Good idea Zedman, although I was more interested in the outright top speed. Just did a rough calc based on lap distance of 13562m (think it is around that) and 270 seconds. This gives an average of 180Kmh which is pretty decent. Would have thought the zed would get close to 250 Kmh top speed.

Thanks for that N Zeder. There are a few differences between that body and the Le Mans body, the rear wing is different as are the side strakes and outlets in the rear of the wheel arches. Looks like a decent body kit though and pretty close to the Le Mans body. Interested in any other suppliers of the LM body kit that may be out there.

And those Kobe Seiko 4 spoke mags are a work of art... ;D

Cheers.

#26 acf321

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Posted 16 March 2011 - 08:04 PM

Hey Brabham (and others)

I seriously like the way you're thinking on this project, and I for One would be very very interested in seeing you getting this project done. If there is anything I can do, just give me a shout. This could be one hell of a car when done. Most of us guys are doing our own interpretations of what we like in a Zed for our own purposes, but your LeMans replica is a real gem, and as Alan points out is hugely unique, and holds a special significance in the history of the marque.

The fact that Nissan went head to head with the establishment, on their turf, and went to such lengths in terms of engineering, ie wheels, engine, aero and transmission is very interesting, and underpins the relevance of the 240 and 260Z and real sporting legends.

I would be very interested in some of the stats, Alan if you know such as; 1) transmission type and gearing ratios, 2) diff spec, what was the ratio, and was if LSD, 3) top speed, 4) peak HP, and RPM of that motor, 5) weight, and so on. Also, was that a metal car, or did it comprise many FRP, or other panels? 

Go for it I say Brabham, and as for one of those trick heads .. count me for one. We only need another 497 takers!

Thanks for the great read, and by all means let me know and i'll take you over to see the Hornet

Cheers

Adam







#27 Brabham

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Posted 16 March 2011 - 08:28 PM

The peak HP was 300 - they bolted this motor in on the Thursday just before the race which upped the output from 260 HP from the previous one. As to the other stats, I am not sure. The 240/260Z was such a versatile car being applied to the Safari Rally and circuit as well, special credit goes to it for making it into Le Mans given the nature of the circuit. It only just managed to qualify.


#28 HS30-H

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Posted 16 March 2011 - 10:18 PM

The peak HP was 300 - they bolted this motor in on the Thursday just before the race which upped the output from 260 HP from the previous one. As to the other stats, I am not sure. The 240/260Z was such a versatile car being applied to the Safari Rally and circuit as well, special credit goes to it for making it into Le Mans given the nature of the circuit. It only just managed to qualify.


More stories via the Autodiva forum ( commenting on gossip and stroke-pulling of the time ) that need to be taken with a big pinch of salt. One of the main contributors to that thread spent a long time a few years back pumping me for information and hard data about the car, and a few people have added press reports and other stuff into the mix. For me, the "300HP" engine-switch story just doesn't add up. Why? Well, the post-crash photos show the car still fitted with the 'Safari' FIA head and ECGI system ( not to mention the driver-controlled engine oil top-up reservoir system ) with all its dedicated plumbing and wiring, which is exactly the engine configuration that the car used in 1973 when the factory built it, and when it went to South Africa for the Springbok Series races. If there was an engine switch just before the '76 race, then what was installed in the meantime? I say its a smokescreen, and the clue is in the last line I quoted above....

They just managed to qualify in '75 ( they were lucky, as a dispute between some of the Ferrari-running teams and the ACO bumped them up from being reserves to actually taking part in the race ) and were slow. This probably as much due to driver quality ( no offence ) as to lack of proper preparation / equipment and the fact that the car was already getting old and was not necessarily suited to the Le Mans track. Remember that this was a car that had been built by the works in Japan, had raced / tested in Japan and then been sent to SA to race. It was left there - along with a limited kit of spares and data - in the hands of people who were not necessarily going to be fully familiar with it, and who did not have the factory mechanics to hand after their first race. With the cancellation of the Springbok Series, the car was eventually rescued from redundancy by the well-connected Schuller, and only got on the reserves list for the '75 Le Mans due to some clever lobbying / 'not-what-you-know-but-who-you-know' and some iffy paperwork. Having completed the '75 event ( not without some long stops ) and placed in class, they were automatically bumped up the queue for the '76 Le Mans, despite the protests and misgivings of other teams and drivers. Faced with all this lobbying, the team produce a story that they have switched their engine to some new demon tweeked '300ps/hp' unit ( from where?! ) and assure the ACO and their fellow competitors that they will be faster come the race. It's just a smokescreen, I'm certain of it. The engine was the same basic unit all along, and the '300ps/hp' is a nice round figure that appears rather conveniently....

About that '300ps/hp' figure: The car ( along with a sister car ) went to South Africa with data from the works team. The 'Safari' headed car ( running in Group 4 with local drivers ) was quoted at 262ps @ 7600rpm and 25.5kg-m @ 6000rpm, whilst the 'LY' crossflow headed sister car ( running in Group 5 with two Japanese works team drivers ) was quoted at 275ps @ 7200rpm and 29.8kg-m @ 5,600rpm. You can see that these are real endurance racing specced engines, designed to churn away lap after lap for hours and hours on end, with fuel stops to top up their 120 litre tanks. So the '300ps' quoted for the '76 Le Mans car - USING THE SAME ENGINE CONFIGURATION THAT WAS '262ps' ACCORDING TO THE WORKS TEAM - is more than that for its LY-headed sister, which went back to Japan after SA. Doesn't quite add up, does it?

I would not draw any conclusions from the lap times / top speeds of the car at Le Mans either in '75 or '76'. In the '76' event they at least had a couple of more capable drivers on board, but the car had not been built by the factory for Le Mans, was already old, and was running with limited resources by a team that was trying to punch well above its weight. To be blunt, they were out of their depth.

More on the car specs anon ( got some work to do here! ), but I just want to mention one thing, Brabham. Please bear in mind that the '76 car represents something that crashed with fatal consequences for its owner / driver. There's some baggage that comes with that. You might see it as a 'tribute' to build a replica / lookalike, but it may offend others - particularly if they were close to SION Auto / Haller or the others. Please bear that in mind.

And quite apart from that, the '76 Le Mans getup is bloody awful! A half-hearted and several years too late attempt at 'Pop Art' by somebody's well-meaning mate. The car looked its best in its factory colours / configuration ( '73 Fuji 100km / '73 Kyalami 9hrs ) in my opinion......

Cheers,
Alan T.       



#29 Brabham

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Posted 17 March 2011 - 07:00 PM

Thanks Alan,

this has all been incredibly interesting, have loved hearing the history of the car. Hope to hear more on the availability and sources of all the various bits and pieces.

I am conscious of the tragic history of the car and owner, and if I were to build a replica, it would be without the "Sionautos" livery and a few other changes here and there to the paint scheme so as to be sensitive about the history of the car. For me it is a beautiful looking car with a deep history, and the intention is not to offend anyone, it is a great shame the accident happened  :'(

If I were to build it it would be a loose replica given availabilty of parts is virtually non-existent and terrifyingly expensive. The FIA head looks cool, but I imagine the ECGR and oil top-up system are impossible to locate and a nightmare to setup and operate (mainly the ECGR).

Can LY crossflow heads still be found and did they run carbs or injection/throttle bodies? That would be a cool engine build to do. Also interested in potential bodywork suppliers.

Thanks and look forward to learning more from your next post.  :)

#30 NZeder

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Posted 17 March 2011 - 07:40 PM

Can LY crossflow heads still be found and did they run carbs or injection/throttle bodies?

You have a house to sell? If yes you might have a chance of getting hold of one - but first you must get the owner to part with it :(

I believe both carbs and injection was used on the LY heads. Alan can confirm.

#31 Brabham

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Posted 17 March 2011 - 08:07 PM

How much would an LY be worth if one could be found? Anyone ever seen one for sale?

Also anyone ever seen a set of those Kobe Seiko wheels for sale? eBay Japan?

Cheers.

#32 NZeder

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Posted 18 March 2011 - 01:03 PM

I found some pics of a real LY online - If you click the image you will redirect to the source - now if I could just my hands on one and see if kiwi-cylinder heads could remake a few.......(dreams are free - would have to get permission from Nissan I would guess as it is there IP after all)

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#33 zedrally

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Posted 18 March 2011 - 04:39 PM

.....(dreams are free - would have to get permission from Nissan I would guess as it is there IP after all)


How would you go with the TC24-B1 Twin-cam crossflow head made by O.S.Giken ?

One question I have on this is is it the same head as the LY ?

#34 .

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Posted 18 March 2011 - 04:54 PM

I don't get how that sprocket could fit that setup....is there only one for two cams?......or is there two? and then how would thefit next to each other.......wowser!!

#35 PZG302

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Posted 18 March 2011 - 06:09 PM

The LY head was a 2 valve SOHC crossflow head.

#36 NZeder

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Posted 18 March 2011 - 06:13 PM

LY = Nissan 1970's (and early 70's at that) SOHC, 2 valves per cylinder Cross Flow FIA approved

TC24-B1 = OS Giken 1980's DOHC, 4 valves per cylinder cross flow - non FIA approved - I believe 12 made in the first batch, some more made later from different alloy = did not last. Currently 6 more getting reproduced with some improvements/modifications to the design of cam towers and like.

If you are going to remake a head an LY 100% replica would be the way to go as you can use this in classic racing/HTP/FIA group 4 or 5 replica.

#37 zedrally

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Posted 19 March 2011 - 04:37 PM

LY = Nissan 1970's (and early 70's at that) SOHC, 2 valves per cylinder Cross Flow FIA approved


Yep it is, but where does the Giken head fit into the overall picture ?

It wasn't a competition part, it wasn't allowed in the US, yet it put out 15-20% more horsepower than the LY, yet there was no avenue for any vehicle with one fitted to run in that I can find, except for a rally spec 280ZX that ran in the US for a SCCA rally, which poses the question if it was allowed as a rally spec, why not for circuit ?

#38 NZeder

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Posted 19 March 2011 - 05:32 PM

Yep it is, but where does the Giken head fit into the overall picture ?

It wasn't a competition part, it wasn't allowed in the US, yet it put out 15-20% more horsepower than the LY, yet there was no avenue for any vehicle with one fitted to run in that I can find, except for a rally spec 280ZX that ran in the US for a SCCA rally, which poses the question if it was allowed as a rally spec, why not for circuit ?

I guess it comes down to what a circuit race organiser will permit - if you can convince someone who runs a race series to let an OS Giken head run then all good but that will be a hard road I bet, it is hard enough to get items listed on the sport option catalogue included let alone a very limited production non factory part.

At least with the LY - it was FIA approved for Group 4 and 5 Appendix J for the given period = you can build one up as an Appendix K HTP car - and that should not be turned away by anyone if the honour FIA Appendix K (for the given Appendix J period)

I have been reading a bit on the HTP stuff and Appendix K (for the given Appendix J period) and basically what is on the FIA papers or factory specs/options catalogues is what goes all other mods are out even if you can proof a car ran with an OS Giken head or other mods if the FIA does not have a homologation paper for a car with that mod you can't run it. Now my understanding is that back in period the US racing was not FIA approved ie SCCA, IMSA etc so all S30 or S130 mods that were done in the US in period are out as far as the FIA are concerned/HTP unless the same mod was listed on the FIA homologation papers - see where this is going....

Again if you were going to get a new head that is FIA period correct and (more to the point) legal then one of the FIA approved heads is the only option (be it rally head like that in the pics HS30-H posted or the LY shown in the pics above). Now depending on which class/group the car is build for in theory engine mods are also limited to stock/options catalogue parts  (however most, even FIA HTP papered cars, have bent these rules)

All of this stuff is a little off topic but sort of related to the Le Manns car as it was an event run under FIA rules so the cars were all meant to comply with the Appendix J rules of the day.

#39 peter mc

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Posted 19 March 2011 - 06:01 PM

NZeder did the ly req different pistons and did the head make good hp over a race L head . just curious..

#40 zedrally

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Posted 19 March 2011 - 08:11 PM

For some reason my reply has not appeared to NZders post.....




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